&EPA
            United States
            Environmental Protection
            Agency
            Environmental Monitoring
            Systems Laboratory
            P.O. Box 15027
            Las Vegas NV 89114
EPA-600/3-79-123
December 1979
            Research and Development
Trophic Classification
of Selected Illinois
Water Bodies:

Lake Classification
Through Amalgamation
of LANDSAT Multispectral
Scanner and Contact-
Sensed Data

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                  RESEARCH REPORTING SERIES

Research reports of  the  Office of Research and Development, U.S.  Environmental
Protection Ageney, have been grouped into nine series. These nine broad categories
were established to facilitate further development and application of environmental
technology.   Elimination  of traditional grouping was  consciously planned  to foster
technology transfer and maximum interface in related fields. The nine series are:


       1.   Environmental Health Effects Research
       2.   Environmental Protection Technology
       3.   Ecological Research
       4.   Environmental Monitoring
       5.   Socioeconomic Environmental Studies
       6.   Scientific and Technical Assessment Reports (STAR)
       7.   Interagency Energy—Environment Research and Development
       8.   "Special" Reports
       9.   Miscellaneous Reports
This report has been assigned to the ECOLOGICAL RESEARCH series.  This series
describes research on the effects of pollution on humans.plant and animal species, and
materials. Problems are assessed for their long-and short-term influences. Investiga-
tions include formations, transport, and  pathway studies to determine the fate of
pollutants and their effects. This work provided the technical basis for setting standards
to minimize undesirable changes in living organisms  in the aquatic, terrestrial, and
atmospheric environments.
This document is available to the public through the National Technical Information
Service, Springfield, Virginia  22161

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                                   EPA-600/3-79-123
                                   December 1979
    TROPHIC  CLASSIFICATION  OF  SELECTED
           ILLINOIS  WATER BODIES
        Lake Classification Through
   Amalgamation of LANDSAT  Multispectral
      Scanner and Contact-Sensed  Data
                     by
              D. H. P. Boland
   Advanced Monitoring Systems Division
Environmental Monitoring Systems Laboratory
         Las Vegas, Nevada  89114

  David J. Schaeffer and Donna F. Sefton
    Division of Water Pollution Control
 Illinois Environmental Protection Agency
       Springfield, Illinois  62706

             Robert P. Clarke
          Environmental Programs
 Illinois Environmental Protection Agency
       Springfield, Illinois  62706

           Richard J. Blackwell
    Earth Resources Applications Group
         Jet Propulsion Laboratory
        Pasadena, California  91103
 ENVIRONMENTAL  MONITORING  SYSTEMS  LABORATORY
     OFFICE  OF  RESEARCH  AND  DEVELOPMENT
    U.S. ENVIRONMENTAL PROTECTION  AGENCY
          LAS VEGAS,  NEVADA   89114

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                                 DISCLAIMER
    This report has been reviewed by the Environmental Monitoring Systems
Laboratory-Las Vegas, U.S. Environmental Protection Agency, and approved for
publication.  Mention of trade names or commercial  products does not con-
stitute endorsement or recommendation for use.
                                      n

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                                  FOREWORD
    Protection of the environment requires effective regulatory actions that
are based on sound technical  and scientific information.  This information
must include the quantitative description and linking of pollutant sources,
transport mechanisms, interactions, and resulting effects on man and his
environment.  Because of the complexities involved^ assessment of specific
pollutants in the environment requires a total  systems approach that
transcends the media of air,  water, and land.  The Environmental Monitoring
and Support Laboratory-Las Vegas contributes to the formation and enhancement
of a sound monitoring data base for exposure assessment through programs
designed to:

      •  develop and optimize systems and strategies for monitoring
         pollutants and their impact on the environment

      •  demonstrate new monitoring systems and technologies by
         applying them to fulfill special monitoring needs of the
         Agency's operating programs

    This report describes in detail a project utilizing a combination of
LANDSAT-1 multispectral scanner data and contact-sensed data for the
classification of selected lakes and artificial reservoirs in Illinois.   It
provides trophic rankings and classifications for 145 Illinois water bodies
based on trophic indicator and multivariate trophic index estimates derived,
in part, from satellite-acquired data.  The information will be used by the
Illinois Environmental Protection Agency in one segment of its program to
meet the Federal mandate requiring the State to identify and classify,
according to trophic condition, all publicly-owned freshwater lakes (Public
Law 92-500, Section 314).  The report will also provide useful information to
other governmental agencies and organizations in the private sector that are
considering the use or are already using LANDSAT in a lacustrine trophic
classification program.  Further information on this subject can be obtained
from the Advanced Monitoring Systems Division.
                                               George B. Morgan
                                                   Director
                                  Environmental  Monitoring Systems Laboratory
                                                   Las Vegas
                                    m

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                                   SUMMARY
    This report describes the specific techniques utilized to generate a
satellite-based classification of 145 Illinois lakes and interprets and
disseminates the resultant products and ancillary information.  The report
represents one segment of an ongoing effort of the Illinois Environmental
Protection Agency (IEPA) to meet the mandates of Public Law 92-500, the
Federal Water Pollution Control Act Amendments of 1972 and Public Law 95-217,
the Clean Water Act of 1977.  Under Section 314-a of both laws, the
multifaceted legislation requires that each State prepare or establish, and
submit to the EPA Administrator for his approval:

   "(1)  an identification and classification according to eutrophic
    condition of all publicly-owned fresh water (sic) lakes in such State-;
    (2)  procedures, processes, and methods (including land use
    requirements), to control sources of pollution of such lakes; and
    (3)  methods and procedures in conjunction with appropriate Federal
    Agencies to restore the quality of such lakes."

    The State of Illinois has over 80,000 impoundments, of which 2,700 have
surface areas of 2.4 ha or more and are classified as lakes by the Illinois
Department of Conservation.  In light of the Federal mandate and the
magnitude of the task (Illinois has about 775 publicly owned lakes), the IEPA
elected to investigate new approaches to the lake classification problem.   To
receive serious consideration, an approach had to have the potential of being
cost effective and rapid and of yielding results of practical value.

    The approach described in this report employs a combination of
satellite-acquired and contact-sensed data along with multivariate
statistical techniques to classify a group of Illinois lakes.  The remote
sensor under consideration is the multispectral  scanner (MSS) on board NASA's
LANDSAT-1.

    LANDSAT MSS data acquired October 14-16, 1973, for 145 Illinois water
bodies were extracted from computer-compatible tapes (CCT's) using a digital
image-processing system at NASA's Jet Propulsion Laboratory (JPL).  Counts of
picture elements (pixels), the MSS's basic unit of spatial resolution, were
transformed to lake surface area estimates.  LANDSAT MSS digital  number (DN)
mean values for each spectral band were adjusted to a common date using
regression analysis.  The date-adjusted MSS data were then examined for the
existence of natural groups or clusters by applying a complete linkage
clustering algorithm to the four LANDSAT-derived spectral measurements made
on each lake.
                                     IV

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    Two multivariate trophic indices were developed through principal
component analyses of five trophic indicators (chlorophyll  a_,  inverse  of
Secchi depth, total phosphorus, conductivity, and total  organic  nitrogen)
measured in 1973 by the U.S. Environmental  Protection Agency's (EPA) National
Eutrophication Survey (NES).  Next, three sets of regression models were
developed from the contact-sensed and remotely sensed data  for 22  NES-sampled
lakes.  Four trophic indicators (chlorophyll  a^ inverse  of  Secchi  depth,
total organic nitrogen, and total phosphorus) and the two multivariate
indices were treated as dependent variables;  the four LANDSAT  MSS  bands
(including standardized and transformed versions) were utilized  as
independent variables.  The three sets of regression models were then
extended to the remaining 123 lakes in the study group.   Next^ the 145 lakes
were ranked by each of the four trophic indicators, a composite  trophic rank
parameter, and each of the two multivariate trophic indices using  the
LANDSAT-derived regression model estimates.  In addition, complete linkage
clustering algorithms were employed to delineate lake groups or  clusters
using the estimated values of four trophic indicators (Secchi  depth,
chlorophyll j*, total organic nitrogen, and total phosphorus) for the 145
lakes.  Interpretation and validation of the classification results were
augmented by a lake water quality data base acquired by  the State  of Illinois
in its 208 planning effort in 1977 and ancillary data from  other sources.

    The analyses of LANDSAT multispectral scanner (MSS)  and near-concurrent
contact-sensed data and ancillary information for 145 Illinois water bodies
indicate that lake clusters can be derived from LANDSAT  MSS raw  data and
MSS-estimated trophic indicator values.  Each cluster is distinctive and
identifiable in terms of general water quality, use impairment,  and  lake
characteristics.

    MSS data can also be used with contact-sensed data to develop  regression
models to provide relative estimates of Secchi depth, chlorophyll  a_, total
organic nitrogen, total phosphorus, and two multivariate trophic state
indices.  Although less accurate and precise than contact-sensed trophic
indicator values, the LANDSAT-derived parameter estimates can  be used  to
develop generalized rankings of Illinois lakes.  Regression models developed
from MSS and contact-sensed data for lakes with large parameter  value  ranges
and minimal contact-sensed data were more effective for the Illinois lakes
studied when spectral ranks rather than normalized spectral data were  used.
Parameter estimation models developed from raw MSS data  were least reliable.

    Lacustrine water quality and use impairment in Illinois are  significantly
impacted by suspended particulate matter.  Lake morphology  and hydraulic
factors affect the suspensoid load and general water characteristics.   The
best quality lakes studied were generally deep, for Illinois,  with long
retention periods (one year or more).  Water quality and general use
potential decreased for lakes with shorter retention times  and shallower
depths; generally the upper portions of reservoirs (areas of major stream
inflow) exhibit increased use impairment.  Although all  of  the study lakes
are affected by high levels of phosphorus, overall water quality is basically
influenced by suspended particle impacts on water transparency.

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    In other geographic areas, LANDSAT-derived lake surface area estimates
have exhibited excellent correspondence with area estimates derived from
concurrently acquired aerial photography; such imagery was not available for
use in this project.  The LANDSAT MSS provided surface area estimates
generally within 10 percent of values derived for the study lakes from State
of Illinois data files.

    The LANDSAT MSS is an economically viable tool for the acquisition of
data from all Illinois lakes and artificial  reservoirs of significant areal
extent (i.e., four or more hectares).  The extraction and processing of lake
MSS data is effectively accomplished, both costwise and timewise, through the
use of an image-processing system recently developed by the JPL for lake
classification purposes.

    By virtue of its repetitive coverage, synoptic overview, and ability to
generate permanent records amenable to automated image-processing techniques,
the LANDSAT MSS is attractive for purposes of environmental assessment and
monitoring.  In this study LANDSAT provided  a view of the past; it also
provides a monitoring strategy that is objective, uniform, frequent, resource
tolerant, and cost-effective for the future.  However, LANDSAT is not a
panacea; there are limitations and problems  associated with it.  A number of
problems were encountered during the study (e.g., a very limited selection of
cloud-free imagery, missing MSS internal  scene calibration data, atmospheric
effects).  Most of the problems encountered  during this study were
successfully addressed.  From the perspective of the State, this project was
highly successful, both in the insights that were gained while addressing
these problems and in the development of a high quality, comprehensive,
objective, short-term data base on Illinois  lakes.

    The following recommendations are made in light of the study results and
are consistent with reports on the assessment of lake problems and "clean
lakes" strategy completed under the Statewide 208 Water Management Planning
Program.  A routine lake monitoring and assessment program should be
developed by the IEPA and coordinated with various State, Federal, and local
agencies.  The program could be designed to  incorporate LANDSAT MSS data.
Completion of the multiyear data baseline for key Illinois lakes is
desirable.  Data collection could be coordinated with LANDSAT flyover.  Water
transparency and suspended particulates measurements should be emphasized.

    A statistically significant number of lakes should be sampled during
May-June and August-September to assess the  range of lake quality and user
impairments throughout the recreational  season.  Efforts should be made to
extrapolate the contact-sensed data collected from these lakes to other
significant Illinois lakes using LANDSAT technology.  Water samples collected
from a given lake and used in conjunction with LANDSAT data should be
integrated from the surface down to the maximum depth sensed by the MSS
(i.e., Secchi  depth).  The location and number of sampling sites should be
governed, in part, by the spectral  and spatial  characteristics of the
scanner.  Summer is generally the best sampling period for Illinois lakes
that are to serve as LANDSAT benchmark or reference water bodies.  The lakes
                                     VI

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selected for calibration or modeling purposes should be  representative  of the
range of lakes to be monitored and classified.   This may require more lakes,
and more types of lakes, than were used  in this  study.   The  Illinois EPA
should consider classifying the larger Illinois  reservoirs in  a mapping or
spatial context.  Many of the larger water bodies are not homogeneous,  and
they exhibit substantial differences in  water quality, both  in the  vertical
and horizontal dimensions.  The identification and location  of such water
types are of importance to lake management programs.  On large water bodies,
the MSS data should be calibrated against specific sample site information
acquired through contact sensing.  The use of LANDSAT MSS data as a means of
identifying land cover and land use practices, and the relationship of  land
use to lake characteristics, should be examined.

    When processing the LANDSAT MSS data, forward overlap as well as side
overlap lake data should be extracted; this will provide better  quality
control.  In addition, certain areas of the State should be  defined as
control points for the specific purpose of removing atmospheric  effects from
the MSS data.

    The data acquired during a future recreational high-use  season, the
summer of 1977, the 1973 three-season National Euthrophication Survey  (NES),
and the fall of 1973 by LANDSAT should be evaluated, along with  other
information, to determine seasonal and long-term stability of the lake
characteristics, to define, to identify, and to  map the  spatial-temporal
distributions of .lake quality, and to determine  representative sample
parameters, locations of sampling stations, and  times for routine monitoring
purposes.

    Based upon analyses of the lake data base, the Illinois  EPA  should
evaluate the lake assessment and the "clean lakes" strategy  developed  under
the 208 program.  Methods to control the sources of degradation  causing
fertility and sedimentation problems or management procedures to minimize
adverse impacts should be determined for the lakes.  Short-term  remedial
measures and long-range policies and programs should be  assessed to maximize
lake  life span and usability by the public.

    The applicability of using different multivariate approaches to ordinate
and classify  Illinois lentic water bodies should be further  examined.   For
example, it may be inappropriate to reduce the number of contact-sensed
parameters  (as was done in this study) prior to the implementation  of  a
segregation  procedure designed to separate those lakes with  sediment-related
turbidity problems from those with turbidity problems related primarily to
the presence  of algae.

    This project has successfully demonstrated that LANDSAT  MSS  data  can  be
used  to classify the lakes and artificial reservoirs of  Illinois.   It  has
served as the vehicle through which both Federal and State  scientists,
resource planners, and managers have developed a better understanding  of the
LANDSAT MSS's capabilities and limitations in the area of lacustrine  trophic
state assessment.  The  information relating to the technical aspects  of the
                                     vn

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project (e.g., digital image-processing techniques, scanner specifications,
multivariate statistical  techniques)  will  largely appeal  to the  scientist.
Resource managers and planners will  find the cluster diagrams, lake  rankings,
and tabular lake data (including ancillary information) to  be of practical
use.  Overall, the report should be of value in assisting the State  of
Illinois to meet its obligations under Public Law 92-500.
                                   viii

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                                  CONTENTS
Foreword 	   i i i
Summary 	    iv
Figures 	     x
Tabl es 	  xi i i
Abbreviations and Symbols 	   xiy
Acknowledgments 	  xvi i

1.  Introduction 	     1
         Background 	     1
         Objectives 	     2
2.  Conclusions 	     4
3.  Recommendations 	     6
4.  Geography and Lakes of Illinois 	     8
         Geography 	     8
         Lakes of Illinois 	    17
5.  Methodological Overview 	    27
         Optical properties of pure water and natural waters  	    28
         LANDSAT multispectral scanner 	    32
         Satellite sensing of Illinois lakes 	    38
6.  Methods	    49
         Design overview	    49
         Data acquisition 	    49
         Data processing 	    72
         Data analysis approach 	    103
7.  Results  and Discussion 	    116
         Water body surface area 	    116
         Trophic indicator and index estimation  	    120
         Cluster analysis	    133
         General discussion 	    164

References 	    172
Ap pendi x 	    183
                                     IX

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                                   FIGURES
Number

  1      NASA'S LANDSAT space observatory 	    3
  2      Physiographic provinces of Illinois 	    9
  3      Generalized surficial geology of Illinois 	   12
  4      Major soil orders in Illinois 	   14
  5      Principal streams of Illinois 	   15
  6      Hypothetical productivity growth-curve of a hydrosere 	   24
  7      Reflection characteristics of filtered and unfiltered water
           samples 	•	   31
  8      Schematic diagram of the LANDSAT-1 MSS scanning arrangement ...   33
  9      Generalized spectral reflectance curve for a single picture
           element (pixel) of a hypothetical lake	   34
 10      Generalized output of the LANDSAT MSS in response  to the
           spectral distribution illustrated in Figure 9 	   34
 11      Some components and interactions of light with a hypothetical
           lake and the atmosphere 	   36
 12      IR2 image of LANDSAT scene 1448-16023 	   39
 13      IR1 image of LANDSAT scene 1448-16023 	   40
 14      RED image of LANDSAT scene 1448-16023 	   41
 15      GRN image of LANDSAT scene 1448-16023 	   42
 16      Characteristic "fingerprints" of clear or distilled water,
           humic water, and algal-laden water	   44
 17      LANDSAT MSS spectral signatures and residual curves for
           three types of 1akes 	   45
 18      Range of MSS data for 145 Illinois lakes 	   47
 19      LANDSAT coverage pattern for the State of Illinois 	   51
 20      IR2 image of LANDSAT scene 1448-16023 	   52
 21      Enlarged  portion of LANDSAT IR2 print containing lakes and
           reservoirs found in scene 1448-16023 	   53
 22      IR2 image of LANDSAT scene 1448-16030 	   54
 23      IR2 image of LANDSAT scene 1448-16032 	   55
 24      IR2 image of LANDSAT scene 1448-16035 	   56
 25      IR2 image of LANDSAT scene 1449-16082 	   ,57
 26      IR2 image of LANDSAT scene 1449-16084 	   58
 27      IR2 image of LANDSAT scene 1449-16091 	   59
 28      IR2 image of LANDSAT scene 1449-16093 	   60
 29      IR2 image of LANDSAT scene 1450-16140 	   61
 30      IR2 image of LANDSAT scene 1450-16142 	   62
 31      Geographic  distribution  of the  Illinois water  bodies  	   73
 32      GRN,  RED,  IR1, and  IR2 images of a LANDSAT  scene 1448-16035
            subscene	   ?5

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                             FIGURES (Continued)

Number

 33      GRN, RED, IR1, and IR2 images of a LANDSAT scene 1448-16035
           subscene after the application of the  binary mask 	   76
 34      Interactive user console with video-display device and
           trackbal 1 	   78
 35      Crab Orchard Lake with default 50-by-50  element box	   80
 36      Crab Orchard Lake contained within correctly positioned box ...   80
 37      Crab Orchard Lake in binary form before  editing of extraneous
           water information 	   80
 38      Crab Orchard Lake in final, edited form  	   80
 39      Geometric interpretation of the water-detection algorithm 	   83
 40      LANDSAT MSS histograms of four bands of  Cedar Lake (serial
           number 55) 	   84
 41      IR2 concatenation of 33 Illinois water bodies extracted from
           LANDSAT scene 1448-16023 	   85
 42      IR2 concatenation of 12 Illinois water bodies extracted from
           LANDSAT scene 1448-16032 	   86
 43      IR2 concatenation of 20 Illinois water bodies extracted from
           LANDSAT scene 1448-16032 	   87
 44      IR2 concatenation of 27 Illinois water bodies extracted from
           LANDSAT scene 1448-16035 	   88
 45      IR2 concatenation of 20 Illinois water bodies extracted from
           LANDSAT scene 1449-16082 	   89
 46      IR2 concatenation of 35 Illinois water bodies extracted from
           LANDSAT scene 1449-16084 	   90
 47      IR2 concatenation of nine  Illinois water bodies extracted from
           LANDSAT scenes  1449-16093 and 1450-16140  	   91
 48      IR2 concatenation of 13 Illinois water bodies extracted from
           LANDSAT  scene 1450-16142 	   92
 49      Geometrical interpretation of the principal components  	   97
 50      Sequence  of procedures in  numerical classification 	  107
 51      Dichotomized  scheme depicting the salient properties of
           clusteri ng methods  	  109
 52      Geometric  aspects of Euclidian distance between two entities ..  Ill
 53      Geometric  and computational aspects of Euclidian distance
           between three entities  	  113
 54      Sequence  of procedures as  applied to the numerical
           classification  of Illinois water bodies  	  115
 55      LANDSAT-derived consecutive-day surface area estimates  for
           21  Illinois water bodies 	  118
 56      Comparison of October 14 and 16 LANDSAT-derived surface area
           estimates with  IEPA file values for 20 Illinois  water
           bodi es  	 121
 57      Comparison of October 15,  1973, LANDSAT-derived surface area
           estimates with  IEPA file values for 20  Illinois  water
           bodi es  	 122
 58      Dendrogram of 145 Illinois water bodies based  on complete
           linkage clustering  on four spectral attributes  	 140
                                     XI

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                             FIGURES (Continued)

Number

 59      Spectral index signature curves for six lake clusters 	 143
 60      Visual correlation between contact-sensed data and scaled
           MSS RED band data at the six-cluster level 	 146
 61      Light extinction relationship between MSS RED band index
           (percent) and Secchi depth measurements taken in 1977 	 147
 62      Total suspended solids relationship with Secchi depth 	 148
 63      Average annual runoff for Illinois in inches/square mile/
           year	 150
 64      Distribution of precipitation in centimeters for Illinois
           for the period October 11-14, 1973	 152

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                                   TABLES

Number

  1      Description of lake types in Illinois  	   19
  2      Optical  properties of pure water	   29
  3      LANDSAT MSS scenes ordered for Illinois  lake study  	   50
  4      Serial  list of Illinois water bodies 	   63
  5      Area!  statistics for example lakes 	   81
  6      MSS DN statistics for example lakes 	   81
  7      Regression models used to adjust  multispectral  scanner  data  ...   94
  8      R-mode Pearson product-moment correlation matrix of five
           trophic state indicators 	   98
  9      Normalized eigenvectors and eigenvalues  	   99
 10      R-mode Pearson product-moment correlation matrix of five
           trophic state indicators 	  100
 11      Normalized eigenvectors and eigenvalues  	  101
 12      Trophic state indices and rankings for 31 NES-sampled
           Illinois water bodies 	  102
 13      Some SAHN clustering methods 	  108
 14      Comparison of surface area estimates for 22 Illinois water 	  117
 15      Three sets of regression models for the  estimation  of
           trophic indicators and multivariate trophic state
           i ndi ces	  123
 16      Trophic indicator and multivariate trophic index observed,
           estimated, and residual values  for the Set Three  regression
           model s  	  129
 17      Comparison of the range of NES sample values with the 95 percent
           confidence limits of predicted values  	  131
 18      Summary statistics for Set Three (spectral rank) regression
           model s  	  132
 19      Rankings  of 145  Illinois lakes based on  Set Three models
           and ordered by name  	  134
 20      Composite ranking of 145 Illinois water bodies based on
           Set Three models and ordered by increasing trophic state	  138
 21      Index signatures for various water body types in Illinois 	  142
 22      Index signatures and general descriptions for six Illinois
           1 ake clusters  	  142
 23      Spectral  data and contact-sensed data for the clusters and
           subclusters developed using complete linkage clustering
           on four attributes (GRN, RED, IR1, IR2) 	  144
 24      Trophic classes developed from cluster analysis of trophic
           indicator estimates  from Set Three regression models 	  157
 25      Interpretation of clusters developed from Set Three regression
           model s  	  162
                                     xm

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                          ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS

  A-space
  C
  CHLA
  CCT
  CDC 3300
  COMNET

  COND
  DN
  EPA
  EROS

  FARINA

  GRN

  GRNIR1
  GRNIR2
  GRNRED
  GRNRK

  ha
  IBM 360
  I DOC
  I EPA
  IFOV
  IPL
  IR1

  IR1IR2

  IR1RK

  IR2
  IR2RK

  ISEC
  JPL
attribute space
Celsius
chlorophyll ji
computer-compatible tape
Control Data Corporation's Model  3300 digital  computer
Computer Network Corporation, 5185 MacArthur Blvd N.W.,
Washington, D.C.  20016
conductivity
digital number
U.S. Environmental Protection Agency
U.S. Geological Survey's Earth Resources Observation
System Data Center, Sioux Falls,  South Dakota
image-processing software program designed to mask out
corresponding spectral channels or bands
green band, that portion of the spectrum between 500 and
600 nanometers, also known as band 4
ratio of the green and near infrared-one band values
ratio of the green and near infrared-two band values
ratio of the green to red band values
lake rank based on the LANDSAT MSS-measured green
band value
hectare (1 x 104 square meters)
International Business Machines Model 360 digital computer
Illinois Department of Conservation
Illinois Environmental Protection Agency
instantaneous field of view
Image Processing Laboratory
near infrared-one band, that portion of the spectrum
between 700 and 800 nanometers, also called band 6
ratio of the near infrared-one and near infrared-two band
values
lake rank based on the LANDSAT MSS-measured near infrared-
one band value
near infrared-two band, that portion of the spectrum
between 800 and 1,100 nanometers, also called LANDSAT
band 7
lake rank based on the LANDSAT MSS-measured near
infrared-two value
inverse of Secchi depth transparency
Jet Propulsion Laboratory, a NASA facility in Pasadena,
California
                                      xiv

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LAKELOG
LANDSAT
LN

MSS
NASA
NES

nm
PCI
PC1F5
PC1Y5
pixel
r
R
R2
r-matrix

RAT100
RED

REDIR1
REDIR2
REDRK
RTSGRN

SAHN
SAS
SCS
SEC
S6RN
SIPS
Jet Propulsion Laboratory's interactive computer system
for the extraction and analysis of water body images
from LANDSAT and aircraft-acquired multispectral scanner
computer-compatible tapes
Land satellite; e.g., LANDSAT-1, LANDSAT-3; satellites in
NASA's Earth Resources Technology Satellite Program,
formerly known as ERTS
natural logarithm; e.g., LNSEC is the natural logarithm
transform of SEC
LANDSAT multispectral scanner
National Aeronautics and Space Administration
U.S. Environmental Protection Agency's National
Eutrophication Survey Program
nanometer, 1 x 10"^ meters
generalized form of a multivariate trophic state index
developed through principal component analysis of trophic
state indicators
multivariate trophic state index derived through
principal component analysis of the fall sampling
round values of five indicators:  Seechi depth,
chlorophyll <±, conductivity  total phosphorus, and
total organic nitrogen
multivariate trophic state index derived through
principal component analysis of the mean values for
three sampling rounds of five indicators:  Secchi
depth, chlorophyll a_, conductivity, total phosphorus,
and total organic nitrogen
picture element
Pearson product-moment correlation coefficient
multiple correlation coefficient
as used in regression, this is the square of the
multiple correlation coefficient, also called the
coefficient of multiple determination
product-moment correlation matrix whose elements are used
in principal components analysis
LANDSAT spectral ratio
red band, that portion of the spectrum between 600 and
700 nanometers
ratio of the red and near infrared-one band values
ratio of the red and near infrared-two band values
lake rank based on the LANDSAT MSS-measured red band value
square root transformation of standardized LANDSAT green
band values
sequential, agglomerative, hierarchic nonoverlapping
Statistical Analysis System; a set of computer programs
maintained by the SAS Institute, Inc., Post Office Box
10066, Raleigh, NC 27605
scene color standard
Secchi depth transparency
standardized form of the LANDSAT green band value
Statistical Interactive Programming System
                                   xv

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SIR1

SIR2

SQRTS6RN
SRED
STORE!

TON
TSS
TPHOS
VERTSL06


VSS
                   standardized form of  the  LANDSAT  near  infrared-one band
                   value
                   standardized form of  the  LANDSAT  near  infrared-two band
                   value
                   square root  of the LANDSAT  standardized  green band value
                   standardized form of  the  LANDSAT  red band  value
                   STOrage and  RETrieval;  EPA's  computer-based water quality
                   data bank
                   total  organic nitrogen
                   total  suspended solids
                   total  phosphorus
                   Jet Propulsion Laboratory's computer software program
                   that  performs digital image data  format  conversion
                   and geometric conversion
                   volatile suspended solids
SYMBOLS


  /\
  *
  **

  Ajk


  3-D
                 estimated value for a parameter; (e.g., TON:  regression-
                 derived estimate of total organic nitrogen)
                 multiplication, as used in computer programming
                 exponentiation, as used in computer programming
                 delta(jk), Euclidian distance between lake j and
                 lake k
                 delta squared, squared Euclidian distance
                 three-dimensional space
                                   xvi

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                               ACKNOWLEDGMENTS


    Sincere thanks are extended to Dr.  Robert E.  Frenkel  (Oregon State
University Department of Geography), Dr.  Richard  C. Swartz and
James A. Keniston (Newport Field Station, U.S. Environmental  Protection
Agency), and William C. Tiffany (Corvallis Environmental  Research Laboratory,
U.S. Environmental Protection Agency) for the logistical  and  instructional
support so vital  to the clustering and regression analysis aspects of this
project.

    It is a pleasure to acknowledge the assistance of Harold  Williamson,
Robert Eisenhart, Donna Wallace, and William Sandage (State of Illinois
Environmental Protection Agency) for their efforts in compiling and verifying
maps and topographic data.  LeVerne Hudson and Dan Goodwin provided Illinois
Environmental Protection Agency staff and administrative  support.  Dr. Robert
Haynes and Dr. Konanur G. Janardan (Sangamon State University) provided
technical advice.

    The assistance of John D. Addington,  Andree Y. Smith, and Albert L.
Mendoza (Jet Propulsion Laboratory Image  Processing Laboratory) in processing
the LANDSAT computer-compatible tapes and developing the  interactive image
processing system is gratefully acknowledged.
                                    xvn

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                                  SECTION  1

                                INTRODUCTION

BACKGROUND

    Lakes and reservoirs have long been recognized  as  valuable  resources
serving as focal  points for many types  of  recreational  activity such as
fishing, swimming, skiing,  and boating. They also  help to  meet the water
demands of municipalities,  thermal-electric  plants, commercial  navigation,
and irrigation projects. Many inland water  bodies, particularly those  in
pristine condition, are valued for their aesthetic  qualities.   However, they
also provide convenient places to dump  the organic  and inorganic wastes of
society.  Some are being drained to provide  additional  farmland; still  others
are encroached upon through landfill  schemes.  Many water bodies,
particularly those in agricultural areas and in or  near population centers,
are exhibiting the secondary effects of man-induced eutrophication  (e.g.,
nuisance algal blooms).

    Eutrophication — the process of nutrient enrichment of water — occurs
both naturally and as a consequence of  man's activities.  Many  of man's
approaches to the disposition of municipal sewage and  industrial wastes,
along with his land-use practices, impose  large nutrient loads  on lakes and
reservoirs.  This enrichment process may result in  algal blooms and other
secondary effects of eutrophication and thereby make these  water bodies less
attractive to users.  In Illinois, significant impacts on lake  water quality
and user preference are frequently associated with  sediment pollution  in  the
water bodies.

    The rational  management of a State's or  the Nation's inland lentic
resources requires, as an initial step, that an inventory be made that
focuses on geographic, morphometric, biotic, and physiochemical factors
characterizing these waters.  Thus, in  1972, the U.S.  Congress, responding  to
citizens and organizations concerned with  the decline  in the quality of the
Nation's water resources, passed Public Law  92-500, the Federal Water
Pollution Control Act Amendments of 1972.  The legislation  requires that  each
State identify and classify, according  to trophic condition, all publicly
owned freshwater lakes under its jurisdiction (Sections 106 and 314).

    For States with large numbers of lakes and artificial reservoirs, the
mandated task is one of major proportions.  The State of Illinois,  for
example, has over 80,000 impoundments  (2,700 of which  have surface  areas  of
2.4 hectares or more and are classified as lakes by the Illinois Department
of Conservation), and collecting the data  necessary for identification  and
classification entails a project of sizable  logistical and monetary
proportions.  The fielding of boat-equipped  crews is hindered by budgetary,

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manpower, and time constraints.  The use of helicopter-borne field crews,
although attractive, is beyond the financial budget of the State.

    The aforementioned circumstances dictate that consideration be extended
to other than traditional approaches when attempting to trophically classify
large numbers of water bodies.  Any such approach should be cost effective
and rapid and should yield results having practical value.  One such approach
employs data collected by satellite-borne sensors to develop trophic
classifications of water bodies.

    On July 23, 1972, the National Aeronautics and Space Administration
 (NASA) inserted a satellite called LANDSAT-1 (Figure 1) into a
 sun-synchronous near-polar orbit to monitor the earth's resources.  A
companion satellite, LANDSAT-2, was successfully launched January 22, 1975.
The tandem satellites provide repetitive coverage of nearly every point on
the earth's surface on a 9-day basis.  A third satellite, LANDSAT-C and now
 known as LANDSAT-3, was successfully launched March 5, 1978.  The operation
of the LANDSAT-1 multispectral scanner ceased on January 6, 1978.  Several
types of instrumentation are carried by the satellites including an imaging
multispectral scanner (MSS).  Numerous investigations (e.g., Blackwell and
Boland 1979, Yarger and McCauley 1975, Moore and Haertel 1975, Strong 1973,
 Fisher and Scarpace 1975, Boland and Blackwell 1975, Boland and Blackwell
 1978, Boland 1976, Rogers et al. 1976, Rogers 1977) have demonstrated the
 potential capabilities of the LANDSAT MSS for lake monitoring and
 classification when used in combination with contact-sensed data.

OBJECTIVES

    The basic objective of this project is to classify Illinois lakes and
 reservoirs as to their trophic status and other characteristics, using an
 approach combining contact-sensed and remotely sensed (i.e., LANDSAT MSS)
data.  Classification, in a restricted sense, is the procedure of placing n
objects or p attributes into groups as defined by certain decision criteria.
A broader definition of classification includes the process of ordination and
its resultant products.  In this report, classification is used in its less
restrictive sense.

    Specific project objectives are to:

         1.  Develop rankings for some 150 Illinois lakes and
             artificial reservoirs based on estimated magnitudes of
             the following trophic indicators:

             a.  Secchi disc transparency (SEC);
             b.  Chlorophyll i (CHLA);
             c.  Total organic nitrogen (TON); and
             d.  Total phosphorus (TPHOS).

         2.  Develop lake rankings based on multivariate trophic indices.
         3.  Compile lake surface area estimates.
         4.  Identify lake trophic classes and their quality.

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    SOLAR ARRAY
  ORBIT ADJUST TANK
DATA COLLECTION ANTENNA
                                      ATTITUDE CONTROL SUBSYSTEM
                       RETURN BEAM
                    VIDICON CAMERAS (3)
                                             WIDEBAND
                                             RECORDER
                                             ELECTRONICS
         WIDEBAND ANTENNA



        ATTITUDE MEASUREMENT SENSOR

     MULTISPECTRAL  SCANNER

S BAND ANTENNA
    Figure 1.   NASA's LANDSAT space observatory  (NASA 1972).
       Develop  procedures to  classify  Illinois water  bodies into  groups
       with similar qualities and to rank  the groups  in order of
       quality.
       Identify  the parameters that most significantly  affect lake
       quality and use.

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                                  SECTION 2

                                 CONCLUSIONS


    The analyses of LANDSAT multispectral scanner (MSS)  and  near-concurrent
contact-sensed data, and ancillary information,  for 145  Illinois water  bodies
indicate that:

    1.   Lake clusters can be derived from LANDSAT MSS raw data and  MSS-
         estimated trophic indicator values;  the clusters compare well  with
         near-concurrent contact-sensed  data  and ancillary information. The
         application of an unsupervised  clustering algorithm to raw  MSS data
         resulted in the establishment of distinctive lake clusters  and
         subclusters, eaclTidentifiable  in terms of general  water quality,
         use impairment, and lake characteristics.

    2.   LANDSAT MSS data can be used with contact-sensed data to develop
         regression models that provide  relative estimates of Secchi  depth,
         chlorophyll £, total organic nitrogen,  total phosphorus, and two
         multivariate trophic state indices.   Though less accurate and
         precise than contact-sensed trophic  indicator values, the LANDSAT-
         deriyed parameter estimates can be used to develop  generalized
         rankings of Illinois lakes.

    3.   Regression models developed from MSS and contact-sensed data for
         lakes with large parameter value ranges and minimal  contact-sensed
         data were more effective for the Illinois lakes studied when
         spectral ranks rather than normalized spectral  data were used.
         Parameter estimation models obtained from raw MSS data were least
         reliable.

    4.   LANDSAT spectral index signatures developed from raw MSS data
         provide an acceptable characterization of general lake quality and
         use impairment and can be used  to establish an  objective assessment
         baseline for lake ordination and inventory purposes.

    5.   The LANDSAT MSS provided surface area estimates generally within 10
         percent of values derived from  State of Illinois data files
         for the study lakes.  In other  geographic areas, LANDSAT-derived
         lake surface area estimates have exhibited excellent correspondence
         with area estimates derived from concurrently acquired aerial
         photography; such imagery was not available for use in this project.

    6.   The LANDSAT MSS is an economically  viable tool  for  the acquisition,
         within three days and at a spatial  resolution of  about 0.64

                                     4

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      hectares, of data from all  Illinois  lakes and  artificial  reservoirs
      of significant areal  extent (i.e., four  or more  hectares).

 7.   The extraction and processing of lake MSS data is  effectively
      accomplished, with respect  to both cost  and  time,  through the
      use of LAKELOC, a recently  developed image-processing  system.

 8.   Lacustrine water quality and use impairment  in Illinois  is
      significantly impacted by suspended  particulate  matter.   Lake
      morphology and hydraulic factors affect  the  suspensoid load  and
      general  water characteristics.

 9.   The best quality lakes studied  were  generally  deep,  for  Illinois,
      with long retention periods (one year or more).  Water quality and
      general  use potential  decreased for  shorter  retention-time lakes
      with shallower depths; generally the upper portions  of reservoirs
      (areas of major stream inflow)  exhibit increased use impairment.

10.   Although all  of the study lakes are  affected by  high levels  of
      phosphorus, overall water quality is basically influenced by
      the effect of suspended particles on water transparency.

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                                  SECTION 3

                               RECOMMENDATIONS
    Most of the problems encountered during this  study  were  successfully
addressed.  From the perspective of the State,  this  project  was  highly
successful, both in the insights that were gained while addressing these
problems and in the development of a high  quality, comprehensive, objective,
short-term data base on Illinois lakes.  The following  recommendations are
made in light of the study results and are consistent with reports on the
assessment of lake problems and "clean lakes" strategy  completed under the
Statewide 208 Water Management Planning  Program (IEPA 1978a,  IEPA 1978b).

    1.   A routine lake monitoring and assessment program should be developed
         by the Illinois Environmental  Protection Agency (IEPA) and
         coordinated with various State, Federal, and local  agencies.  The
         program could be designed to incorporate LANDSAT multispectral
         scanner (MSS) data.

    2.   Completion of the multiyear data  baseline for  key Illinois lakes
         is desirable.  A significant number of lakes should  be sampled
         during May-June and August-September to  assess the  range of lake
         quality and user impairments throughout  the recreational season.
         Data collection could be coordinated with LANDSAT flyover.  Water
         transparency and suspended particulates  measurements should be
         emphasized.

    3.   Efforts should be made to extrapolate  the contact-sensed data
         described in the second recommendation to significant Illinois
         lakes using LANDSAT technology.

    4.   The data acquired during a future recreational high-use season, the
         summer of 1977, the 1973 three-season  National Eutrophication Survey
         (NES), and the fall of 1973 by LANDSAT should  be evaluated, along
         with other information, to determine seasonal  and long-term
         stability of the lake characteristics; to define, identify, and map
         the spatial-temporal  distributions of  lake  quality,  and to
         determine representative sample parameters, locations of sampling
         stations, and times for routine monitoring  purposes.

    5.    Based upon analyses of the lake data base,  the Illinois EPA should
         evaluate the lake assessment and  the "clean lakes"  strategy
         developed under the 208 program.   Methods to control the source(s)
         of degradation causing fertility  and sedimentation  problems or

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      management procedures to minimize  adverse impacts  should  be
      determined for the lakes.  Short-term remedial  measures and
      long-range policies and programs should  be assessed to maximize
      lake lifespan and usability by the public.

 6.   Water samples collected from a given  lake and  used in support
      of LANDSAT should be integrated from  the surface down to  the maximum
      depth sensed by the MSS (i.e., Secchi  depth).   The location and
      number of sampling sites should be governed, in part, by  the
      spectral  and spatial characteristics  of  the scanner.  Summer is
      generally the best sampling period for Illinois lakes that are to
      serve as  LANDSAT benchmark or reference  water  bodies.

 7.   The lakes selected for calibration or modeling puposes should be
      representative of the range of lakes  to  be monitored and  classified.
      This may  require more lakes, and additional  types  of lakes, than
      were used in this study.

 8.   The Illinois EPA should consider classifying the larger Illinois
      reservoirs in a mapping or spatial  context.  Many  of the  larger
      water bodies are not homogeneous,  and they exhibit substantial
      differences in water quality, both in the vertical and horizontal
      dimensions.  The identification and location of such water types is
      of importance to lake management programs.  On large water bodies,
      the MSS data should be calibrated  against specific sample site
      information acquired through contact  sensing.

 9.   The use of LANDSAT MSS data as a means of identifying land cover and
      land-use  practices and their relationship to lake  characteristics
      should be examined.

10.   When processing the LANDSAT MSS data,  forward  overlap as  well as
      side overlap lake data should be extracted; this will provide better
      quality control.

11.   Certain areas of the State should  be  defined as control points for
      the specific purpose of removing atmospheric effects from the MSS
      data.

12.   The applicability of using different  multivariate  approaches to
      ordinate  and classify Illinois lentic  water bodies should be further
      examined.  For example, it may be  inappropriate to reduce the
      number of contact-sensed parameters (as  was done in this  study)
      prior to  the implementation of a segregation procedure designed
      to separate those lakes with sediment-related  turbidity problems
      from those with turbidity problems  related primarily to the
      presence  of algae.

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                                  SECTION 4

                       GEOGRAPHY AND LAKES OF ILLINOIS
GEOGRAPHY
    An overview of Illinois physical geography is provided in this
subsection.  More detailed descriptions can be found elsewhere (e.g.,
Strahler 1969, Fenneman 1938, Thornbury 1965).  The information presented in
the following subsections draws heavily from the work of the State of
Illinois Environmental Protection Agency (IEPA 1976).

Physiography and Geology

    Illinois is largely a low prairie plain with an average elevation  of
approximately 193 meters above sea level (Kofoid 1903 as cited by Gunning
1966).  With an elevation of 377 meters, Charles Mound, located in the
northwestern corner of the State near the Illinois-Wisconsin border, is the
highest topographic point (Rand McNallv 1971).  [Gunning (1966) reports an
elevation of 383 meters.  Bethel (1969) records 378 meters as the elevation
of Charles Mound.]  The lowest point in the State is at Cairo where the
low-water mark of the Ohio River has been measured as 82 meters (Gunning
1966).  Local relief, the difference in elevation between lowest and highest
topographic points in adjacent locations, is typically less than 60 meters
(IEPA 1976).  Fenneman (1928) has divided the State into four physiographic
provinces (Figure 2).  Leighton et al. (1948) have further subdivided
Illinois into eight physiographic sections using the following criteria:
bedrock topography, extent of the several glaciations, glacial morphology
differences, age differences of the uppermost drift, height of the glacial
plain above the main lines of drainage, glaciofluvial aggradation of basin
areas, and glaciolacustrine action.

    More than 90 percent of Illinois is located in the Central Lowland
province.  With the exception of the Wisconsin Driftless section located in
extreme northwestern Illinois (Jo Daviess and Carroll Counties), all of the
province has been glaciated.  The Ozark Plateaus, Interior Low Plateaus, and
Coastal Plain province account for the remainder of Illinois.

    Three sections constitute the bulk of the Central Lowland province in
Illinois:  the Great Lakes section, the Wisconsin Driftless section, and the
Till  Plains section.  The Great Lakes section, located in northeastern
Illinois, is largely dominated by an area called the Wheaton morainal
country.  Wedged between the morainic area and Lake Michigan is the Chicago
lake  plain.  The lake plain is characterized by a flat surface underlain
largely by till  (a heterogeneous mixture of rock fragments ranging in  size

                                     8

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                                         Till Plains Section
                          CWttconsirf/T
                           >.Driftlesi/
                         ^  \SectionV                .
                          ^^ V	IL —Rock River
 Great Lake
£	1 Section
                                                              Morainal"TCnicago
                                                            V^ountrv
              Water body not included in
              L rankings and dendrograms because
              of faulty or missing MSS data


              NES - sampled water body used in
              | regression model development and
              included in rankings and dendrogram*


»              Water body included in rankings and
              dendrograms
            Ozark Plateaus Province


            Interior Low Plateaus Province


            Coiiitl Pl»in Province


          ^ Central Lowland Prowmce
Figure 2.   Physiographic  provinces  of  Illinois.   The water bodies marked  on
              the map  were proposed for inclusion  in this  project.   Figure
              adapted  from Illinois State Geological Survey  map  (IEPA  1976).

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from clay to boulders and associated with glaciers) and having a gentle slope
toward Lake Michigan.  Postglacial erosion has been of a relatively small
magnitude and is most evident in the valleys along the Fox and Des Plaines
Rivers (IEPA 1976).

    The topography of the Wisconsin Driftless section (Figure 2) reflects the
physical-chemical character of the underlying rock and is a consequence of
the apparent lack of glacial activity in the area.  Dendritic drainage
systems, tributary to the Mississippi River, dissect the section.  A
substantial amount of drainage occurs through small caves and solution
channels.   However, features associated with karst topography are not readily
evident.

    Approximately 80 percent of the State is classified as belonging to the
Till  Plains section, an  area dominated by broad till plains with poorly
developed  drainage systems.  The western and southern limits of the
Bloomington ridged plain effectively define the boundary separating the older
 Illinoian  deposits from  those Wisconsin!"an in age.  Physiographic contrasts
 (e.g., degree  of drainage  integration, extent of  soil development, erosional
modification  of the topography) have developed because of these age
differences.

     A fourth  section of  the Central Lowland province, the Dissected Till
 Plains section, is found in three western Illinois counties, Hancock, Adams,
 and Pike.   In  this section glaciation occurred in an earlier stage, the
 Kansan, and this accounts  for the submaturely dissected landscape (Fenneman
 1938).  The longer time  element has allowed the Dissected Till Plains section
 to reach a more advanced point in the postglacial erosion cycle than the Till
 Plains section to the east  (Fenneman 1938).

     The Ozark  Plateaus province is represented in Illinois by two sections,
 the Lincoln Hills section  and the Salem Plateau section.  Both sections are
 found along the southwestern boundry of the State (Figure 2).  The sole
 representative of the  Interior Low Plateaus province in Illinois is the
Shawnee Hills  section  (also known as the Shawnee  section) found in the
southern portion of the  State.  The southern tip  of Illinois lies in the
Mississippi Alluvial Plain  section  (commonly called the Mississippi
Embayment)  of  the Coastal  Plain province.  Detailed descriptions of these
relatively minor components of Illinois physiography can be found in Fenneman
 (1938) and Thornbury  (1965).

    The geologic units of  Illinois are classified into four major divisions:
1) Precambrian basement  rock; 2) consolidated sedimentary bedrock; 3) a
variably thick blanket of  glacial drift; and 4) a mantle of loess.  The
Precambrian basement rock  lies hidden, covered by some 600 to more than
3,960 meters of sedimentary strata.  Borings, both  in  Illinois and
immediately outside the  State's border, have yielded plutonic and volcanic
rocks of granitic or closely related composition  (Bradbury and Atherton
1965).

    Consolidated sedimentary rocks, ranging in age  from Cambrian through
Tertiary, are  found throughout the State.  Extensive exposures of these  rocks

                                     10

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are limited to extreme northwestern Illinois and  to the southwestern  and
southern part of the State in areas along the Mississippi  and  Ohio  Rivers
falling outside the glacial  margin.  Scattered bedrock  outcrops,  usually
limited to areas of high bedrock or the walls of  the more  deeply  cut  valleys,
are found within the glaciated region.   The Ordovician  and Silurian rocks  are
largely dolomite.  The Mississippian rocks are dominated by limestone, and
the Pennsylvanian rocks by shale and sandstone.  Illinois  is noted  for its
large deposits of mineable coal, which  are found  in the Pennsylvanian strata.

    Approximately 90 percent of Illinois is blanketed by glacial  deposits
consisting of both stratified drift and till deposited  during  each  of the
four major glacial stages (Figure 3).  Drift of Nebraskan  age, the  first
glacial stage, is known in Illinois only from subsurface deposits in  the
western part of the State.  The Kansan  glaciation covered  most of the State,
but subsequent glacial stages have restricted exposed Kansan tills  to a small
area in western Illinois, the Dissected Till Plains section.  The third
glaciaticn, the Illinoian, marked the southern most incursion  of  the
continental ice sheet in North America.  The ice  extended  to within
33 kilometers of the Mississippi Embayment in southernmost Illinois,  laying
down an extensive blanket of drift over much of the State.  The last
glaciation, the Wisconsinian, is recognized as a  major  factor in  molding the
character of the modern landscape (Flemal 1972).   The Wisconsinian  deposits,
largely confined to northeastern Illinois, have not been exposed  to
weathering as long as the older Illinoian deposits and, therefore,  exhibit
marked soil differences when compared to II linoian-derived soils.

    Willman and Frye (1970)  report that as much as half of the material
comprising the tills of Illinois has been transported less than
160 kilometers from its bedrock source.  The glacial  drift ranges in
thickness from zero to about 180 meters, with the average  being about
30 meters.  Relatively thin layers of drift are found in western  and  southern
Illinois.  The northeastern  quarter of  the State  is mantled by a  thick drift
deposit.  As might be expected, extremely thick drifts  blanket the  major
bedrock valleys.

    Much of Illinois is covered by loess, a silty windblown deposit that
consists chiefly of dust from dry glacial river valley  floors. It  is
thickest east of the valleys because of the prevailing  westerly winds.  It
becomes progressively thinner as the distance from the  source  increases.
Loess, the most extensive parent material of Illinois soils, varies in
average thickness from about 2 to 6 meters in western Illinois to 0.5 to
1.5 meters in the eastern part of the State.  The Army  Corps of Engineers
(1969) reports it as being the major constituent  of the suspended sediment
transported in Illinois streams.  The State's loess-covered plains  are widely
recognized for their agricultural  productivity.

Soils

    The major parent materials forming  Illinois soils are  loess,  outwash,
till, and alluvium.  Bedrock and accumulations of organic  material  (e.g.,
peat) are of relatively minor importance.  The following is a  reiteration  of
lEPA's (1976) description of Illinois soils, which in turn is  based largely
on the work of Fehrenbacher et al. (1967).

                                     11

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                        SURFICIAL
                        GEOLOGY
               /Loess thickness (fi).
            -,\*   Hochures point m
           r      direction  of  thinning

                     Loess-Corertft Areas

                ] Giociol drift (Wisconsmon), kvgely
                  till, coicoreous to top except
                  where loess  is less thon 4 ft
                  thick ond leoched

                 Gtociol drift (Illtnoion), momly till, upper 5 to
           ^~~~^  10 ft generally noncolcoreous

               S GkKiol drift (Kanson). largely till, upper 15 to
                  30 ft generally noncolcareous

           F!'ffi''j' j Sand,gravel, or silt (Cretaceous-Tertiary)

           !	I Bedrock (Paleozoic), various consolidated rock!

                     Loess Absent or Very Thin
              -• ] Alluvium, river and stream deposits — silt, sat
            	  (Cahokia Alluvium)

                | Lake deposits-silt, cloy, sand (Equality Formation)

                j Sand dunes-wind-deposited sand (Parkland Sand)

                I Glacial outwash - major outwosh plains and terraces  of
                  sond ond grovel (Henry Formation)
Figure  3.    Generalized  surficial  geology of  Illinois.    In  uneroded areas  the
                loess thins  from  25 to  100  feet thick  in  the  bluffs  of  the  major
                valleys  to 1  to 2 feet  in  areas farthest  from the  valleys.
                (Figure  courtesy  of the  Illinois  State Geological  Survey.)

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    Of the 10 major soil  orders  comprising the 7th Approximation (Soil Survey
Staff 1960) -- Aridisols, Vertisols,  Spodosols,  Ultisols, Oxisols, Histosols,
Inceptisols, Mollisols,  Alfisols,  Entisols -- the latter three dominate
Illinois (Figure 4).

    Histosols occur mainly in extreme northeastern  Illinois.  They are
organic soils (peats and mucks)  that  are distinguishable from those of the
other nine orders by gross composition differences,  most notably their high
organic content of 20 percent or better (Simonson 1962).  Histosols are wet
soils, generally requiring drainage when used for most  agricultural purposes.

    Alfisols predominate in southern  Illinois.   A light color is generally
associated with the surface layer; if the color  is  dark, the surface  layer is
less than 25 centimeters thick.  In either case  the surface layer has an
organic content of less than one percent throughout its total thickness.
Another characteristic of Alfisols is a recognizable B  horizon of clay
accumulation.

    Mollisols cover about 49 percent  of the State with  most occurring in
central and northern Illinois.  These are mineral  soils possessing what is
called a mollic epipedon.  This darkened surface layer  has  an organic content
of more than one percent, is high in  base saturation, and  is friable.

      Inceptisols are usually found in small  or narrow areas and  are  included
with Mollisols in the bottom lands and with the Alfisols  in the  uplands.
Although  lacking the mollic epipedon of the Mollisols and  the B  horizon of
clay accumulation associated with Alfisols, Inceptisols do have  recognizable
horizons  or show evidence of the beginning of horizon development.

    Entisols are mineral  soils whose profiles contain few and  faint  horizons.
They  cover an estimated  1.5 percent  of  Illinois, occurring along streams  and
in  very sandy areas.  Entisols are known to form in regoliths  consisting  of
highly resistant minerals, in areas  where the accumulation of  surface
materials keeps pace with horizon differentiation, and  in localities where
the erosion  rate keeps  up with  horizon  differentiation (Simonson 1962).

Climate

    According to the Koppen-Geiger system of climate classification, the
northern  third  of  Illinois is classified as humid continental;  the remainder
of  the State is  placed  in the humid  subtropical category (Strahler 1969).
The State's geographic  location results in great variations in temperature
and precipitation  over  the course of a  gjven year.  The mean annual
temperature is  about 8  degrees  Celsius  ( C) in  the north, increasing to
15  C  in the south.   Normally, January  is theocoldest month with a mean
temperature of  about -6 C in the  north  and 2 C  in the  south.  July,
usually the hottest month, exhibits  a  similar north to south temperature
trend with the  mean values being  about  23 C and 27 C,  respectively.  Mean
 annual  precipitation also displays a north-to-south trend -- 80 centimeters
and 120 centimeters, respectively.   Except for  a small  area in the southern
 part  of Illinois,  the  period of maximum precipitation  occurs during  the
                                      13

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                  MOLLISOL ORDER


                  ALFISOl ORDER


                  ENTISOL ORDER
Figure 4.  Major soil orders  in  Illinois  (from Fehrenbacher et al.  1967).
           Of the 10 soil orders  in  the 7th Approximation,  five —
           Mollisols, Alfisols,  Entisols,  Histosols, and Inceptisols — are
           important in  Illinois.  The Inceptisols and Histosols cover rela-
           tively small  areas  and  are  not  shown in the above figure.

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growing season.   In general,  northern  Illinois  receives a larger percentage
of its total  precipitation  during  the  growing season than does the southern
part.  This is important because  it  tends  to make the  lesser precipitation in
the north as  effective for  growing crops as the greater annual quantities in
southern Illinois (Page 1949).

Drainage

    Three major rivers border Illinois:  the Mississippi on the west, the
Ohio on the south,  and the  Wabash  on the southeast  (Figure 5).  Large streams
that provide  the internal  drainage of  the  State include the Illinois, Rock,
Kaskaskia, Big Muddy, Embarras, and  Little Wabash Rivers.  The Illinois
River, the largest  stream within  Illinois, drains the  State in a generally
southwesterly direction.  The Rock River,  the
State, drains the northwestern portion of
adjacent southern Wisconsin.   Three  major
    second largest  stream in  the
Illinois as well  as parts of
sub basins -- the Pecatonica,
Kishwaukee, and Green River Basins -- comprise  the  Rock  River Basin.
       Figure 5.  Principal  streams of Illinois (from O'Donnell  1935),

                                     15

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    The Kaskaskia and Big Muddy Rivers join the Mississippi River in
southwestern Illinois.  The Kaskaskia, the larger of the two, originates in
east-central Illinois.  The Big Muddy River is confined to the southern
portion of the State.  Four Illinois streams, the Embarras, Little Wabash,
Vermilion-Wabash, and Saline, all flow in generally southeasterly courses and
feed the Ohio and Wabash Rivers.

    Approximately 81 percent of  Illinois is drained directly to the
Mississippi River by means of southwest flowing streams (e.g., Illinois and
Rock Rivers).  Almost 19 percent is drained indirectly to the Mississippi
River  by way of the Ohio and Wabash Rivers.  Less than 0.1 .percent of the
State's area is drained into the Great Lakes system (McCarthy 1972).

Land Use

     Illinois covers an area of approximately 146,076 square kilometers
 (14,607,600 hectares), not including the 3,950 square kilometers of Lake
Michigan.   The actual land area has been calculated as 144,872 square
 kilometers  (Bethel 1969).  Eighty-three percent of Illinois human population
 is  classified as urban with about 80 percent being clustered into 10 Standard
Metropolitan Statistical Areas (SMSA).

     Agriculture is the dominant land use in Illinois, with tilled crops
dominating.  Cropland distribution is more dense in the central and northern
 parts  of the State than in the western and southern parts. The Illinois
 Cooperative Crop Reporting Service (1974) found the major crop to be
 soybeans, followed in order by corn, wheat, and hay.  IEPA (1976) report that
 about  74 percent of the inventoried land is devoted to tilled crops; cropland
 increased from 96,620 square kilometers in the 1958 inventory to 98,745
 square kilometers in 1967. Inventoried land is defined as the total surface
area of the State minus Federally owned land, water areas, and land used for
urban  purposes.  The inventory was conducted by the Illinois Inventory of
Soil and Water Conservation Needs to determine the use and condition of
privately owned rural land in Illinois.  Inventory participants included the
United States Department of Agriculture and various State agencies.

     Inventoried woodlands and forests cover approximately 11 percent of
Illinois, with most being classified commercial.  The noncommercial forests
serve  very  important recreational and conservation functions.  Forest lands
have declined from 1958 to 1967 as indicated by the area estimates of 15,783
and 14,569  square kilometers, respectively.

    The third largest use of rural land is grazing.  Approximately 10 percent
of the inventoried land is used to pasture livestock.  A slight expansion in
pasturage has been noted, with 13,395 square kilometers reported for 1958 and
13,557 square kilometers for 1967.  Grazing lands, generally confined to the
more hilly  regions, are most dense in northwestern, western, and southern
Illinois.

    Another land-use category, "other land" (rural land that is not used as
cropland, forest land, or pastureland), has declined from 7,284 square
kilometers in 1958 to 6,070 square kilometers in 1967.  Some "other land" is

                                     16

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used for recreation and wildlife.   In  some localities the quarrying of sand
and gravel  and the mining  of  coal  are  of major importance.  The extraction of
sand and gravel  occurs mainly near major urban centers (e.g., Chicago).
Illinois, the fourth-ranked State  in coal production (IEPA 1976), has large
coal deposits in its bedrock  of  Pennsylvanian age.  Coal strip mines are
found along the outcrop margins  of Pennsylvanian strata.  Elsewhere, the
depth of the coal  from the surface necessitates the use of underground
mi ni ng.

LAKES OF ILLINOIS

    There is far from universal  agreement as to what constitutes a lake.
Veatch and Humphrys (1966) suggested that to give  the word "lake" a precise,
limited meaning would probably be  an exercise in futility because the word
has been in use for a long time  in a variety of applications.  The word is
used as a synonym for pond,  reservoir, and sea.  It has been applied to
bodies of fresh water and  saline water, to standing water and widenings in
rivers, to bodies of water measuring less than a hectare and to those gauged
in  hundreds of thousands of hectares,  to  naturally occurring water bodies and
manmade reservoirs, to water-filled or partially filled basins, and to basins
void of water.  "Lake" is generally more  prestigious than other common  names
(e.g., pond, slough, reservoir)  and is preferred by  promoters of water-based
tourist and recreational businesses and commercial developers of shoreline
property (Veatch and Humphrys 1966).  Nevertheless,  numerous attempts have
been made to define and delimit  the members  of lentic  series (i.e., lake,
pond, marsh, and their intergrades).

    Fore! defined a lake as a body of standing water occupying a basin  and
lacking continuity with the sea, and a pond  as  a  lake  of  slight depth  (Welch
1952).  Welch defined a lake as  a "... body  of  standing water completely
isolated from the sea and having an area of  open,  relatively deep  water
sufficiently large to produce somewhere on its  periphery  a barren, wave-swept
shore."  He employed the term "pond"  "...  for that class  of very small, very
shallow bodies of standing water  in which quiet  water  and  extensive occupancy
by  higher  aquatic plants are common characteristics  ..."  and suggested  that
all larger bodies of standing water be referred  to as  lakes.   Zumberge  (1952)
defined  a  lake as an  inland basin filled with water.   Harding  (1942)
described  lakes as  "... bodies of water filling  depressions  in the earth's
surface."  The  Illinois Department of Conservation (IDOC)  uses a  size
criterion  (2.4 hectare or larger  in surface  area)  to define  lake.   In  this
report no  deliberate  effort will  be made to  carefully distinguish  a  lake  from
another  lentic body on the basis of a definition.   We are using the term  lake
 in its broadest sense.  For example an artificial  reservoir  may be called a
lake  or, at  times,  a  water body.

     The Illinois  Surface  Water  Inventory prepared by the  State of  Illinois
Department of Conservation (1972)  reported that the State had  2,706  lakes
 (2.4  ha or larger in  surface area) and 73,595 ponds (less than 2.4 ha  in
 surface area)  in  1972.  Of the  2,706  lakes,  only  709 were natural  --  either
glacial  lakes in  the  north or flood plain or oxbow lakes  along  the major
 rivers.   The remaining  1,997 were ma made (IDOC 1972, Gunning  1966,  and
                                      17

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Bennett 1960).  An inventory of Illinois lakes (IEPA 1975)  reveals a  total  of
773 publicly owned freshwater lakes, with 273 lakes having  surface areas  in
excess of 8 hectares.  Excluding the portion of Lake Michigan within  the
Illinois boundary, the total area of publicly-owned freshwater lakes  is
58,818 hectares (IEPA 1975).

    Illinois lacks pristine lakes such as those found in northern Minnesota
and Wisconsin.  Illinois lakes, however, exhibit a range of morphologic,
water quality and usability characteristics.  Table 1 lists brief comments
regarding lake types in Illinois.

Lake Succession

    Lakes, although giving the impression of permanence when measured on  the
scale of the human lifespan, are transitory features of the earth's surface.
Most lakes, regardless of their origin, pass through the process  of
ecological succession that ultimately results in a terrestrial  environment.
The ephemeral nature of natural lakes is a consequence of two fundamental
processes — the downcutting of the outlet and, more importantly, the
deposition of allochthonous and autochthonous materials in  the basin.  While
downcutting of the outlet is of little consequence to Illinois artificial
lakes and reservoirs, loss of depth and capacity occurs because of sediments
delivered by streams and from bank erosion.

    Many lakes (presumably) commence the successional  process as  bodies
possessing relatively low concentrations of nutrients and,  generally, low
levels of productivity.  Edmondson (1974) suggested that the idea that all
lakes are born oligotrophic and gradually become eutrophic  as they age is an
old misconception.  The importation and deposition of materials (e.g.,
sediment) from the shoreline and the surrounding watershed  gradually
decreases the lake depth.  The addition of allochthonous materials normally
enriches the water and thereby stimulates the production of autochthonous
organic materials.  Autochthonous materials increase the sedimentation rate
and accelerate succession.  Marked floral and faunal  changes occur.   Algal
blooms become more common along with submergent and,  eventually,  emergent
aquatic macrophytes.  Desirable game fish may be replaced by less desirable
species, the so-called rough fish.  A lake eventually becomes a marsh or
swamp that, in turn, terminates as dry land.

    Lindeman (1942)  stressed the productivity aspects in relation to  lake
succession.  Figure 6 represents the probable successional  productivity
relationships for a hypothetical  hydrosere developing from  a moderately deep
lake located in a fertile humid continental region.  Productivity is
initially low, a consequence of low nutrient levels,  but increases rapidly  as
nutrients become more available.   The length of time required for completion
of the successional  process is a function of several  factors including lake
basin morphology, climate, and the rate of influx and nutrient value  of
allochthonous materials.   It is readily apparent that allochthonous nutrients
can drastically increase lake productivity and thereby shorten the lifespan
of a lake.
                                     18

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                           TABLE 1.  DESCRIPTION OF LAKE TYPES IN ILLINOIS
Parameter
                                               Natural  Lakes
Glacial
            Backwater
                   Normal
                 Flowage
Location      Limited to northeastern
              Illinois including Cook,
              Lake, and McHenry Counties.

Physical/     Small (most are less than
 morpholog-   80 ha).  Long retention
 ical char-   time.  Location of maxi-
 acteristic   mum depth is highly
              variable.  Shoreline tends
              to be regular while the
              basin is cone shaped.
              Very long life expectancy,
              a consequence of low
              nutrient levels and the
              inorganic nature of lake
              bottom.

Water         Start out oligotrophic
 quality      (low nutrient levels) and
              eventually become eutro-
              phic (nutrient rich).
              Impacted by culturally
              induced eutrophication.
           Northeastern II1inoi s,
           particularly the Fox-
           Chain of Lakes.

           Varying in surface
           area from about  40 ha
           to several thousand
           ha.  Very short
           retention time with
           large flow through.
           See normal  glacial
           lakes (except that
           water quality is
           significantly affected
           by sediment-related
           turbidity).
Along major streams including
the  Illinois, Mississippi,
and  Ohio  Rivers.

Wide range of sizes.  Typically
(very shallow with  a flat
'bottom profile and short
retention time.
Water quality is a reflection
of river water quality.  High
sediment-related turbidity,
generated by rough fish, wind
action, and runoff, is a major
limiting factor.  Generally high
in nutrients with large amounts of
sediment deposited when the river
floods.
                                                                                             (continued)

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                                               TABLE 1.  (continued)
      Parameter
                                                    Natural Lakes
                                Glacial
           Backwater
                         Normal
                                                 FTowage
PO
o
Water         Exhibit classical  symptoms
 quality      associated with eutrophica-
              tion (e.g., algal  blooms,
              aquatic macrophytes,  deple-
              tion of dissolved  oxygen).
              Water transparency varies.
              Lakes tend to have a
              homogeneous water  quality.
              Alkalinity, hardness, and
              conductivity are generally
              high.  Ground water con-
              tributes to recharge.

Watershed/    Watersheds tend to be
 shoreline    small, with the drainage
 uses         area/lake capacity ratio
              also being small.   Water-
              shed is generally  urban
              or suburban.  Typically,
              having much development
              around the lakeshore.

Lake usage    Very heavy recreational
              use, primarily boating,
              fishing, and swimming.
                                                 Very large watersheds,
                                                 with drainage area/
                                                 lake capacity ratios
                                                 also extremely large.
                                                 Otherwise, they are
                                                 similar to normal
                                                 glacial lakes.
                                                 (See normal glacial)
Very large watershed.  Usually
having little shoreline
development.
Used primarily for flood pro-
tection, hunting, and fishing.
Waterfowl  habitat.
                                                                                                  (continued)

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                                          TABLE 1.  (continued)
Parameter
                                               Natural  Lakes
                                Glacial
                                                                 Backwater
                   Normal
                                   Flowage
Comments
                                                      Very difficult to manage  and
                                                      limit pollution inputs  because
                                                      of the riverine influence.
Parameter
                            Artificial
                      Reservoirs
                                                     Impoundments
                  North
                        Central
                          South
                               Other
                      (Borrow Pits, Strip Mines,
                      and Quarries)	
Location
Physical/
 morpholog-
 ical  char-
 acteristics
Varying in surface
area but with
moderate to long
retention.  Max-
imum depth at the
dam.  Irregular
shoreline.
Varying in surface
area from very
small to more than
4,000 ha.  Short
retention time
with maximum depth
at the dam.  The
lakebed is rich
agricultural
soil , high in
nutrients and or-
ganic materials.
The shoreline is
irregular.
Surficial recharge.
Varying in surface
area with short to
long retention time.
Maximum depth at
the dam.  Very
irregular shoreline.
Lakebed consists
primarily of claypan
soils that are
lower in nutrients
and organic content
than the central
reservoirs.
Surficial  recharge.
Borrow pits are con-
centrated in or near
urban centers and along
highways.  Generally, have
long retention periods and
are regulated by ground
water level.
                                                                                             (continued)

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                                             Table 1.  (continued)
     Parameter
                           Artificial Impoundments
                     Reservoirs              	
                       North
                       Central
                           South
                               Other
                      (Borrow Pits, Strip Mines,
                      and Quarries)	
     Water quality
High alkalinity,
conductivity,
and hardness.
ro
     Watershed/
      shoreline
      uses
Medium to high
alkalinity, con-
uctivity, and
hardness.  Gen-
erally eutrophic
from the day res-
ervoir started to
fill.  Extremely
high nitrogen and
phosphorus levels.
Turbidity and
siltation are major
problems.  May be
light limited and,
therefore, do not
exhibit some of
the secondary
effects associated
with classical
eutrophication.

Watersheds vary
in size.  Drain-
age area/lake
capacity ratios
vary.  Watershed
is primarily in
row crops.  Non-
point pollution
is a major prob-
lem.  Some urban
Low alkalinity, con-
ductivity, and hard-
ness.  Generally
clearer than
central Illinois
impoundments
except when there
is heavy runoff.
Some have algae and
macrophyte problems.
Clear unless there is
heavy runoff.  Wide
range in water quality.
                                        Watersheds vary in
                                        size but are gen-
                                        erally smaller than
                                        those of central
                                        Illinois.   Watersheds
                                        are primarily forest-
                                        ed or not  under as
                                        intensive  row crop
                                        cultivation as those
                                        of central Illinois.
                       Generally fed by
                       ground water.
                                                                                                  (continued)

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                                              Table 1.   (continued)
     Parameter
                           Artificial  Impoundments
                     Reservoirs
                       North
                       Central
                          South
                              Other
                     (Borrow Pits, Strip Mines,
                     and Quarries)	
     Watershed/
      shoreline
     Lake usage
PO
CO
Recreation is the
primary use.   A
few serve as
public water
suppl ies.
influence.  There
may be a moderate
degree of develop-
ment around the
shorel ine

Many serve as
public water
supplies.  Rec-
reational usage
is primarily
fishing and
boating.
Little urban in-
fluence except in
some cases where
developed along the
shorel ine.

Many serve as
public water sup-
plies.  Recreational
usage includes swim-
ming, fishing, and
boating.

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                        EUTROPHY
ro
O

Q
O
CC
Q.
                                                                              CLIMAX
                                                                              VEGETATION
                                                                   BOG FOREST
         OLIGOTROPHY
                                                            MAT
                                              SENESCENCE
                                              TIME
         Figure  6.  Hypothetical  productivity growth-curve of a  hydrosere (adapted from  Lindeman 1942).
                   Lindeman  describes  the curve as representing a hydrosere "developing  from a
                   moderately deep lake in a fertile cold temperate climatic condition."   It must be
                   kept in mind  that  this is a generalized curve and that not all lakes will follow
                   it in total.   For  example, lakes that are light limited because of suspended
                   inorganic materials  may never experience the initial dramatic increase  in productivity.

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    In Illinois lakes, sedimentation is  considered  to be more significant
than lake production in terms  of  affecting their usable lifespan.  Most
Illinois lakes, whether recently  impounded or old,  have high productivity
potential.

Eutrophication

    The word eutrophication is often used to denote the process whereby a
pristine water body (e.g., lake)  is  transformed  into one characterized by
dense algal  scums, obnoxious odors,  and  thick beds  of aquatic macrophytes.
However, the word has been applied differently,  according to the respective
interests of its users.  Weber (1907)  used the German adjectival form of
eutrophication, "nahrstoffreichere"  (eutrophe),  to  describe the high
concentration of elements requisite  for  initiating  the floral sequence in
German peat bogs (Hutchinson 1973).   The leaching of nutrients from the
developing  bog resulted in a condition of "mittelreiche" (mesotrophe) and
eventually  "nahrstoffearme" (oligotrophe).  Naumann (1919) applied the words
oligotrophic (underfed), mesotrophic,  and eutrophic (well-fed) to describe
the nutrient levels (calcium,  phosphorus, combined  nitrogen) of water
contained in springs, streams, lakes,  and bogs  (Hutchinson 1973).  Naumann
(1931) defined eutrophication  as  the increase of nutritive substances,
especially  phosphorus and nitrogen,  in a lake.   Hasler (1947) broadly
interpreted eutrophication as  the "enrichment of water, be it intentional or
unintentional  ...."  Fruh et al.   (1966) defined the word as the
"... enhancement of nutrients  in  natural water  ...." while Edmondson (1974)
suggested that many limnologists  seem  to use the term to describe "... an
increase in the rate of nutrient  input ...."  Hasler and Ingersoll (1968)
suggested that eutrophication  is  the "... process of enrichment and aging
undergone by bodies of fresh water  ...." Vollenweider (1968) summarized the
eutrophication of waters as meaning  "... their enrichment in nutrients and
the ensuing progressive deterioration of their quality, especially lakes, due
to the luxuriant growth of plants with its repercussions on the overall
metabolism  of the water affected  ...."  A search of the literature on
eutrophication indicates that  the meaning of the term, originally limited to
the concept of changing nutrient  levels, has been gradually expanded to
include the consequences of nutrient enrichment.

    Eutrophication occurs both naturally and as  a result of rrvan1 s activities
(cultural or anthropogenic eutrophication).  Many of man's practices relating
to the disposition of municipal sewage and industrial wastes and to land use
impose relatively large nutrient  loadings on many lakes and rivers.  In many
cases, the  enrichment results  in  algal blooms and other symptoms of
eutrophication.  The consequences of man-induced eutrophication often make
the water body less attractive to potential users.  More importantly, at
least when a long-range viewpoint is adopted, eutrophication accelerates lake
succession and shortens the time  period  before a lake loses its identity.

    A comment regarding eutrophication is in order.  In the popular press and
the mind of the layman, the term  is  equated with a  "bad" or highly
undesirable situation.  Certainly when the enrichment levels reach extremes
and undesirable manifestations occur (e.g., algal blooms, fish kills,
obnoxious odors), the water body  loses much of  its  value as a natural

                                     25

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resource.  However, enrichment of natural waters can result in increased
primary productivity, leading to a larger biomass of consumers.  Eutrophic
water bodies often provide excellent warm-water fisheries.

    The lakes of  Illinois are undergoing eutrophication and the successional
process as previously described.  However, many of the lakes do not exhibit
the secondary effects of eutrophication (e.g., algal blooms) because the
silt-related turbidity of these waters greatly reduces light penetration,
resulting  in  light-limited conditions.  Water quality in Illinois streams and
lakes is appreciably affected by dissolved and suspended matter carried by
runoff  from the land surface.  IEPA (1976) provides an overview of the
situation  in  Illinois; the following paragraph draws heavily from their
reports.

    Agricultural  runoff and  soil erosion are two nonpoint sources that affect
the water  quality of Illinois lakes and streams.  Other major nonpoint
sources (of a more localized nature) that affect water quality include active
and abandoned coal-mining areas, intensive livestock and specialized
agricultural  operations, and storm drainage from urbanized areas and
construction  sites.  Agricultural runoff and runoff from ordinary
precipitation events contain many contaminants (e.g., organic materials that
are oxygen demanding, minerals derived from the soil or applied by man, fecal
coliform bacteria, pesticides, herbicides, fertilizers, and other chemicals)
from ground surface and ground cover that have accumulated through natural
processes  and nonintensive land husbandry.  When rainfall of sufficient
intensity  occurs, soil erosion results.  The severity and frequency of soil
erosion is a  function of many factors including intensity of immediate
rainfall,  prior climatic conditions, soil cover, soil texture, topography,
and antecedent human activities.  The eroded soil contributes both dissolved
and suspended matter to the flowing waters.  The suspended matter may impair
the recreational  use of the body of water as well as such vital biological
functions  as photosynthesis, respiration, reproduction, feeding, and growth.
The suspended materials contributed by agricultural runoff and erosion may
also be deposited in streambeds and lake beds.  The deposited soil  can bury
aquatic life, create an oxygen demand, and release nutrients and chemicals to
the flowing stream or overlying lake water.  The influx of  nutrients to a
lake, assuming they are not deposited on the bottom and overlain by other
materials, tend to make the water body more eutrophic.  The accumulation of
materials  on the  lake or reservoir bottom decreases the water depth and moves
the water  body closer to the time when its identity as a lake or reservoir is
lost.
                                     26

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                                  SECTION 5


                           METHODOLOGICAL OVERVIEW
    Most attempts to classify or ordinate lakes  employ contact-sensing
techniques coupled with the observations of the  field crew to  document the
characteristics of the water bodies.   The major  constraints of most
classification systems are the neccessity for elaborate field  data,
difficulties in obtaining data for all  lakes within a comparable time period
or comparable physical circumstances, and lack of sufficient or appropriate
sample locations to characterize the  entire lake.

    A good historical  data base for most lakes in Illinois is  either not
available or not suited to the development of an overall  lake  classification
system.  Several attempts to characterize these  lakes according to sample
data and field observations have had  limited usefulness since  the data were
not intensively collected within a short time period and  since they relied,
in part, upon subjective observations of field personnel.  It  appears that
satellite-borne sensors such as the multispectral scanner carried by LANDSAT
are capable of collecting data of value for lake classification and
monitoring activities.  The LANDSAT space observatories are attractive
because they provide repetitive coverage, a synoptic view, and a  permanent
record.  The LANDSAT capabilities offer a unique opportunity to obtain a data
base that could group the lakes into  categories  according to their spectral
responses and also provide the opportunity to study relationships between
certain trophic indicators and the spectral data with an eye toward the
development of predictive models.  LANDSAT provides what may be an
economically viable technique for collecting data for the entire  surface area
of each lake within a reasonable time period.  In about 25 seconds the
LANDSAT multispectral  scanner (MSS) collects data in four bands of the
spectrum for an area of the earth covering about 34,225 square kilometers.
In regions of the earth where lakes are very abundant, a typical  LANDSAT
scene may contain several hundred to  more than a thousand inland  water
bodies.  With two satellites in operation and assuming cloud-free conditions,
repetitive coverage is provided on a  9-day basis.  Clearly, the satellite
offers certain advantages over conventional contact-sensing techniques.
Before discussing in more detail the  characteristics, capabilities, and
limitations of LANDSAT in the area of lake classification, it  is  necessary
that we examine the optical properties of water.
                                     27

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OPTICAL PROPERTIES OF PURE WATER AND NATURAL WATERS

    It is readily apparent, even to the casual observer, particularly if he
or she is looking downward from an aircraft, that lakes differ in color and
brightness.  Many investigations have been undertaken to develop an
understanding of the processes that result in the observed phenomena.
Although a detailed description of the interaction between electromagnetic
energy and the  components of the hydrosphere and atmosphere is outside the
scope of this report, a brief discussion is essential to gain some
understanding of the principles that both permit and yet constrain the use of
remote-sensing  techniques in lake classificatory work.

    The  interaction between electromagnetic energy and chemically pure water
has been studied by numerous investigators (e.g., Ewan 1894, Sawyer 1931,
Collins  1925, James and Birge 1938, Hulburt 1945, Raman 1922, Dawson and
Hulburt  1937).  The transmission of electromagnetic energy through a material
medium  is  always accompanied by the loss of some radiant energy by
absorption.  Some of the energy is transformed into other forms (e.g.,
chemical)  or to some longer wavelength of radiation (e.g., thermal infrared)
 (James  and Birge 1938).  Pure water is very transparent to violet, blue, and
green  light.  In the infrared region, the extinction coefficient is high with
a complementary low degree of transmission (Table 2).  The absorption
spectral characteristics of pure water can be modified greatly through the
 addition of  dissolved and particulate materials.

     The absorption spectra of natural waters (e.g., lake and ocean) have been
 studied in detail by Jerlov (1968), Duntley (1963), Atkins and Poole (1952),
 Birge  and  Juday (1929, 1930, 1931, 1932), and Juday and Birge (1933), to
mention a  few.  Hutchinson (1957) has summarized the more important attempts
to elucidate the interactions of light with natural waters, particularly with
 regard  to  lakes.

     An  electromagnetic wave impinging on the surface of a lake decomposes
into two waves, one of which is refracted and proceeds into the aquatic
medium  and the  other of which is reflected back to the atmosphere (Jerlov
1968).  The  wave entering the water is refracted as it passes through the
air-water  interface according to Snell's Law, which may be expressed as

                              n = sin(i)/sin(r)

where

     (i)  =  angle of incidence

     (r)  =  angle of refraction

      n  =   refractive index, which for water is approximately 1.33.

    Most of  the electromagnetic energy entering a lake is attenuated through
the process  of  absorption.  Although only a small percentage (less than 3
percent) (Davis 1941) of the incident energy is backscattered from the lake
water volume, this light (volume reflectance) is the focus of interest in the

                                     28

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       TABLE 2.  OPTICAL PROPERTIES OF PURE WATER (ROOM TEMPERATURE)1
Wavelength
(nanometers)
820 (near infrared)
800
780
760
740
720
700
680 (red)
660
640
620 (orange)
600
580 (yellow)
560
540
520 (green)
500
480
460 (blue)
440
420
400 (violet)
380 (ultraviolet)
Extinction
Coefficient
2.42
2.24
2.31
2.45
2.16
1.04
0.598
0.455
0.370
0.310
0.273
0.210
0.078
0.040
0.030
0.016
0.0075
0.0050
0.0054
0.0078
0.0088
0.0134
0.0255
Percentile
Absorption
91.1
89.4
90.1
91.4
88.5
64.5
45.0
36.6
31.0
26.6
23.5
19.0
7.0
3.9
3.0
1.6
0.77
0.52
0.52
0.70
0.92
1.63
2.10
Refractive
Index



1.329




1.331



1.333




1.338



1.343


*Adapted from Hutchinson (1957)


remote-sensing aspect of water quality investigations.  Its spectral
characteristics have been shaped by the materials found in the lake's waters
(dissolved and suspended materials, plankton, aquatic macrophytes, and air
bubbles).

    The attenuation of electromagnetic radiation in lake waters is a
consequence of the relatively unselective effect of suspended particulate
materials and the highly selective effect of dissolved coloring matter,
usually of organic origin, on the electromagnetic spectrum.  The dissolved
matter absorbs strongly in the violet and blue wavelengths, moderately in the
middle wavelengths (e.g., green), and only weakly at longer wavelengths
(Hutchinson 1957).  When the dissolved materials are present in small
quantities, the water will be most transmissive in the green wavelengths.
Lake waters with large amounts of dissolved substances are more transmissive
in the orange and red wavelengths than in the shorter wavelengths.  However,
the transmission of red and orange light is still greater in pure water than


                                     29

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in water containing participate or dissolved materials.  As water
transparency diminishes, the detectable electromagnetic energy will be of
progressively longer wavelength at increasingly shallower depths (Hutchinson
1957).

    The color of a lake is the color of the electromagnetic energy back-
scattered from the lake body and reflected from the lake surface to the
sensor.  Lake color need not be, and is usually not, the same as the color of
the lake's  water.  Lake color ranges from the blue of pure water through
greenish blue, bluish green, pure green, yellowish green, greenish yellow,
yellow, yellow brown, and clear brown (Hutchinson 1957).  Welch (1952)
defines water color as "... those hues which are inherent within the water
itself, resulting from colloidal substances or substances in solution" (i.e.,
true  color).  Lakes that are blue in color lack appreciable quantities of
humic materials and colored materials in suspension (e.g., phytoplankton).
The bluer the lake color, the smaller the amount of free-floating organisms
contained in the water (Ruttner 1963).  Waters with a high plankton content
 possess a characteristic yellow-green to yellow color.  The characteristic
color may not be apparent because of masking by other materials (e.g.,
suspended sediments).  Ruttner (1963) suggested that:

          "A lake with very transparent and dark blue, blue-green
         or green water is always oligotrophic.  On the other
         hand, eutrophic lakes always have a relatively low
         transparency and are yellow-green to yellow-brown in
         color; but the determination of these optical properties
         alone will not establish the productivity type, for the
         turbidity can be of inorganic origin, and the color can
         come from humic substances."

    Seston  color (color that is attributable to the reflection spectra of
suspensoids of microscopic or submicroscopic size) is often observed in
highly productive lakes.  Lakes containing large quantities of suspended
inorganic matter (e.g., silt) may acquire a characteristic seston color, but
in most cases the color is related to large concentrations of phytoplanktonic
organisms (Hutchinson 1957).

    Scherz  et al. (1969) have investigated the total reflectance (surface
reflectance plus volume reflectance) curves of pure water and natural waters
under laboratory conditions using a spectrophotometer.  They reported that
the addition of dissolved oxygen, nitrogen gases, and salts (e.g., NaCl,
Na2$04, Na3P04*H20) had no apparent effect on the reflection curve
However, water from lakes in the Madison, Wisconsin, area had reflectance
curves that differed both from the distilled water curve and from each other.
They  attribute these differences to the presence of different algal
organisms,  since filtration of the lake waters produced similar reflectance
curves for  all lakes even though the curves differed from those of pure water
(Figure 7).

    The color of natural waters is the end result of optical processes that
are both numerous and complex.  It is relatively easy to detect differences


                                     30

-------
            10
        o
        LJ
        _J
        u.
        Ill
        or    I
        uj  0.4
        o
        o:
           0.0
               	FILTERED

                   UNFILTERED
             200     400      600      800    1,000    1,200

                      WAVELENGTH    (NANOMETERS)
        u.
        UJ
        a:
            10
        f:   4
        o
        UI
       U
       O
       a:
       ui
       a.
          0.4
          0.0
                — UNFILTEREO
  LAKE

KE60NSA
                 \

             200     400      600     800    1,000    1,200

                     WAVELENGTH    (NANOMETERS)
Figure 7.  Reflection  characteristics  of filtered and  unfiltered water
          samples from two Wisconsin  lakes in the area of Madison
          (adapted from Scherz et al. 1969).
                                31

-------
in color within a lake and also among a population of lakes.  It is, however,
more difficult to attach physical, chemical, or biological significance to
the color,  particularly when quantitative estimates are desired.  The
difficulty  is compounded in waters having more than one class of particulates
present, which is normally the case  in natural water (McCluney 1976), and by
seasonal differences  in color within a lake.  The degree of success in
sensing and interpreting the significance of color is partially a function of
the sensor  type employed for the collection of spectral data.

LANDSAT MULTISPECTRAL SCANNER

Scanner Characteristics

    The LANDSAT MSS  is a line-scanning radiometer that collects data by
creating  images of the earth's surface in four spectral bands:  Green (GRN)
500 to 600  nanometers (nm); Red  (RED) 600 to 700 nm; near infrared-one (IR1)
700 to 800  nm; near  infrared-two (IR2) 800 to 1,100 nm.

    The MSS scans crosstrack swaths  185 km in width, simultaneously imaging
 six  scan  lines for each of the four  bands (Figure 8).  The resultant analogue
 signals  are sampled,  digitized, arranged into a serial digit data stream, and
transmitted to ground stations either in real time or by delayed
transmission.  LANDSAT data enter the public domain through the U.S.
 Geological  Survey's  EROS (Earth Resources Observation System) Data Center
 near Sioux  Falls, South Dakota.  The data are available in the form of
 photographic products (e.g., black-and-white prints) and computer-compatible
 tapes (CCT's).  The  CCT's contain the data in digital form.

     The MSS, as found on LANDSAT-1,  -2, and -3, is a low resolution device,
 both  spatially and spectrally speaking.  Three of the bands (GRN, RED, and
 IR1)  are  100 nm in width while the IR2 band covers 300 nm. Figure 9
 illustrates a generalized spectral reflectance curve for a single picture
element  (the MSS spatial resolution  unit, also called a pixel) of a
hypothetical lake.   The width of the MSS bands disallows the recording of the
fine  details in the  curve.  The MSS output more closely resembles Figure 10.
Responses are given  as values for the various wavelengths bands (e.g., 500 to
600 nm, GRN) instead of specific values for the entire spectral range.  This
procedure crudely defines an entire  range of wavelength responses as four
single readings.

    The nominal MSS  pixel measures 57 by 79 meters, and covers an area of
0.3933 hectares (ha). Through the use of resampling techniques it is
possible to adjust the pixel size (e.g., an 80-meter by 80-meter pixel
corresponding to 0.64 ha was employed in this study). It must be kept in mind
that  the MSS gathers  energy over the area of its nominal pixel.  Many
measurements made using contact techniques are of the point type, a direct
contrast to those acquired by the LANDSAT MSS.  It is commonly recognized
that  some LANDSAT MSS pixels contain a mixture of water and land features.
This  normally occurs  along the water-land interface or in situations where
the water body.is much smaller than the pixel or, conversely, where an island
is much smaller than  the pixel.  The pixel size also tends to give small
water  bodies or those with very irregular shorelines a "blocky  appearance.


                                     32

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   SCANNER
                         •OPTICS
     6 DETECTORS
     PER BAND:
     24 TOTAL
           SCAN MIRROR
           (OSCILLATES
           NOMINALLY
           ± 2.89°)
 NOTE: ACTIVE SCAN IS
       WEST TO EAST
FIELD OF VIEW
= 11.56 DEGREES
                              ACTIVE
                          "''   SCAN
         NORTH

WEST       EAST
                        PATH OF
                        SPACECRAFT
                             TRAVEL
     6 LINES/SCAN/BAND
Figure 8.   Schematic diagram of the LANDSAT-1 MSS scanning arrangement
          (adapted from the Data Users Handbook (NASA 1972)).
                             33

-------
                    GRN

                  500    600    700   800   900   1000   1100
                              Wavelength (nm)
Figure 9.  Generalized spectral reflectance  curve for a single  picture
           element  (pixel) of a hypothetical  lake.
                  V)
                  V)
                  u»
                      GRN   RED    IR1
IR2
                                     I
                   500    600    700   800   900   1000  1100

                               Wavelength (nm)
Figure 10.  Generalized  output of the  LANDSAT MSS in response to the
             spectral distribution illustrated in Figure 9.
                                   34

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A visual examination of imagery generated from the LANDSAT MSS  will  usually
detect a pattern of stripes running nearly orthogonal  to the satellite's
path.  This is a consequence of an imbalance among the MSS's 24 detectors.
The problem is particularly noticeable when working in the digital  domain
(i.e., with the CCT's).

    It should be kept in mind that, although the LANDSAT MSS was designed
with the earth's resources in mind, it was not developed specifically  for
water.  Most of the incident solar energy entering a water body is  attenuated
through absorption.  The volume reflectance of a water body is  generally less
than three percent of the incident light.  Thus, the energy reaching the MSS
from water bodies is relatively small  in magnitude compared to  that received
from land features.  While it is possible to increase the MSS's gain in the
GRN and RED bands, this is not normally done.

Peripheral Effects

    The character of the electromagnetic energy impinging on the remote
sensor, the LANDSAT-1 MSS in this case, has been shaped through interactions
with numerous environmental phenomena (Figure 11).  Some of the interactions
are highly desirable because they mold the character of the light,  which may
then be interpreted in terms of some parameter of interest (e.g., Secchi
depth).  Other interactions of light energy with the environment (e.g.,
atmospheric scatter) may be detrimental to a particular study.   What may be a
vitally important interaction in one study may be devastating in another.

    The earth's atmosphere has a pronounced effect on the solar spectrum and
on lake water color as sensed from aircraft and satellite altitudes.
Atmospheric conditions (e.g., degree of cloudiness; presence of fog, smoke,
and dust; amount of water vapor) affect the degree of insolation attenuation.
Weather conditions strongly affect the distribution of energy between
sunlight and skylight (Piech and Walker 1971), contributing a degree of
uncertainty in water quality assessment through remotely sensed color
measurements.  Hulstrom (1973) has pointed out the adverse impact that cloud
bright spots can have on remote-sensing techniques that utilize reflected
energy.

    The degree of scattering and absorption imposed on the return signal  from
water bodies is related to atmospheric transmittance and can result in
changes in lake color when sensed at aircraft-high flight and satellite
altitudes.  The attenuated return signal is also contaminated by
electromagnetic radiation from the air column (path radiance).   Rogers and
Peacock (1973) have reported that solar and atmospheric parameters  have a
serious adverse impact on the radiometric fidelity of LANDSAT-1 data.   Path
radiance was found to account for 50 percent or more of the signal  received
by the MSS when viewing water and some land masses.  The magnitude  of  the
adverse atmospheric effects can be reduced, though not completely eliminated,
by using imagery or digital data collected on clear, cloudless  days.  This is
the approach used in this investigation.

    The LANDSAT-1 spacecraft passes over the same point on the  earth at
essentially the same local time every 18 days.  However, even though the  time

                                     35

-------
                                                                                            Sun
01
                            LANDS AT
                                                      Skylight
                              LJULT
                                                      i
                                                   Backscatter
                                             Volume
                                           Reflectance
                                                                  Surface
                                                                  Effects  Bottom
                                                                         Effects
                                                                          L
 Cloud
Shadow

          Figure 11.  Some components  and  interactions of light  with  a  hypothetical lake and  the  atmosphere,

-------
of flyover will  remain essentially the same throughout the year,  solar-
elevation angle  changes cause variations in the lighting conditions  under
which the MSS data are obtained.  The changes are primarily the result of  the
north or south seasonal motion of the sun (NASA 1972).  Changes in  solar-
elevation angle  produce changes in the average scene irradiance as  seen  by
the sensor from  space.  The change in irradiance is influenced both  by the
change in the intrinsic reflectance of the ground scene and by the  change  in
atmospheric backscatter (path radiance).  The actual effect of a changing
solar-elevation  angle on a given scene is very dependent on the scene itself
(NASA 1972).  For example, the intrinsic reflectance of sand is significantly
more sensitive to a changing solar-elevation angle than are most types of
vegetation (NASA 1972).  The effects of a changing solar-elevation  angle are
of particular importance when comparing scenes taken under significantly
different angles.  The use of color ratios in lieu of raw data values may  be
of value in reducing the magnitude of the solar angle-induced effects by
normalizing the  brightness components.  The approach is given some
consideration in this study.

    A portion of the radiation impinging on the lake surface will be
reflected.  The  percentage of surface-reflected energy is a strong  function
of the angle of incidence.  The light reflected from the water-atmosphere
interface is composed of diffuse light from the sky (skylight) and  specularly
reflected sunlight.  Specular reflection areas contained in a scene are  of
little value in  most water studies, the possible exception being the
determination of surface roughness.  The specularly reflected radiation
exceeds, by several orders of magnitude, the reflected energy emanating  from
beneath the water surface (Curran 1972).  Surface-reflected skylight,
containing no water-quality color information, can comprise from 10 percent
of the return signal on a clear day to 50 percent on a cloudy day (Piech and
Walker 1971).  The surface-reflected skylight not only increases the apparent
reflectance from the water body (volume reflectance) but also affects the
shape of the reflectance curve.  Surface roughness is known to have an effect
on the percentages of  light reflected and refracted at the interface (Jerlov
1968).  However, the effect of surface roughness is negligible in estimating
total radiation entering a water body when the solar-elevation angle is
greater than 15 degrees (Hutchinson 1957).

    The lake bottom characteristics (color and composition) will also affect
the intensity and the  spectrum of the volume reflectance in settings where
water transparency permits the reflection of a significant amount of
radiation from the bottom materials.  In studies involving the estimation of
water depth or the mapping of bottom features, it is essential that the  lake
bottom be "seen" directly or  indirectly by the sensor.  Bottom effects are
capitalized upon and  put to a beneficial use.  However, in this
investigation, bottom  effects are considered to be an undesirable peripheral
effect.  A sensor with the capabilities of the LANDSAT MSS is not able to
"see" much deeper into a  lake than the Secchi depth.  The Secchi transparency
of Illinois lakes is,  in most cases, relatively small (e.g., less than one
meter) when cqmpared  to the mean depth  of each lake.  The assumption is  made,
as a first approximation, that the bottom effect is relatively insignificant
when considering each  of  the  selected lakes as an entity.
                                      37

-------
     It is evident that many factors influence the intensity and spectral
 characteristics of the electromagnetic radiation that is collected by the
 sensor.   Absolute quantification of remotely sensed phenomena requires that
 all  of the adverse effects be accounted for in the return signal.   Failure to
 account for all of the variation introduced by the detrimental  effects might
 be criticized as being simplistic or naive.  However, given the present
 "state of the art" along with manpower, time, and monetary constraints, and
 the ex post facto nature of the project, a complete accounting  is  not
 possible.

 SATELLITE SENSING OF ILLINOIS LAKES

     A visual examination of LANDSAT MSS imagery indicates that  gray-tone
 differences can be detected in the study population of Illinois lakes.
 Figures 12 through 15 represent, respectively, the IR2,  IR1,  RED,  and GRN
 gray-tone images of LANDSAT scene 1448-16023.   The IR2 image  (Figure  12)
 clearly demonstrates a great contrast between water bodies and  terrestrial
 features.  Water is an excellent absorber of radiation wavelengths  comprising
 the IR2 band, so water bodies appear black.  Figure 13,  the scene's IR1
 counterpart, exhibits a similar contrast between water and land.   A careful
 examination of the water bodies suggests surface or near-surface phenomena  in
 some lakes.  Gray-tone differences both within specific  water bodies  and
 among members of the lake population are most pronounced in the RED image
 (Figure 14).  In this band, lakes with extremely turbid  water often meld  with
 the terrain features, a consequence of similar gray-tone values.   A vivid
 example is presented in Boland (1976).   Though less obvious to  the  eye,
 gray-tone differences are also noted among  water bodies  in the  GRN-band image
 (Figure 15).

     When viewing LANDSAT scenes such as  the black-and-white standard
 photographs produced by the EROS Data Center,  it should  be kept in  mind that
 no special  effort has been made to enhance  water bodies  and related
 phenomena.   Indeed, a loss of spectral  information  occurs  when  the  MSS
 digital  data are transformed into photographic  products.   Specifically, the
 products have a relatively small  density range  compared  to the  sensitivity
 range  of the MSS.  This results in a scale  compression when the MSS data  are
 transformed into a film image on an electron beam recorder.   In addition, the
 range  of energy returns from water bodies is  small  and concentrated at  the
 lower  end of the MSS intensity scale.   Scale compression coupled with the
 small  range of digital  number (DN)  values adds to the difficulty of
 determining trophic state index and indicator  values through visual and
 densitometric evaluation  of "standard"  EROS black-and-white photographs.

    As can  be seen  from Figures 12,  13,  14, and  15, it is  possible  to detect
 spectral  differences  for  Illinois  lakes  using LANDSAT imagery coupled with
 photointerpretive techniques.   The  real  problem  is one of  relating  the
 spectral  variations to  chemical, biological, and  physical  phenomena
 measurable through contact-sensing techniques or acquired through
 ground-level  observation.

    As indicated  earlier, the  quantity and  spectral composition of  radiation
directed upward across the water-atmosphere interface is,  in part,  a function

                                     38

-------
Figure 12.
IR2 image of LANDSAT scene 1448-16023  (October 14, 1973).  The
IR2 band is excellent for separating water bodies from land.
                                    39

-------
Figure 13.   IR1  image  of LANDSAT scene 1448-16023 (October 14,  1973).  The
            band is excellent for discriminating water from terrain.
            Surface or near-surface phenomena are evident  in  some of the
            water bodies.
                                   40

-------
Figure 14.   RED  image of LANDSAT scene 1448-16023 (October 14, 1973).
            Variations in water body gray tones  suggest differences in
            water qua! ity.


-------

Figure 15.   6RN image of LANDSAT scene 1448-16023 (October 14,  1973).
            While  lacking the contrast of the RED, IR1,  and IR2 images
            of the scene, gray scale differences are still  evident  among
            the water bodies.  Compare with Figures 12,  13, and 14.
                                42

-------
of the dissolved  substances  and  particulate materials in the water.   While
water itself  is capable  of scattering and absorbing light,  the major  portion
of the scattering is  caused  by materials in the water.   Scattering as a
result of dissolved color is highly selective,  while suspended solids tend to
affect volume reflectance in a rather nonselective fashion.  It then  follows
that increases in suspended  particulate materials in lake water will  tend to
increase the  reflectance in  the  LANDSAJ bands.

    It should be  noted that  some natural waters will, at least for a  portion
of the spectrum,  exhibit a lower volume reflectance than pure water.   Humic
waters have this  characteristic  as demonstrated by Rogers (1977)  and  shown in
Figure 16.  Humic or  "brown  water" lakes are relatively common in the
northern portions of  Minnesota,  Wisconsin, and  Michigan. They are much  less
common in Illinois, and  none of  the lakes included in this  project are of the
humic type.

    Rogers (1977)  and Scherz et  al. (1975) have demonstrated a simple and
practical  technique to determine the spectral  signatures of lakes.  The  term
"satellite residual fingerprint" is used to identify the isolated spectral
signature.  Their approach is as follows.

    If a very deep, clear lake is found in a LANDSAT scene, and assuming that
bottom signals are not present or at least are  insignificant, it follows that
the electromagnetic signal received from the lake by the MSS is attributable
to lake surface signals, plus a  very small amount of backscatter from the
water molecules,  and  atmospheric effects.  If another lake  containing
dissolved and or  suspended solids that interact with light  is present in the
scene, then subtracting  the  spectral band values for the clear lake from the
corresponding band values of the second lake will result in a residual
spectral curve that is related to the impurities present.  Computation of the
difference for one or several MSS bands can result in the aforementioned
satellite residual fingerprint.   A graphic example of the technique is seen
in Figure 17. The upper portion of the figure  illustrates  the raw spectral
curves (i.e., spectral signatures) for three Wisconsin  water bodies:  Yellow
Lake (algal-laden), Moose Lake (humic), and Grindstone  Lake (clear).   The
lower set of  curves (i.e., satellite residual  fingerprints) were obtained by
subtracting the clear lake MSS DN value for each band from  its counterpart in
each of the other lakes.

    Though lacking the elegance  often associated with attempts to remove
atmospheric effects through  mathematical modeling, the satellite residual
fingerprint technique has much appeal.  It is,  however, dependent on  the
presence of deep, clear  lakes.  With the exception of Lake  Michigan,  Illinois
lacks such lakes.

    Piech and Walker  (1971)  have demonstrated a method  called the scene  color
standard (SCS) technique* for the removal of peripheral effects in water
quality surveys.   The technique  is attractive because no ground truth is
required for  removing the peripheral effects.   The SCS approach employs  a
  Patent pending.

                                     43

-------
  1.5
  1.0
O
i
i
3
 s
  -0.5"
  -1.0
             -— Algal- Ladened Water
                                — Clear or Distilled Water
           A—Humic Water
                      -Range of LANDS AT MSS Bands-
                                              IR2
CRN I RED I  IR1 I
                                                                 1
    400     500    600    700     80O    900
                         Wavelength (nm)
                                   1000
                                                                 1100
Figure 16.  Characteristic "fingerprints" of clear or distilled water, humic
           water, and algal-laden water.  The ordinate  is scaled in
           percentage of laboratory difference (D^ = (pvi - Pv])/Ppi
           where D»i and P..I  are the volume reflectances for the wat
                                            er
   where Pvi an  pvi
   in question and distilled water, respectively, and ppi_ is the
   "fingerprint" obtained  under laboratory conditions (adapted from
   Rogers (1977).
                           44

-------
O)
    40
     30-
B-
M,
Q    10
z
Q  ior
Q>
O
2
  (0 -10 •
  c
  0)
                   • Yellow Lake (Algal-Laden)
                   A Grindstone Lake (Clear)
                   • Moose Lake (Humic)

             MSS Residual Signals For Three Types Of Lakes
            <	Spectral Range Of LANDS AT MSS Bands
     400    500    600    700     800    900    1000   1100   1200

                         Wavelength (nm)
  Figure 17.  LANDSAT MSS spectral signatures and residual  curves for three
           types of lakes  (modified from Rogers (1977)).
                             45

-------
combination of known reflectances from natural objects and certain
characteristic shadow areas within the scene.  Unfortunately, shadows of a
size compatible with the  spatial resolution of the LANDSAT MSS are either
lacking in the Illinois scenes or confined to a geographically restricted
area.  In addition, the reflectances of  sunlit natural objects in
juxtaposition with the shadows (in this  case cloud shadows) are not known.
Therefore, the SCS technique cannot be employed to remove the peripheral
effects from  Illinois MSS lake data available for this project.

     It has been well documented that the MSS is incapable of directly
detecting substances such as nutrients (e.g., phosphorus) in water.  This
does not mean, however, that it is impossible to get some estimate of such
substances.   Phosphorus,  for example, is known to be a key element in primary
productivity, stimulating the production of biomass.  Differences in nutrient
levels are often  directly related to the magnitude of the manifestations of
eutrophication  (e.g., turbidity, chlorophyll a^, algal blooms).  Such
phenomena are sensible to the MSS.  Again, it should be kept in mind that the
energy return from natural water bodies  is generally low compared to that
from land features.  Thus, all of the water quality related information is
contained in  a relatively small range of DN levels for each band for the
 Illinois lakes  (Figure 18).  This precludes developing trophic indicator
estimates that have the accuracies and precisions of the contact-sensed data.

     This project  is based on the premise that the volume reflectances of
water bodies  represent distinct characteristics of their optical properties,
which  are then interpretable in terms of parameters considered important in
 assessing the trophic state.  This concept assumes:

     1.   Waters with similar optical properties will yield similar
         spectral  responses.

     2.   Under identical light conditions, the volume reflectance as
        measured  in all LANDSAT bands will generally be lowest for
        clean water lakes.  The inverse  is also assumed.

     3.  Detritus, phytoplankton, suspended solids, and most other natural
         large particulates are Mie scatters and, therefore, scatter
        approximately uniformly over the spectrum sensed by the MSS.
        As the quantity of scattering materials increases, there is a
        relatively uniform increase in the reflectance curve (Piech
        and Walker 1971).  In other words, the reflectance curve
        will become higher and flatter as the water becomes more
        turbid.

     4.  Substances (e.g., phosphorus) that are not sensible to the MSS,
        can be sensed indirectly through their effects on parameters
        that are sensible to the MSS.

     5.  Shifts in dominant-color reflectance from the blue range toward
        the red-brown range reflect increases in lake productivity or are
        associated increases in dissolved color or inorganic turbidity.
                                     46

-------
    60-
Reflectance (DN)
50-
40-
30-
20-
10-
\
GRN
V
\
s.
V*
X
RED
\
\
V,
X
\
IR1
^•^

\
IR2

500 600 700 800 900 1,000 1,100
                    LANDSAT MSS Bands (nm)
Figure la.  Range of MSS data for 145 Illinois lakes.   The data,  averages
           for each lake,  were acquired  October 14,  15, and 16,  1973, and
           adjusted to a common date (October 15) using regression analysis.
                                  47

-------
    It should be recognized that the data used for calibration purposes in
this project were collected with no thought of their being used in a
satellite-related project.  Thus, some highly desirable parameters (e.g.,
total suspended solids, organic particulates, inorganic particulates) were
not measured during the time of satellite flyover.  In some cases the
location of the contact-sensed data stations was less than nominal when
viewed through the "eye" of the satellite.
                                    48

-------
                                 SECTION 6


                                  METHODS
DESIGN OVERVIEW
    LANDSAT MSS data can be used to classify lakes and reservoirs with little
or no a  priori knowledge about the water bodies.  However, past experience
has shown that the full capabilities  inherent  in the LANDSAT MSS can only be
utilized if the MSS. data are used in  conjunction with water quality data
obtained through contact sensing concurrent or nearly concurrent with
satellite flyover.  The inclusion of  contact-sensed data  in the study
provides the opportunity to examine the satellite MSS data for statistical
relationships  (correlations) with specific water quality  parameters.  If
correlations exist, it may then be possible to develop models of practical
value for the  estimation of trophic  indicators and  index  values.

    At this time no generalized model  exists that incorporates LANDSAT MSS
and contact-sensed data for the estimation of  a trophic  indicator or  index
for all  inland water bodies at different times of the year; it is necessary
to develop regression models specific to a date of  LANDSAT coverage.  This is
accomplished by elucidating the relationships  between the MSS data and
specific trophic indicators and indices for a  relatively  small group  of
benchmark lakes. The resulting regression models are then employed to
estimate the magnitudes of  indicators and  indices for other lakes in  the
LANDSAT  scenes.  The need for  some contact-sensed data  requires that  either
field crews be dispatched to sample  a relatively small  number of lakes in the
State, in this case  Illinois,  or that the  requisite data  be drawn from
existing data  banks.   The second option  is attractive for both economic and
logistic reasons and was  selected for this project.

DATA ACQUISITION

    In 1973, the U.S.  Envirormental  Protection Agency's National
Eutrophication Survey  (NES)  sampled  31 Illinois lakes and reservoirs  during
three periods  -- May 7-12,  August 7-10,  and  October 16-19.  Details on the
sampling procedures  and  analytical techniques  are found in  U.S. EPA  (1975).
The data are stored  in the  U.S. EPA's STORET system.

    Over 100 Illinois  lakes were  sampled  by  IEPA during late  spring and
simmer of 1977 (June 15  through August 21).   Lake  selection criteria
(generally adhered to)  included  a minimal  surface  area  of 40  hectares and
public access.  The  water bodies, well dispersed geographically, were sampled
by means of boats.  Each was visited once and generally sampled  at three
sites.  Parameters measured included temperature, dissolved oxygen,  Seccni

                                     49

-------
depth, alkalinity, conductivity, pH, total suspended solids, volatile
suspended solids, total phosphorus, ammonia-nitrogen, and nitrite-nitrate
nitrogen.  Field observations were recorded and phytoplankton were identified
and enumerated.  In addition, a problem assessment was conducted for over 350
Illinois lakes under the Section 208 Water Quality Management Program.
Existing lake data were collected from various sources, and qualitative
evaluations  of lake quality and problems were made by persons familiar with
the lakes.   The details of the 1977 IEPA lake sampling program and the
Section 208  lake problems assessment have been published in a separate report
(IEPA 1978a).

    LANDSAT-1 and  LANDSAT-2 cover more than 95 percent of the State of
 Illinois  in  three  consecutive passes (Figure 19).  A search was initiated
through the  EROS Data  Center to determine the availability of LANDSAT MSS
 scenes for Illinois that were concurrent or nearly concurrent (within a few
days) with the NES sampling dates for the 31 Illinois lakes that were to
 serve as  benchmark lakes from which regression model development would be
 attempted.  Past experience (Boland 1976, Rogers 1977) indicates that lakes
 in the north-central part of the United States are best characterized as to
 trophic status during  the latter part of summer (August to September).  Cloud
 coverage prevented the use of LANDSAT data from the spring and summer NES
 sampling  periods.  For the most part, complete LANDSAT coverage was available
 for Illinois for October 14 to 16, 1973; the NES sampled the lakes from
 October 16 to 19.  Photographic prints and CCT's for 10 LANDSAT scenes were
 ordered through  the EROS Data Center (Table 3).  The IR2 image of each scene
 is displayed as  a  black-and-white print (Figures 20-30).  Each edge of a
 scene represents a distance of 185 km on the earth's surface; a scene
 typically covers 34,200 square km.  The study lakes are identified by serial
 number callouts.   The  names corresponding to the serial numbers are in
 Table 4.

        TABLE 3.  LANDSAT MSS SCENES ORDERED FOR ILLINOIS LAKE STUDY


                Path Number          Date         Scene Number

                   24             10-14-73         1448-16023
                                                   1448-16030*
                                                   1448-16032
                                                   1448-16035

                   25             10-15-73         1449-16082
                                                   1449-16084
                                                   1449-16091*
                                                   1449-16093

                   26              10-16-73         1450-16140
                                                   1450-16142
      *NASA-Goddard did not produce the CCT.


                                      50

-------
      N
Foreward
 Overlap "~\
                                                           LANDSAT
                                                             Coverage
                                                                Of
                                                              Illinois
                                                             October
                                                           14-16, 1973
    Figure 19.  LANDSAT coverage  pattern for the State of Illinois
                with scenes  for October 14-16,  1973.
                                  51

-------
Figure 20.   lR2 image of LANDSAT scene 1448-16023 (October 14,  1973).  The
            massive dark object dominating the scene is the southern end
            of Lake Michigan.  Study lakes and .reservoirs are identified  by
            serial  number call outs.  See Table 4 for their names.
                                    52

-------
Figure 21.   Enlarged portion of LANDSAT IR2 print containing lakes
            and reservoirs found in scene 1448-16023.
                                53

-------
  IU088-30


                         Ha
                                                  -Ticy ; •

                                                '£" •/.^*^W.-.--i'f',% -g(h
                                                                    -
Figure 22.  IR2  image of LANDSAT  scene 1448-16030  (October 14, 1973).
            The  scene's CCT's were  not available from  NASA-Goddard.

-------
                   U888-38I
                                      ness-eel

                U089
 I40CT73 C N38-59/WB88-20 N
          IN838-38
Figure 23.   IR2  image  of LANDSAT  scene  1448-16032  (October 14,  1973)
                                       5E

-------
                                              .;-." *- r-
                                                 -
                                  U689-B8I               W866-
I«OCT73 C N37-3-VHB88-49 N N37-38/U888-42 tBS      SUN EL36 H21«8 I98-B2«-N-1-N-D-IL



   uese-ee
Figure  24.   IR2  image of  LANDSAT scene 1448-16035  (October 14,  1973).

              Several  Illinois lakes are partially or wholly obscured by
              clouds.
                                      56

-------



Figure 25.   IR2 image of LANDSAT scene 1449-16082 (October 15, 1973)




                                  57

-------

                  W089-30I

I50CT73 C N«e-29- !6B&a-7 81
Figure  26.
IR2  image of LANDSAT scene 1449-16084 (October 15, 1973).
The  CCT's for  this scene lacked  the necessary
internal  calibration data.  Most  of the water  bodies were
picked  up because they  appear in  forward or  side overlap
areas  of adjacent scenes; seven  were dropped.
                                     58

-------
I50CT73 C N40-2



    IU090-38
.ABB9-I9 N N08-2B/W089-I I tlSS   7  D SUN EL36 FKI50 ISB-e^Nnj^L^^gS^WS



         14090-001              U089-30I

  ISOCT73 C NSe-B
                      :
                                               9B-6260-N-1-NH3ML NflSf     .-1^9-16091-701

 Figure 27.   IR2 image of LANDSAT scene 1449-16091  (October  15, 1973).
               The scene's CCT's  were  not available from NASA-Goddard.
               Most of  the water  bodies  were  picked up  because they appear
               in forward or side overlap areas  of adjacent  scenes.
                                       59

-------
I50CT73 C N37-32/U096-I7 N N37-ZB-T-BS*



          N037-80I       IU091-B
                                            HZ148 I98-6268-N-I-N-D-IL NRSR ERTS E-l
                                                     r~
                                                                         9-16833-7 81
4-
                                      U096-38I
Figure  28.    IR2  image of LANDSAT scene  1449-16093 (October 15, 1973).


                                           60

-------
160L
                .-
    IU89I-38
                 UB9I-00I

 Figure  29.   IR2  image of LANDSAT scene  1450-16140  (October 16,  1973),
                                      61

-------

Figure 30.  IR2 image of LANDSAT scene 1450-16142 (October 16, 1973).

-------
     TABLE 4.  SERIAL LIST OF ILLINOIS WATER BODIES PROPOSED FOR INCLUSION IN TROPHIC CLASSIFICATION PROJECT
O>
CO

Serial
Number
001
003



003
004
005

006
008
009

010
Oil
012
013

014

015
016
017
018
019
020

Name of STORET
Water Body Number County
Horseshoe
Greenville
New City
(Governor
Bond)
DePue 1752
Spr i ng
Fuller, Taylor,
Bundy
Swan
Spring
Sanganois Con-
servation Area
Me red os i a
Sangchris 1753
Taylorville
Lincoln Trail
State Park
Carlyle 1706

Pa rad i se
Charleston 1708
Wolf
Calumet
Bakers
McGinnis Slough
(Or! and)
Alexander
Bond



Bureau
Bureau
Calhoun

Calhoun
Carroll
Cass, Morgan

Cass, Morgan
Christian
Christian
Clark

Clinton,
Bond, Fayette
Coles
Coles
Cook
Cook
Cook
Cook

Nearby Town
01 ive Branch
Greenville



DePue
Bureau
Graf ton

Grafton
Savanna
Beardstown

Me red os i a
Kincaid
Taylorville
Marshall

Carlyle

Mattoon
Charleston
Chicago
Chicago
Barrington
Or land Park

Latitude
(North)
37-38-32
38-55-45



41-18-38
41-18-05
--

38-57-52
42-03-06
40-06-00

39-53-00
39-38-40
39-31-00
39-20-33

38-43-43

39-25-00
39-27-30
41-40-05
41-41-08
42-08-08
41-38-03

Longitude
(West)
89-21-30
89-33-40



89-19-09
89-21-02
--

90-33-13
90-08-00
90-20-00

90-33-00
89-28-50
89-15-30
87-43-03

89-16-14

88-26-15
88-08-25
87-31-02
87-35-13
88-06-42
87-51-26

Surface Area
(Hectares)
765
314



212
106
61

949
1437
993

685
876
465
59

10522

71
145
170
648
53
127

(Acres)
1890
775



524
262
150

2345
3550
2451

1692
2165
1148
146

26000

176
359
419
1600
130
313

                                                                                                   (continued)

-------
TABLE 4.   (continued)
Serial
Number
021
022
023
024
025
026
027
028
029

030

031

032
033
034
035
036
037
038
039
040
041
042
043
044
Name of
Water Body
Saganashkee
Skokie Lagoons
Tampier
Mat toon
Paris Twin
Sara
Vandal i a City
Moses
Rend

West Frankfort
Old
West Frankfort
New
Old Ben Mine
We-Ma-Tuk
Anderson
Rice
Canton
Murphysboro
Carbondal e
Cedar
Kinkaid
Sam Parr State
Eagle
Fowl er
Gilbert
STORET
Number County
Cook
Cook
Cook
Cumberland
Edgar
Effingham
1764 Fayette
Franklin
1735 Franklin,
Jefferson
Franklin

Franklin

1765 Franklin
1761 Fulton
Fulton
Fulton
Ful ton
Jackson
Jackson
Jackson
Jackson
Jasper
Jersey
Jersey
Jersey
Nearby Town
Willow Springs
Winnetka
Or land Park
Neoga
Paris
Effingham
Vandal ia
Benton
Benton

West Frankfort

West Frankfort

Sesser
Fiatt
Marbletown
Banner
Canton
Murphysboro
Carbondale
Carbondal e
Grimsby
Newton
Graf ton
Graf ton
Graf ton
Latitude
(North)
41-41-28
42-07-13
41-38-53
39-22-00
39-38-27
39-07-50
39-00-35
38-01-13
38-02-35

37-53-37

37-54-18

38-06-15
40-31-56
40-12-00
40-27-30
40-43-53
37-46-52
37-41-49
37-39-52
37-47-47
29-01-10
38-59-45
39-01-50
38-57-30
Longitude
(West)
87-53-04
87-46-42
87-54-22
88-27.-50
87-41-30
88-37-45
89-07-15
88-52-00
88-57-05

88-48-44

88-47-56

89-00-45
90-10-14
90-11-25
89-56-55
89-58-25
89-23-02
89-13-61
89-16-58
89-25-53
88-07-15
90-33-40
90-34-10
90-31-00
Surface
(Hectares)
132
76
66
310
89
237
267
69
7650

59

87

43
60
552
560
101
58
55
728
1113
73
40+
94
122
Area
(Acres)
325
190
163
765
220
586
660
170
18900

146

214

106
149
1364
1383
250
144
136
1800
2750
180
100+
231
300
                                                    (continued)

-------
                                               TABLE  4.  (continued)
en

Serial
Number
045

049
050
051
052
053
054

055
056
057
058
059
060
061
062
063
064
065

066
067
068
069
070
071
072

Name of
Water Body
Flat, Brushy,
Deep, Long
Dutchman
Storey
Holiday
Long
East Loon
SI oc urn

Cedar
Bangs
Diamond
Catherine
Channel
Fox
Grass
Marie
Nippers ink
Petite
Pistakee

Round
Spring
Crystal
Wonder
Dawson
Bloomington
Evergreen

STORE?
Number



1751
1754
1725
1757
1758

1759




1755
1756
1727


1733




1750

1703


County
Jersey

Johnson
Knox
LaSalle
Lake
Lake
Lake

Lake
Lake
Lake
Lake
Lake
Lake
Lake
Lake
Lake
Lake
Lake,
Me Henry
Lake
McDonough
Me Henry
Me Henry
McLean
McLean
McLean,
Woodford
Nearby Town
Grafton

Buncombe
Galesburg
Somonauk
Long Lake
Antioch
Williams Park
(Island Lake)
Lake Villa
Wauconda
Mundelein
Antioch
Antioch
Fox Lake
Spring Grove
Antioch
Fox Lake
Lake Villa
Fox Lake

Round Lake
Macomb
Crystal Lake
Wonder Lake
LeRoy
Bloomington
Bloomington

Latitude
(North)
39-01-00

37-28-41
40-59-20
41-36-35
42-22-33
42-27-18
42-15-34

42-25-17
42-16-13
42-15-00
42-29-08
42-29-03
42-25-03
42-25-58
42-27-58
42-24-08
42-25-47
42-23-18

42-21-41
40-30-30
42-14-04
42-24-00
40-24-30
40-39-43
40-38-36

Longitude
(West)
90-04-15

88-56-02
90-24-30
88-39-30
88-08-10
88-04-25
88-11-20

88-05-22
88-07-46
88-00-30
88-07-04
88-08-17
88-08-28
88-09-50
88-08-18
88-10-43
88-07-39
88-12-22

88-04-33
90-43-25
88-21-27
88-20-40
88-43-30
88-56-20
89-02-30

Surface
(Hectares)
283+

48
54
133
136
66
87

115
120
60
59
129
692
598
209
240
67
829

87
112
92
295
61
257
283

Area
(Acres)
700+

118
133
328
335
163
215

284
297
149
146
318
1709
1478
516
592
165
2048

215
277
228
729
150
635
700


-------
TABLE 4.  (continued)
Serial
Number
073
074
075
076
077
078
079
080
081




082
083



085
086
087
088
089
090
091

092


Name of STORE!
Water Body Number
Decatur 1714
Carlinville
Gillespie New
Otter
Highland (Silver) 1740
Stephen A. Forbes
Central 1 a
Raccoon 1762
Marshall County
Public Hunting
& Fishing Area
(Babb, Sawyer,
Wightman)
Goose
Chain, Ingram,
Sangamon, Staf-
ford, Stewart,
Snicarte
Crane
Clear
Chautauqua
Liverpool
Matanzas
Quiver
Mermet Conserva-
tion Area
Keithsburg
National Wild-
life Refuge
County
Macon
Macoupin
Macoupin
Macoupin
Madison
Marion
Marion
Marion
Marshall




Marshall
Mason



Mason
Mason
Mason
Mason
Mason
Mason
Massac

Mercer


Nearby Town
Decatur
Carl invi lie
Gillespie
Girard
Highland
Omega
Central i a
Central i a
Lacon




Sparland




Snicarte
Liverpool
Havana
Liverpool
Havana
Havana
Mermet

Keithsburg


Latitude
(North)
39-49-30
39-14-30
39-08-20
39-24-12
38-46-05
38-43-13
38-33-24
38-32-40
41-00-53




41-15-45
—



40-07-15
40-25-00
40-22-30
40-22-10
40-15-00
40-20-08
37-15-28

—


Longitude
(West)
88-57-11
89-52-00
89-05-20
89-54-30
89-41-50
88-45-12
89-00-12
89-06-15
89-25-35




89-14-45
—



90-16-40
89-57-00
90-01-00
90-02-25
90-06-00
90-02-30
88-50-47

—


Surface
(Hectares)
1252
68
84
310
223
213
182
374
1035




526
1458+



306
592
1442
63
146
165
183

72


Area
(Acres)
3093
168
207
765
550
525
450
925
2557




1300
3600+



756
1463
3562
155
361
407
452

178


                                                    (continued)

-------
                                                 TABLE 4.  (continued)
Sft

Serial
Number
093
094
095
096
097
098
099
100
101

102
103
104
105

106
107
108
109



110
111
112
113

114


Name of STORET
Water Body Number
Swan
Coffeen 1711
Lou Yaeger 1726
Jacksonville
Mauvaise Terre
DuQuoin
Pinckneyville
New Pittsfield
Goose

Turner
Sawmill
Senachwine
Baldwin 1763

Olney East Fork
01 ney New
George
Frank Hoi ten
State Park Pond
Three (Grand
Marais)
Glen 0. Jones
Harrisburg
Springfield 1742
Pana

Shelbyville 1739


County
Mercer
Montgomery
Montgomery
Morgan
Morgan
Perry
Perry
Pike
Putnam,
Bureau
Putnam
Putnam
Putnam
Randolph,
St. Clair
Richland
Richland
Rock Island
St. Clair



Saline
Saline
Sangamon
Shelby,
Christian
Shelby,
Moultrie

Latitude Longitude
Nearby Town (North) (West)
New Boston
Coffeen
Litchfield
Jacksonville
Jacksonville
DuQuoin
Pinckneyville
Pittsfield
Henry

Granville

Henry
Baldwin

Olney
Olney
Andalusia
East St. Louis



Equal ity
Raleigh
Springfield
Pana

Shelbyville


41-14-35
39-02-15
39-11-15
39-40-15
39-42-35
38-04-00
38-06-00
--
--

41-18-47
__
41-10-00
38-12-25

38-45-08
38-47-04
41-25-11
38-34-48



37-41-00
38-50-45
39-41-14
39-21-00

39-24-30


91-03-35
89-23-45
89-35-58
90-12-45
90-12-45
89-13-30
89-24-10
--
--

89-15-00
_-
89-21-00
89-51-55

88-04-15
88-03-49
90-49-50
90-05-13



88-23-00
88-35-18
89-38-58
89-01-25

88-46-30


Surface Area
(Hectares)
49
420
514
193
70
99
67
98
1143

122
255
1346
796

379
56
68
54



43
85
1630
89

4452


(Acres)
120
1038
1269
477
172
244
165
241
2823

300
630
3324
1967

935
138
167
133



105
209
4025
220

11000

(continued)

-------
                                                TABLE 4.   (continued)
01
oo

Serial
Number
115

116
117
118
119

120

121


122
123

124
125
126
127
128
129
130
131
132

134
135
136
137


Name of STORE!
Water Body Number
Lake of the
Woods
Pekin
Worl ey
Spring
Little Grassy

Lyerla-Autumnal
Flooding
LaRue-P1ne
Hills Ecological
Area
Vermilion 1748
Washington
County
Sam Dale State
Cattail
Sunfish
Crab Orchard 1712
Devil's Kitchen
Marion
Pierce
Horseshoe 1766
Lake of Egypt

Big
Mud, Sand
Lily
Commonwealth
Edison-Dresden
Nuclear
County
Tazewel 1

Tazewel 1
Tazewel 1
Tazewell
Williamson,
Jackson
Union

Union


Vermil 1on
Washington

Wayne
Whiteside
Whiteside
Williamson
Williamson
Williamson
Winnebago
Madison
Johnson,
Williamson
Brown
Calhoun
Cass
Grundy, Will


Nearby Town
Pekin

Pekin
Pekin
Manito
Makanda

Reynoldsville

LaRue


Danville
Nashville

Johnsonville
Fulton
East Clinton
Carterville
Marion
Marion
Rockford
Granite City
Goreville

Versailles
Gilead
Beardstown
Morris


Latitude
(North)
40-35-11

40-35-00
40-35-49
40-30-59
37-38-12

--

—


40-09-24
38-16-20

38-32-29
41-51-55
--
37-43-50
37-38-06
37-40-49
42-20-55
38-41-01
37-37-15

39-58-15
39-08-12
--
41-21-30


Longitude
(West)
89-38-52

89-35-15
89-38-05
89-48-30
89-07-45

__

__


87-39-03
89-21-30

88-35-00
90-08-30
--
89-08-30
89-06-18
88-57-26
88-58-50
90-06-48
88-56-43

90-31-00
90-41-07
--
88-15-00


Surface
(Hectares)
44

43
105
520
405

105

382


246
119

79
47
72
2819
328
89
66
853
931

106
110
115
526


Area
(Acres)
108

105
259
1285
1000

259

943


608
295

194
115
178
6965
810
220
163
2107
2300

262
271
285
1300


                                                                                                   (continued)

-------
                                               TABLE 4.   (continued)
O)
10

Serial
Number
138

139

140


142

143
144
145
146
147
148
149
150
151
152
153

154
155
156
157
158
159
160
Name of STORE!
Water Body Number
Coal City
Recreation Club
Goose( Village
Club)
South Wilmington
Fireman's Beach
and Park Club
Snyder's Hunting
Club
Spring Arbor
Apple Canyon
Bracken
St. Mary's
Sand
Countryside
Crocked
Deep
Fourth
Gages
Highland
(Old Taylor's)
Zurich
Third
West Loon
Argyl e
Griswold
McCullom
Sunset
County
Grundy

Grundy

Grundy


Jackson

Jackson
Jo Daviess
Knox
Lake
Lake
Lake
Lake
Lake
Lake
Lake
Lake

Lake
Lake
Lake
McDo rough
McHenry
Me Henry
Macoupin
Nearby Town
Coal City

Morris

E, Brooklyn


Elkville

Carbondale
Apple River
Galesburg
Mundelein
Lindenhurst
Mundelein
Lake Villa
Lake Villa
Lake Villa
Graysl ake
Grayslake

Lake Zurich
Grayslake
Antioch
Colchester
Island Lake
McHenry
Girard
Latitude
(North)
__

--

—


37-54-17

37-38-48
42-26-00
40-51-30
42-16-57
42-24-33
42-15-20
42-25-22
42-55-22
42-23-27
42-21-03
42-31-47

42-11-45
42-22-31
42-27-13
40-27-15
42-17-17
42-21-42
39-26-12
Longitude
(West)
M •»

—

—


89-10-50

89-10-09
90-10-00
90-21-00
87-59-44
88-02-31
88-30-15
88-02-31
88^.04-01
88-01-29
87-59-52
88-03-52

88-06-27
88-30-47
88-05-03
90-47-30
88-13-16
88-17-32
89-51-20
Surface
(Hectares)
129

109

41


81

41
194
70
41
47
57
53
81
126
56
45

92
64
66
38
57
99
59
Area
(Acres)
318

268

101


200

100
480
172
101
115
141
130
200
310
139
110

228
157
163
95
141
245
146
                                                                                                    (continued)

-------
TABLE 4.  (continued)

Serial
Number
161
162
163
164
165

166
167
168
169
170
171
172
173
174
175

176
177
178

179
180

181
182
183

Name of
Water Body
Holiday Shores
Wild wood
Mound
Moscow
Jack, Swan,
Grass
Bath
Otter
Ki rineman
Petersburg
Fyre
Moredock
Swan
Thunderbird
Open (Marshy)
Sahara Coal
Company
Big
Long
Sugar Creek
(Curry)
Yorky
Upper Smith
(Atkinson)
Lower Smith
Powerton Cooling
Vermilion
Fishing Club
STORE!
Number County
Madison
Marshall
Mason
Mason
Mason

Mason
Mason
Mas sac
Menard
Mercer
Monroe
Putnam
Putnam
Saline
Saline

Schuyler
Schuyler
Schuyler

Schuyl er
Scott, Morgan

Scott
Tazewel 1
Vermilion

Nearby Town
Edwardsville
Vorna
Snicarte
Bath
Bath

Bath
Snicarte
Unionville
Petersburg
Sherrard
Valmeyer
Henry
Putnam
Stonefort
Carrier Mills

Frederick
Browning
Frederick

Beardstown
Naples

Naples
Pekin
Oak wood

Latitude
(North)
38-55-05
41-04-16
40-07-00
40-10-35
40-11-30

40-07-00
40-04-00
37-04-56
39-59-15
41-18-00
38-19-19
41-10-00
41-12-21
—
—

40-04-30
40-08-30
40-05-40

--
39-47-00

39-46-15
—
_-

Longitude
(West)
89-56-19
89-16-25
90-22-00
90-09-45
90-10-45

90-09-45
90-16-45
88-32-27
89-50-55
90-19-30
90-18-40
89-14-00
89-26-53
—
--

90-24-45
90-20-00
90-23-50

--
90-35-30

90-35-30
—
--

Surface
(Hectares)
174
89
140
104
673

56
117
42
77
67
55
115
46
222
47

44
45
49

188
112

51
577
43

Area
(Acres)
430
220
345
258
1662

138
289
103
191
165
135
285
113
548
115

108
111
121

465
277

125
1426
105

                                                    (continued)

-------
TABLE 4.  (continued)
Serial
Number
184
185
186
Name of
Water Body
Mesa
Little Swan
Summerset
STORE!
Number County
Wabash
Warren
Winnebago

Nearby Town
Lancaster
Avon
Durand
Latitude
(North)
38-31-43
40-40-00
42-27-10
Longitude
(West)
87-51-37
90-32-00
89-23-40
Surface
(Hectares)
41
101
115
Area
(Acres)
102
250
285

-------
Figure 31 depicts the geographic distribution of the water bodies  in a county
framework.

    NASA-Goddard experienced difficulty in generating the CCT's and was
ultimately unable to provide the CCT's for two scenes (1448-16030  and
1449-16091).  In addition, the CCT's for scene 1449-16084 arrived  without
internal calibration data; this scene was eventually dropped from
consideration.

DATA PROCESSING

Multispectral Data Processing

    LANDSAT MSS data are available from EROS in photographic and digital
(i.e.,  CCT) formats.  Data relating to lacustrine trophic state can be
extracted from both products.  However, in water-related studies the use of
digital data  is preferred to avoid the uncertainties introduced when digital
data are coded into a photographic product and then requantified through
microdensitometry.  The digital approach, selected for this project, permits
the rapid determination of picture element (pixel) counts and descriptive
statistics, and the application of a multitude of digital  image enhancement,
processing, and classification techniques.

    The LANDSAT CCT's were processed in the Image Processing Laboratory (IPL)
at NASA's Jet Propulsion Laboratory (JPL) using an IBM 360/65 and  associated
software and peripherals.  The system was operated in two modes, batch and
interactive.

MSS Data Preprocessing-
    Prior to attempting classifications of any sort, certain multispectral
data processing procedures must be implemented.  Preprocessing functions,
applied to MSS data, are employed to make corrective changes for both
cosmetic purposes and geometric reasons.  The cosmetic processing  corrects
for line dropouts, slipped or missing lines, and other obvious defects in the
imagery.  In terms of geometric corrections, the LANDSAT computer-compatible
tapes (CCT's) are not in a format compatible to the processing approaches
used in the IPL.  The CCT's, as received from the EROS Data Center, have the
data for the four MSS bands interleaved.  The IPL software program, VERTSLOG,
separates the interleaved data and creates a separate image for each band.
Next, various geometric corrections are made to compensate for mirror
velocity changes and panorama.  The data are resampled to create an
instantaneous field of view (IFOV) approximating 80 meters.  In addition, the
MSS data are expanded from seven bits of precision in the green (GRN), red
(RED),  and near infrared-one (IR1) bands, and six bits in the near
infrared-two (IR2) band, to eight bits of precision resulting in 256 digital
number  (DN) levels (0-255).

Lake Extraction Methodology—
    The primary thrust of this task is water quality monitoring and lake
classification.  The project is not concerned with land use or land-use
practices as they relate to water quality at this time. The  image-processing
                                     72

-------
                                                   LEGEND
                                                 0 Kilometers 50

                                             Water body not included in
                                             rankings and dendrograms because
                                             of faulty or missing MSS data.

                                             NES - sampled water body used in
                                             regression model development and
                                             included in rankings and dendrograms.

                                             Water body included in rankings and
                                             dendrograms.
Figure  31.
     ILLINOIS WATER BODIES

Geographic distribution  of  the  Illinois  water bodies in
a  county  framework.

-------
techniques  used  early in this  project  were  designed to extract and manipulate
MSS  pixels,  representing surface  water,  in  a batch mode of operation.  The
extraction  procedure, explained  in detail by Blackwell and Boland (1975), is
outlined below.

     Upon completion of the previously  described preprocessing functions, a
hard-copy  image  is generated from the  rescaled band 7 (IR2) data (e.g.,
Figure 24).   A candidate lake  is  selected from the scene, and a polygon is
constructed around it.  The polygon's  coordinates are input to the computer
system, and four new images, each an MSS band rendition of the subsection of
the LANDSAT scene, are generated  depicting  water body, surrounding terrain,
and a histogram  of DN values for  all of the pixels comprising the subsection
 (Figure 32).

     Through inspection, and after comparative testing, it has been determined
 that an IR2 DN value of 2"8 provides good segregation of water and land
 features.   A binary mask is developed  from  the IR2-extracted lake image by
 setting IR2 data values between 0 and  28 equal  to 1 and all  other IR2 DN
 values (29 to 255) equal to 0.  The binary mask, in which water pixel values
 equal 1 and nonwater pixel  values equal 0,  is then used to eliminate all  but
 water-related features in the  subscene.  Multiplication of each MSS band
 subsection image [4 (GRN),  5 (RED),  6  (IR1), 7  (IR2)]  pixel  by its IR2
binary-mask counterpart produces  an image for each band.   If processed
correctly,  the images will  represent only pixels containing water-related
 information.  Figure 33 is an  example  of the image produced by masking each
 subscene  image with its counterpart  IR2 binary mask.

     Some final editing is required to  eliminate rivers, streams, and other
water-related features not  considered  to be part of the lake proper.  Once
editing is  completed, listings are generated of pixel  counts, DN histograms,
and mean DN values for each band  for the entire water body, along with their
associated  standard deviations.   The water body's mean DN values (Appendix
Table A-l)  for each of the  four LANDSAT MSS spectral  bands are used for model
development  and  classification purposes.

Interactive  Lake Extraction Methodology--
     The lake extraction methodology  previously  described  was originally
designed to  handle a  relatively small  number of lakes  in a batch processing
computer mode.   The method, though accurate, was inherently slow since the
image-processing  analyst  necessarily had to wait for products before
continuing with  the next  phase of processing.  However, during the course of
this  project, the  capability for  interactive image processing at JPL's Image
Processing Lab was developed.  The  interactive system  enabled analysts
associated with this  task to develop and utilize a series of three programs
that  effectively  reduced  the time to isolate a lake, increased the accuracy
of the  water-detection  scheme, and output a statistical  and surface area
listing for  any given lake.  The  overall system is called LAKELOC.  A
detailed description of the hardware,  program operations, water-detection
algorithm, and associated outputs follows.

    Hardware--The  host computer is currently an IBM 360/65.   The display
controller used is a Ramtek G100B, a versatile  video-display device that can

                                     74

-------
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                                  tor-l» U088-49  HDG190
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                                                                                                        JPL IH«QE PCDCE'i^INIj LuEDPOTDRV
Figure  32-   GRN   RED,  IR1,  and  IR2  images  of  a LANDSAT scene  1448-16035  subscene.   The  histograms depict
               the  DN  distributions  for the subscene  including both  the  water bodies  and the land cover.
               The  large  body  is  Crab  Orchard Lake (serial  number 127) in Williamson  County.

-------
"Hvlil
 CRO! V-.tttl  •


                                                                                                  14W



                                                                                              . •
I
         M=39.15 0=2.291
                            MEAN=24.32 o=2.67|
|MEAN=17.36 0=5.331
|MEAN=6.76 o=6.33l
                                                                                                   •
     Figure 33.   GRN,  RED, IR1, and  IR2  images  of a LANDSAT scene 1448-16035  subscene after the  application
                  of the binary mask.  The  histograms depict the DN distributions for Crab Orchard  Lake
                  (serial  number 127).

-------
be used to display grey-level  images  and  graphics data.  The Ramtek is a
solid-state refresh memory system  with  a  display format of 512 lines by 640
elements.  Readback from the refresh  memory  is available under software
control.  It is possible to display six-bit  gray-level  images along with two
graphics planes, and the user may  selectively write or  erase the displays
point by point.  Manipulation of the  graphics data can  be accomplished with
the aid of a trackball  cursor. Figure  34 illustrates the configuration of
the interactive hardware as it is  arranged for the operation of the LAKELOC
program.

    Operation of LAKELOC—For the  purposes of illustration, the operation of
LAKELOC as It would be applied to  a scene in southern Illinois is described
below.  Although any number of lakes  could be extracted from a scene, this
description will be limited to one lake,  in  this case Crab Orchard Lake,
located in scene 1448-16035.

    For a given digital data scene, such  as  LANDSAT, the user may selectively
display 512-by-640 element subsections  until he locates the water body of
interest.  Automatic linear contrast  stretching of the  displayed scene can be
performed during this operation to aid  in the location  of the lake.

    Once a lake has been located,  the trackball cursor  is set on the desired
lake and a default 50-by-50 element box is drawn on the graphics plane about
the cursor position.  Figure 35 illustrates  the default box drawn about the
cursor positioned on Crab Orchard  Lake.  Since only the area within the box
will be acted on by the water detector, the  user must correct the size and
the position of the box relative to the lake so that the lake is contained
within the box boundaries.  The size  is changed by a simple command to the
program that allows the manipulation  of the  trackball cursor to control the
box dimensions.  The position of the  box  is  also controlled in the same
manner by the trackball.  Figure 36  illustrates Crab Orchard Lake completely
enclosed by the box after manipulation  of the cursor.

    Once the box has been satisfactorily  positioned about the lake
boundaries, the user is able to invoke  the water detector to isolate the
water body in a binary form.  A detailed  description of the water detector
follows  in the subsection entitled Water Detection Algorithm.   In the binary
form, the water bodies appear as white, and  nonwater features as black.  At
this time the user can magnify the area within the box  boundaries by issuing
a  "zoom" command with the appropriate magnification factor.  The zoom command
redisplays a magnified picture of  the boxed  area directly over the existing
image.  At the conclusion of the edit session, the magnified image is erased
from the screen leaving the original  image.  This allows the user to continue
uninterrupted with other lakes contained  in  the existing  scene.

    Magnification of the  image allows the user to easily determine the exact
boundaries of the lake as opposed  to  any extraneous water  information that
may also be displayed  in the scene.   Figure  37  illustrates  Crab Orchard Lake.
The detached white areas  represent extraneous  water  information that is  not
associated with the lake.  The task of  editing out extraneous pixels has been
in the  past the most time-consuming chore in the water  analysis project.
Aided only infrequently by a map,  the user must decide  what constitutes the

                                     77

-------
..
        Figure 34.  Interactive user console with video-display device and trackball.  The system is located
                   in the Jet Propulsion Laboratory's Image Processing Laboratory, Pasadena, California.

-------
boundaries of the lake in question.   Previously, the  user  relied on pixel
listings and hard-copy photographs  to locate  the lake boundaries.  In the
case of a large lake, one was often hampered  by cumbersome pixel listings
that had to be carefully pieced  together  to re-create a lake  image.  With
LAKELOC, the magnification factor,  used  in conjunction with the easily
manipulated trackball, allows the user to perform the editing task in a
matter of minutes as opposed to  a duration of several days.

    The removal of water bodies  not  associated with the lake  of interest can
be performed in two ways.  In the first method the trackball  controlled
cursor is set point by point on  the  areas to  be removed.   The default size of
the area removed is one pixel; however, the user can  specify  the number of
surrounding pixels to be removed for each erase operation.  This method  is
most useful when working in close proximity to the boundaries of the lake of
interest, where it is imperative not to  remove too large  a section of pixels
close to the lake.  The second method utilizes continuous  erasures as the
trackball cursor is moved across the screen.   The size of  the area about the
cursor position to be erased can also be  controlled by the user in this mode.
Figure 38 depicts Crab Orchard Lake after all extraneous  information has been
removed during the editing phase.

    Once the user is satisfied that  he has isolated the lake  of interest, he
assigns the lake a name and commands the  program to save  the  binary image of
the lake on a disk data set.  The lake's  position  in  the  disk data set  is
exactly the same as it is in the original LANDSAT scene.   LAKELOC returns to
the user the exact position and  size of  the extracted lake image as it
appears on the disk data set; a  parameter data set that contains this
positional information is also created.   This information is  necessary  to the
operation of the follow-on programs for  LAKELOC.  At  this time the user is
able to continue processing any  number of lakes or, if finished, to fetch the
follow-on programs that will process the statistical  data.

    Follow-on programs--The output  from  LAKELOC consists  of a binary mask
disk data set containing the extracted lakes  and a parameter  data set
containing the positional information and lake names. The output size  of the
binary disk data set is exactly  the same as the  size  of the original LANDSAT
image used as  input to LAKELOC.   In the  next  step, the binary data set  is
used by the program FARINA to mask  out of each corresponding  spectral channel
in the original LANDSAT frame the water  features that have been  processed
through LAKELOC.  The output is  four data sets containing the original  DN
values for each lake in each of  the spectral  bands.   This output can  in turn
be used as input to the program  STATUS and as input to follow-on MSS
classification programs.

    STATUS, utilizing the parameter data set  from  LAKELOC or  punched
parameter cards, produces a statistical  analysis  in the form  of  a hard-copy
listing of lake statistics  in all four spectral  channels.  The  lakes are
listed by  name and ranked according to size.   Two  tables  are  printed.   The
first  (Table 5) consists of lake statistics such as  pixel  count, surface area
calculations,  and shoreline perimeter calculations.   The  second, Table  6,
lists lake MSS statistics,  such  as the mean DN level  for  each lake  in  each
spectral channel, and the corresponding  standard deviations.

                                     79

-------
Figure 35.  Crab Orchard  Lake  with
default 50-by-50 element  box.   This
is a subsection of  scene  1448-16035
(October 14, 1973).
Figure 36.   Crab  Orchard  Lake
contained within  correctly
positioned box.
 Figure 37.   Crab  Orchard  Lake  in
 binary form  (with magnification
 factor of 2)  before  editing  of
 extraneous water  information.
Figure 38.  Crab Orchard Lake in
final, edited form.

-------
                  TABLE 5.   AREAL  STATISTICS FOR EXAMPLE  LAKES*
   ** LAKE  NAME **
                   *** LAKE STATISTICS ***

** TOTAL PIXELS **      **  SURFACE AREA **
              SQUARE FEET      ACRES    HECTARES
 ** SHORELINE **
FEET       METERS
Plnckneyville 99
OuQuoin 98
Washington Co 123
Devil's Kitchen 128
Little Grassy 119
Cedar 39
Egypt 132
Klnkald 40
Crab Orchard 127
Rend 29
59
74
103
338
547
855
1121
1267
4027
10694
4064451.0
5097786.0
7095567.0
23284432.0
37682283,0
58900095.0
77224569.0
87282363.0
277416003.0
736698966.0
93.3
117.0
162.9
534.5
865.1
1352.2
1772.8
2003.7
6368.6
16912.2
37.8
47.4
65.9
216.3
350.1
547.2
717.4
810.9
2577.3
6844.1
11650.1
17379.6
31260.7
84010.2
101302.8
161456.4
240158.9
239724.2
363440.0
583720.1
3550.8
5297.0
9527.8
25605.1
39875.6
49209.5
73196.9
73064.4
110771.1
177909.3
•Computer-generated table.
                 TABLE  6.  MSS DN STATISTICS  FOR EXAMPLE LAKES*
      LAKE NAME
                          WEEN
                 *** LAKE MSS STATISTICS ***
               ** MEAN **              *       ** STANDARD DEVIATION **
              RED      IR1      IR2   *   GREEN     RED     IR1     IR2
PlnckneyvUle 99
DuQuoin 98
Washington Co 123
Devil's Kitchen 128
Little Grassy 119
Cedar 39
Egypt 132
Kinkaid 40
Crab Orchard 127
Rend 29
45.03
35.04
40.63
33.12
36.83
34.68
38.27
35.89
38.84
40.50
28.71
18.28
27.75
16.12
18.60
19.15
22.81
18.94
23.69
26.73
23.71
19.22
25.39
17.38
16.98
17.80
20.06
17.58
20.82
19.87
11.36
9.88
13.42
9.89
9.08
9.16
10.92
9.68
8.13
7.03
2.75
2.33
5.93
1.78
2.54
2.51
3.68
3.00
3.11
5.46
2.23
2.03
8.53
1.86
2.52
3.00
3.50
3.65
3.47
6.51
5.86
5.92
8.98
6.80
6.74
6.38
7.83
7.30
6.37
7.49
6.65
6.44
7.81
7.89
7.86
7.54
9.10
7.77
6.40
6.11
•Computer-generated table.
                                             81

-------
    Water detection algorithm -- In the past,  the detection  of  pixels whose
instantaneous field of view (IFOV)  is  that  of  water was  done in the
straightforward manner of thresholding band 7  (IR2)  as described previously.
The low reflectance of water in this spectral  range conveniently produced  a
bimodal distribution of DN's — one peak for water, another  peak for
nonwater.  This technique works quite  well  except in the case where the  IFOV
of the scanner is viewing a combination of  water and nonwater areas such as
the shoreline of a lake or where cloud shadows straddle  the  water-land
interface.  In this situation, the problem  becomes one of trying to estimate
the proportion of each material in the IFOV.

    Horowitz et al. (1971) and Work and Gilmer (1976) have investigated  the
proportion-estimation problem with encouraging results.   Work and Gilmer have
estimated the proportions of water, bare soils, and green vegetation  using
LANDSAT bands 5 and 7.  This technique requires an estimate  of  the spectral
signature for pure water, pure bare soil, and  pure vegetation.   While the
spectral signature of water is fairly  easy  to  estimate,  that for soil and
vegetation becomes more difficult.  The many variables  involved, such as
different soil types, vegetative cover types,  and thickness  of  the vegetative
cover, cause considerable error when estimation is attempted by a completely
automatic processor.

    An alternate approach, and the one chosen  for implementation, considers
the mixture classes to be only water and nonwater.  Bands 5 (RED) and 7  (IR2)
are used in the detection process; bands 4  (GRN) and 6 (IR1) offer little
additional information.  The estimation of  the spectral  signature for water
and nonwater is made over a region within,  and immediately surrounding,  the
water body.

    The spectral signatures (mean DN values) are estimated by an iterative
procedure.  First, the two-dimensional space (band 5 vs. band 7) is
partitioned into two regions in which the populations of water and nonwater
typically cluster.  The mean is then recomputed for those DN's  that  fall
within a neighborhood of the initial mean.   This process is continued until  a
convergent mean has been found for each region.

    The proportion estimation that was implemented uses a technique proposed
by McCloy (1977).  In Figure 39, W is the mean for water, U is the mean  for
nonwater, and P is the DN for any given pixel.  P' is the projection  of  P
onto the line segment WU.  If /WU/ is the length of the line segment  WU, and
/WP1/ is the length of line segment WP1, then  the proportion estimate q  for
water is:
where

    0 4q 41

If P1 does not fall between W and U, it is given the position of the closest
point, W or U.  A decision threshold is set for q at which the pixel is
defined to be water or nonwater.

                                     82

-------
                  CO
                  00
                               P1
                                  Band 5
   Figure 39.   Geometric interpretation  of  the water-detection algorithm.


    Both the batch and interactive modes of lake extraction  provide the user
with MSS data related to the specific  water bodies  under  consideration.  For
this project, the band averages for each lake were  used,  a consequence of
several factors including time and cost.

    Average spectral  responses for each  band for all  pixels  in a  lake do not
account for the variability of responses for a specific portion of a lake and
its associated optical properties.  Thus, lake characterization using average
spectral responses for each band demonstrates the average lake response and
not the variation actually measured.  An examination  of LANDSAT DN-level
histograms for all study lakes supports  the idea that lakes, as viewed by the
MSS, are heterogeneous bodies.  For example, Figure 40 illustrates the
nonhomogeneous nature of Cedar Lake (serial number  55).   Although this aspect
of lakes is recognized, data extraction  and subsequent analyses largely
utilized a "whole lake" concept by using band values  averaged over all the
lake pixels.  This technique provides  a  general  spectral  response for a given
lake but does not differentiate between  extreme  readings  within a wavelength
band, nor does it demonstrate precise  variations  in spectral composition.

    The data for each of the project lakes  in a  LANDSAT scene were treated  in
this manner.  After final editing, the IR2  images of  lakes from a particular
scene were concatenated into one or two  photographs (Figures 41-48).   In
general, side overlap water bodies, those found  in  LANDSAT scenes of two
consecutive dates (e.g., October 14 and  15), appear in only  one
concatenation.  Forward overlap water  bodies, those found in the  10 percent
forward overlap area of two scenes of  the same  date (e.g., Sawmill Lake
(serial number 103) in scenes 1449-16082 and 1449-16084), were only extracted
from one scene and appear in only one  concatenation.
                                     83

-------
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                                                      DN Level
51  5  10 15  20  25  30
        DN Level
Figure 40.   LANDSAT MSS  histograms of four bands of Cedar Lake (serial  number 55).   The data  were
            extracted  from  scene  1448-16023.

-------
                                                             CHTHEPINE
                                                             CHHHMEL
                                                             MnPIE
                                                             GRASS
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                                                             THIRD
       20      23     149
Figure 41.   IR2 concatenation  of 33 Illinois  water bodies extracted from
              LANDSAT  scene 1448-16023  (October 14,  1973).
                                           85

-------
            I I I I I 1 ( I I ( I I I I I ( I ( I I I t I 1 I > > I I I ( I I 1 1 I I 1 I I I I I  I I I t I I I I I I 1 I I I 1 I t I 1 I I I I i I I I I
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       15   PARADISE
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       13   LINCOLN TRAIL STATE PARt-
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       1£4  SAM DALE STATE
LANBSAT FRAME 1448-1603E
ILLINOIS LAKE PROJECT
JPL EPA
12 LAKES EXTRACTED
;TRETCH
   [PL   PIC    D  77/05XS1/13EQ34I
                    JPL IMAGE PROCESSING LABORATORY
  Figure 42.  IR2 concatenation of 12  Illinois water bodies extracted from
            LANDSAT scene 1448-16032  (October 14, 1973).  See Figure 18
            for 20 more lakes extracted from the scene.
                                  86

-------
                                                             CH&PLEITDH
                                                             PAP^BILE
                                                             MATTDDM
                                                             LIMCDLH TPt,IL ITATE
Figure 43.   IR2 concatenation of  20 Illinois water bodies  extracted from
             LANDSAT scene 1448-16032 (October  14, 1973).   See Figure  17.
                                       87

-------
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127
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                                              :UMMERSET
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                                              AND CLUE
                                              IiEPUE
                                              TURNER
                                              GDQ:E
                                              :AU MILL
                                              :UAN
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                                              :ENACHWINE
Figure 45.   IR2 concatenation of 20  Illinois water bodies extracted
             from LANDSAT  scene 1449-16082 (October 15, 1973).
                                   89

-------
                                                                 UILDUQOD
                                                                 GOO IE
                                                                 UOPLE .-'
                                                                  WKE or THE uani
                                                                 PEKDI
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                                                                 EIO
                                                                 DTTEP
                                                                 Dull' DM
                                                                 PETEP1EUPG
                                                                 EVEPGPEED
                                                                 ELQQnltiGTDtl
Figure  46.  IR2 concatenation of 35  Illinois water bodies extracted from LAND-
             SAT scene 1449-16084 (October  15, 1973).  The CCT's  for this scene
             were supplied without  the necessary  internal  calibration  data.

-------
                                   1£1  LA RUE-PINE HILLS
                                        ECOLOGICAL
                                        HORSESHOE
          121
        FRAME  1449-16093
                                   8    SPRING
                                   144  APPLE CANYON
                                        CATTAIL
                                        SUNFISH
                                   108  LAKE GEORGE
                                   170  FYRE
                                   93   SMAN
   186     108    170    93

         FRAME  1450-16140
Figure 47.  IR2 concatenation of nine Illinois water bodies  extracted
          from LANDSAT scenes 1449-16093 (October 15, 1973) and
          1450-16140 (October 16, 1973).
                            91

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                                        KETHSBURG NUR
                                        BRACKEN
                                        LITTLE SHAH
                                        SPRING
                                        APGYLE
                                        BIG
                                        tCU  PITTlFIELIi
                                        UPRER SMITH
                                        LDUEP SMITH
                                        LILY
                                        SfcMGAMDIS  CONSEPVATIDr
Figure 48.   IR2 concatenation  of 13 Illinois  water bodies extracted
             from LANDSAT  scene 1450-16142  (October 16, 1973).
                                   92

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Milltispectral  Data  Adjustment

    Complete multispectral  scanner  data  coverage for  Illinois requires
overlapping the data from three  passes of  the  satellite, as shown earlier in
Figure 19.   Thus, the raw data set  consists of three  subsets that are defined
by the orbit during which the  information  was  gathered.  This stratification
in the raw data set required that certain  transformations be effected to
create a single, unified, date-independent base that  could be used for
further analyses.

    To accomplish this restructuring, use  is made of  the fact that lakes on
the eastern and western edges  of the scenes (i.e., side overlap lakes) appear
on successive  passes.  Thus, within the  larger data set, there are two
subsets —  the October 14 and  15 overlap and the October 15 and 16 overlap.

    It appears reasonable,  from  an  examination of the operation of the
satellite,  the multispectral scanner, and  the  resultant data, to expect that
the raw data pairs  for the  side  overlap  lakes  represent the sum of small
random and systematic effects.  If  the effects are almost entirely random,
they will  be reflected in any  statistical  adjustments as increases in the
errors of estimation.  Although  systematic effects can contribute both
additively and multipl icatively, multiplicative effects should be minimized
by calibration of the MSS.   Thus, it appeared  reasonable, both from
consideration  of the processes involved  in generating the data and from
plotting side  overlap data  pairs, that simple  linear  relationships could be
established for each of the four bands and for each of the two pairs of
dates.

    The models that were developed  are presented in Table 7.  As expected,
the slopes are close to 1.00,  the relationship being  better for the 14th to
15th conversion than for the 16th to 15th.  This may  be largely the result of
the greater number  of degrees  of freedom available for the former estimates.

    Data from  scene 1449-16084 could not be used in developing these models
because there  were  no internal calibration data found with it.  This was
unfortunate since a substantial  number of  lakes that  might have been included
in developing  the models could not  be used because their overlap on the 15th
was on this unusable scene. Attempts to develop an internal calibration for
this scene were unsuccessful.  Unfortunately,  we learned this after extensive
efforts to develop  meaningful  clusters based on spectral data, and attempts
to develop models relating  spectral and  chemical data, failed.

    Using these models, a data base consisting of 14th and 16th data adjusted
to the 15th, and raw 15th data,  was prepared.  Duplicates in the data base
arising from the overlap lakes were removed, retaining original 15th data in
preference to  calculated values, except  for scene 1449-16084 where only
calculated values were used.  For this latter  reason, seven lakes
(Bloomington,  Springfield,  Sanghris, Dawson, Evergreen, Goose (Sparland), and
Wildwood)  appearing in scene 1449-16084  could  not be  incorporated into the
final data set.  The raw and final  sets  are presented in Appendix Table A-l.
                                     93

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TABLE 7.   REGRESSION MODELS USED TO ADJUST MULTISPECTRAL  SCANNER DATA FOR OCTOBER 14
          AND 16 TO OCTOBER 15,  1973

Dependent
Variable
Models for
GRN15
RED15
IR115
IR215
Models for
GRN15
RED15
IR115
IR215
Regression
Constant
Adjusting the
0.5580
-1.1481
0.9823
1.6842
Adjusting the
12.4990
6.3859
7.6123
3.5378
Regression
Coefficient
October 14th
0.9683
1.0161
0.9473
0.8822
October 16th
0.7291
0.7781
0.6159
0.6340
Independent
Variable
Data
GRN14
RED14
IR114
IR214
Data
GRN16
RED16
IR116
IR216
R2

0.8226
0.9279
0.9221
0.9210

0.9445
0.9918
0.9464
0.8652
Standard
Error of
Regression

2.0807
1.2853
1.0811
0.8931

0.6952
0.4725
0.8927
0.7306
Degrees of
Freedom:
Regression,
Residual

1,13
1,13
1,13
1,13

1,5
1.5
1,5
1,3

-------
Trophic Indices Development

    A multiplicity of classificatory schemes has evolved to group and  rank
lakes.  Examples of some approaches to lake typology are found  in Lueschow
et al.  (1970), Rawson (1956, 1960), Margalef (1958), Hansen (1962),
Jarnefelt (1958), Larkin and Northcote (1958), Moyle (1945, 1946), Pennak
(1958), Round (1958), Whipple (1898), Winner (1972), Zafar (1959), Beeton
(1965), Donaldson (1969), Uttormark and Wall (1975), Gerd (1957), and  Taylor
et al . (in press).  Hutchinson (1957, 1967) has reviewed many of the attempts
to arrange lakes into orderly systems.  The term "classification" is often
used in the restricted sense of placing entities into distinct  groups,
thereby excluding arrangements showing no distinct division (e.g.,
ordination).  The term is used here in the broader context suggested by
Sneath and Sokal (1973) and includes ordination.

     Lacustrine trophic state is a multidimensional  concept and amenable to
analysis by multivariate statistical techniques (e.g., cluster  analysis,
principal component analysis).  Multivariate techniques minimize the personal
bias often present when data are examined for groups and rankings are
developed.  They are of particular value in situations where large numbers of
objects or parameters are to be classified.  Principal components analysis
can be used to develop trophic state indices.

    Principal components analysis, an ordination technique, may be used to
reduce the dimensionality of a multivariate system by representing the
original attributes as functions of themselves.  The main object is to
summarize most of the variance in the system with a lesser number of
"artificial" va Mates (i.e., principal components).

    The computation of principal components can be undertaken using either a
covariance matrix (S) or a p x p matrix of Pearson product-moment correlation
coefficients (r).  Use of the r-matrix is indicated when the variates  are
measured in different units (e.g., grams and meters).  Computation of  the
r-matrix principal components involves the extraction of eigenvalues
(characteristic or latent roots) and eigenvectors (characteristic or latent
vectors).  The eigenvalues are a set of p nonzero, positive, scalar
quantities.  The sum of the eigenvalues of the r-matrix is the  trace of the
matrix, which is equal to the number of dimensions in the original system
(i.e., the number of variates, p).  The rank of the matrix is equal to p.

    Normalized eigenvectors give the attribute-space (A-space)  coordinates
of an orthogonal set of axes known as the principal  axes.  The  normalized
eigenvectors are comonly designated as principal components. The first
principal component of the observations of the p-variates Xi,...,Xp is
the linear compound

                        Yj  =  alj xl + ••• + apj x
                         j      lj  l   •••    pj   p

whose coefficients are the elements of the eigenvector associated with the
jth largest eigenvalue extracted from the r-matrix.  The jth eigenvalue is a
measure of the variance of the jth principal  component.


                                     95

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     The proportion  of the total sample variance in the cloud of dimensionless
 standard scores  attributable to any component is found by dividing its
 eigenvalue  by  p.  The first principal component has the innate property of
 explaining  the greatest proportion of the sample variance with each
 successive  component explaining progressively smaller amounts of the total
 sample  variance.  Frequently, a consequence of the decreasing order of the
 variance is that K  < p dimensions will adequately summarize the variability
 of the  original  variates, Xi,...,Xp.  The first three components
 generally account for most of the variation, thereby permitting the
 ordination  of  the subjects in one-, two-, and three-dimensional (3-D) space.
 All  of  the  dispersion in the data can be accounted for by using p dimensions,
 but  this negates the analysis objective, which is the reduction of
 dimensionality or,  as Seal (1964) stated, the "... parsimonious summarization
 of a mass of observations."

     The  principal components of N p-variate observations are defined
 geometrically  as "... the new variates specified by the axes of a rigid
 rotation of the original response coordinate system into an orientation
 corresponding  to the directions of maximum variance in the sample scatter
 configuration" (Morrison 1967). The normalized eigenvectors give the
 directions  of  the new orthogonal axes, and the eigenvalues determine the
 lengths  (i.e., variance) of their respective axes.  The coordinate system is
 expressed in standard units (zero mean, unit variance) when the components
 are  extracted  from the r-matrix.  Figure 49 is a hypothetical bivariate
 example  of  the geometrical meaning of principal  components.  Detailed
 descriptions of the theoretical and computational  aspects of principal
 components  are found in Hotelling (1933a, 1933b, 1936), Anderson (1958), and
 Morrison (1967).

     Principal  components analysis was used to develop two trophic indices for
 the  31  Illinois water bodies sampled by the National  Eutrophication Survey.
 The  first index (PC1F5)  uses the fall  sampling values (Appendix Table A-2)
 for  five trophic indicators:   CHLA, ISEC, COND,  TPHOS, and TON.  The second
 index (PC1Y5)   is generated using sampling-year mean values (Appendix Table
 A-3)  for the same trophic indicators.   The same methodology was employed in
 the  development of both  indices.  The methodology is  briefly explained below
 using the fall  trophic index generation for illustrative purposes.   The raw
 trophic  indicator data (Appendix Tables A-2 and  A-3)  for the 31 NES-sampled
 lakes are skewed and were, therefore,  natural  log (LN) -transformed  to give a
 distribution more closely approximating a normal  one.   The transformed
 indicator data are identified as LNCHLA,  LNISEC,  LNCOND,  LNTPHOS, and LNTON.
 The data matrix was further standardized  by attributes  using the relationship
where

    z  =  standardized value for attribute i  of observation j  (i.e.,  lake)

  *ij  -  LN-transformed value of attribute i  of observation j


                                     96

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                FIRST PRINCIPAL AXIS
                CORRESPONDING TO THE
                FIRST PRINCIPAL
                COMPONENT S
                                           SECOND  PRINCIPAL AXIS
                                           CORRESPONDING TO  THE
                                           SECOND  COMPONENT S
                                   CHLOROPHYLL a (X,J
     Figure 49.  Geometrical interpretation of the principal components
                 for a hypothetical bivariate system.


    Principal components may be interpreted geometrically as the variates
corresponding to the orthogonal principal axes of observation scatter in
A-space.  The elements of the first normalized eigenvector  (i.e.,
coefficients of the first principal component) define the axis that passes
through the direction of maximum variance in the scatter of observations.
The associated eigenvalue corresponds to the length of the first principal
axis and estimates the dispersion along it.  The second principal component
corresponds to the second principal axis, the length of which represents the
maximum variance in that direction.  In our example, the first component
accounts for most of the dispersion in the data swarm, and the original
2-dimensional system could be summarized in one dimension with little loss of
information.  The new variate value (PCI) for each lake is obtained by
evaluating the first component

                              Y!  =  aXj + bX2

The PCI for each lake in one-dimensional A-space is its coordinate on the
first component axis, which is shown diagrammatically by projecting each
observation to the principal axis  (modified from Brezonik and Shannon 1971).
                                     97

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   x-j  =  the mean of attribute i

   s.j  =  standard deviation  of attribute  i.

Eigenvectors and eigenvalues  were  then  extracted  from the associated
correlation matrix (Table 8)  and displayed in  Table 9.   Next, the  first
normalized eigenvector was evaluated for. each  of  the 31  lakes,  resulting in
31 trophic index (PC1F5)  values, one for each  water body.   The  PC1F5 value
defines a water body's position on the  first principal axis.  The  correlation
coefficients, eigenvectors, and eigenvalues for the sampling-year  trophic
index (PC1Y5) are found in Tables  10 and 11, respectively.  The resultant
trophic index values for the  31 NES water  bodies  are found  in Table 12.


 TABLE 8.  R-MODE PEARSON PRODUCT-MOMENT CORRELATION MATRIX OF  FIVE TROPHIC
           STATE INDICATORS*
CHLA
(LNCHLA)
CHLA 1.000
(LNCHLA) (1.000)
COND
(LNCOND)
ISEC
(LNISEC)
TPHOS
(LNTPHOS)
TON
(LNTON)
COND
(LNCOND)
0.219
(0.405)
1.000
(1.000)






ISEC
(LNISEC)
0.242
(0.479)
0.142
(0.124)
1.000
(1.000)




TPHOS
(UVTPHOS)
0.649
(0.593)
0.596
(0.459)
0.444
(0.641)
1.000
(1.000)


TON
(LNTON)
0.827
(0.758)
0.327
(0.400)
0.370
(0.407)
0.836
(0.771)
1.000
(1.000)
Correlations computed using mean data values of the fall  sampling period for
31 NES-sampled water bodies.  Numeric values  enclosed by parentheses are
correlation coefficients for natural  log-transformed data.


    Index values for 145 Illinois lakes were  calculated from regression
models developed from 22 of the NES lakes (LANDSAT data were available for
only 22 NES lakes).  In these models  the trophic indices,  derived from
principal components analyses, were taken as  the dependent  variables and the
LANDSAT MSS bands (or some variation  thereof) were the independent variables.
The data for the 22 NES lakes were used to develop the models.   These models,
found in "Trophic Indicator and Index Estimation" were then used to estimate
trophic state index values for the entire set of 145 lakes.
                                     98

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                                TABLE 9.   NORMALIZED EIGENVECTORS AND EIGENVALUES*
ID

Eigenvector
Number
1
2
3
4
5

LNCHLA
0.480
0.029
0.470
0.642
-0.368

LNCOND
0.325
0.764
-0.504
0.181
0.156

LNISEC
0.385
-0.634
-0.505
0.297
0.327

LNTPHOS
0.513
-0.099
-0.208
-0.570
-0.599

LNTON
0.502
0.065
0.476
-0.377
0.612

Eigenvalue
3.085
0.887
0.557
0.363
0.108
57000
Variance
(%)
61.70
17.74
11-. 14
7.26
2.16

Cumulative
Variance
(%)
61.70
79.44
90.58
97.84
100.00


     *Eigenvalues and eigenvectors calculated from correlation matrix values based on trophic indicator
      data collected during the fall sampling period from 31 water bodies.

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TABLE 10.   R-MODE PEARSON  PRODUCT-MOMENT  CORRELATION MATRIX OF FIVE TROPHIC
           STATE INDICATORS*
CHLA
(LNCHLA)
CHLA 1.000
(LNCHLA) (1.000)
COND
(LNCOND)
ISEC
(LNISEC)
TPHOS
(LNTPHOS)
TON
(LNTON)
COND
(LNCOND)
0.382
(0.439)
1.000
(1.000)






ISEC
(LNISEC)
0.292
(0.412)
0.028
(-0.033)
1.000
(1.000)




TPHOS
(LNTPHOS)
0.559
(0.622)
0.422
(0.254)
0.443
(0.699)
1.000
(1.000)


TON
(LNTON)
0.937
(0.807)
0.360
(0.399)
0.275
(0.312)
0.652
(0.699)
1.000
(1.000)
Correlations computed using sampling year-mean values for 31 NES-sampled
 water bodies.  Numeric values in parentheses are correlation coefficients
 for the natural log-transformed data.


    All of the computational aspects of trophic state index development were
executed on a Control Data Corporation digital computer (CDC 3300)  at Oregon
State University using the Statistical Interactive Programming System (SIPS).
A  detailed explanation of SIPS and its operation is found in Guthrie et al.
(1973).

Surface Area Estimation

    The nominal size of a LANDSAT-1 MSS pixel is 57 meters by 79 meters,
resulting  in an areal coverage of 0.4503 hectares per pixel.  As indicated
earlier in this study, the surface area of a water body is defined by pixels
having IR2 levels  of 28 or less.  The total surface area of a water body is
calculated by  summing the number of  pixels having DN values within the above
range  (Appendix Table A-l) and then  multiplying by the appropriate conversion
factor.  During the CCT preprocessing phase, the MSS data were resampled,
resulting  in pixels having nominal edge measurements of 80 m and an area of
0.6400 ha.  The value of 0.6400 was  used as the multiplication factor to
convert water  body IR2 pixel summations to surface area in hectares (Appendix
Table  A-l).

     Side overlap  coverage (October 14 and  15, October 15 and 16) was
 available  for  22  Illinois water bodies.  This self-pairing situation
 permitted  the  comparison of  surface  area estimates derived from LANDSAT data
 collected  on consecutive days.


                                     100

-------
                                TABLE 11.  NORMALIZED EIGENVECTORS AND EIGENVALUES*
o

Eigenvector
Number
1
2
3
4
5
LNCHLA
0.519
0.182
-0.278
-0.630
-0.473
LNCOND
0.269
0.703
0.639
0.002
0.160
LNISEC
0.375
-0.617
0.434
-0.362
0.399
LNTPHOS
0.514
-0.258
0.166
0.639
-0.483
LNTON
0.504
0.160
-0.546
0.253
0.598
Eigenvalue
2.926
1.127
0.562
0.265
0.120
5.000
Variance
(%)
58.52
22.54
11.24
5.30
2.40
Cumulative
Variance
(%)
58.52
81.06
97.30
97.60
100.00

     *Eigenvalues and eigenvectors calculated form correlation  matrix  values based on sampling-year
      trophic indicator mean values for 31 water bodies.

-------
  TABLE 12.  TROPHIC STATE INDICES AND RANKINGS FOR 31 NES-SAMPLED  ILLINOIS
             WATER BODIES
Name of Water
Body
Baldwin
Bloomington
Carlyle*
Cedar*
Charleston*
Coffeen
Crab Orchard*
Decatur*
DePue*
East Loon*
Fox*
Grass*
Highland-Silver
Holiday*
Horseshoe
Long*
Lou Yaeger
Mari e*
Old Ben Mine*
Pistakee*
Raccoon*
Rend*
Sangchris
Shelbyville*
S locum*
Springfield
Storey*
Vandal ia*
Vermilion
We-Ma-Tuk*
Wonder*
Serial
Number
105
71
14
55
16
94
127
73
3
53
60
61
77
51
131
52
95
62
32
65
80
29
11
114
54
112
50
27
122
33
69
PCIF5
-1.74
-1.00
-0.78
-2.67
0.78
-2.52
-0.22
-0.51
2.61
-0.55
0.67
1.71
-1.76
0.86
1.31
2.59
-1.38
1.43
2.38
1.52
-1.01
-1.19
-1.89
-1.35
4.56
-1.21
-0.47
-1.13
-0.09
-1.33
2.33
(Rank)
( 5)
(13)
(14)
( 1)
(21)
( 2)
(18)
(16)
(30)
(15)
(20)
(26)
( 4)
(22)
(23)
(29)
( 6)
(24)
(28)
(25)
(12)
(10)
( 3)
( 7)
(31)
( 9)
(17)
(11)
(19)
( 8)
(27)
PCIY5
-2.00
-1.30
-0.90
-2.89
0.02
-2.55
0.14
-0.17
2.41
-0.77
1.68
1.84
-0.77
1.22
2.43
1.98
-0.77
0.33
1.55
1.63
-0.48
-1.13
-1.48
-1.62
4.31
-1.09
-1.07
-1.32
-0.16
-1.35
2.29
(Rank)
( 3)
( 8)
(12)
( 1)
(19)
( 2)
(20)
(17)
(29)
(15)
(25)
(26)
(13)
(22)
(30)
(27)
(14)
(21)
(23)
(24)
(16)
( 9
( 5)
( 4
(31)
(10)
(11)
( 7)
(18)
1 6)
(28)
NES
504
296
345
528
225
454
347
201
139
399
212
244
229
247
313
195
241
303
240
253
330
442
369
339
210
283
333
323
227
367
183
(Rank)
( 2)
(16)
( 9)
( 1)
(25)
( 3)
( 8)
(28)
(31)
( 5)
(26)
(20)
(23)
(19)
(14)
(29)
(21)
(15)
(22)
(18)
(12)
( 4)
( 6)
(10)
(27)
(17)
(11)
(13)
(24)
\ /
( 7)
\ /
(30)
*Used in the development of regression models for the estimation of trophic
 state using LANDSAT MSS bands as the independent variables.
                                    102

-------
DATA ANALYSIS APPROACH

    Regression and cluster analysis are two  techniques that were employed to
explore the relationships suspected to  exist between and within the remotely
sensed and contact-sensed data sets.

Regression Analysis

    MSS data presented as false-color or gray-scale  imagery provide immediate
visual recognition, not only of structural features such as water bodies,
land surfaces, and vegetation, but  also of gradations within and between such
features.  Expressed as spectral  density histograms, information is derived
about the evenness of the distribution  of reflected radiation, without regard
to the spatial distribution of the  features  giving rise to the pattern.
Using clustering techniques, which  will  be described later, items such as
lakes may be conveniently grouped together in physically significant ways
solely on the basis of their reflectance patterns.  All of these techniques
need to utilize only the information inherent in the MSS data themselves to
produce significant results.

    In environmental monitoring studies such as this on lake trophic state,
MSS data by themselves are of limited use.   Rather, the scientist needs to
use this readily available data to  estimate  physical, chemical, and
biological parameters in lakes.  To make these estimates, regressions are
developed from a set of lakes for which concurrent contact-sensed and MSS
data are available.

    Regression is a statistical term describing the relationship of a
dependent variable (Y) to one or more independent variables (X).  Regression
has many uses.  In converting MSS data  from  the 14th or 16th of October to
the 15th, for example, regression was used to effect a change of scale.
Regression was also used to develop predictors or estimators of Y, for given
values of X, as described below.

    While several statistical methods for developing regression models exist,
least-squares analysis is most commonly employed.  According to Snedecor and
Cochran (1967), three assumptions are made about the relation between Y and X
in univariate models.  First, for each  value of X there is a normal
distribution of Y from which a sample value  of Y is taken at random.  Second,
the population of Y's corresponding to  the selected value of X has a mean p,
which lies on the straight line

                               u.. ..  =   a +  BX
where x  =  X - X

            the value of the population mean corresponding  to x  =  0
a

3
            the slope of the line which is  the  incremental  change in Y per
            unit change in X.
                                    103

-------
 Third,  the  standard deviation, ffy.x, of Y about the mean is the same for
 all  values  of  Y.   Then

                              Y  =  a + px + «

 where  « =   a  random variable drawn from normal population with mean 0 and
             standard deviation 
-------
    Next, the actual  models were developed  by  stepwise multiple regression
using the date-corrected MSS bands  as  independent variables and trophic
indicators and trophic indices  as dependent variables.  (A large number of
"new" independent and dependent variables,  "created" through a variety of
techniques (e.g., log transformation,  ratios,  standardization), were examined
during the modeling effort.) The regression was usually carried about two
stages above that of maximum change in the  multiple correlation coefficient
(R) or its square (R2).   At this point the  regression was backstepped until
the most parsimonious model was reached.   Selection of a particular model was
made after an examination of the multiple correlation coefficient, mean
residual square, significance of the regression and individual regression
coefficients, number of  independent variables, and scatter in the residuals
for several models.  A thorough discussion  of  the analysis and selection of
variables in multiple regression is available  in Hocking (1976).

    Regressions were developed  using the Statistical Interactive Programming
Systan (SIPS) on a CDC 3300 digital  computer located at Oregon State
University (Rowe and Barnes 1976).   With the particular regression subsystem
used, it was discovered  that the last-added independent variable was not
necessarily the first removed in the backstepping mode (Hocking 1976).  The
subsystem was consistent in generating a particular model  in this fashion,
and the statistics for the chosen model could  be confirmed by independent
calculation.  The three  sets of models in Table 15 were developed in this
manner.  These models were used to  estimate the values of trophic indicators
and trophic indices for 145 Illinois water  bodies.  The estimated values were
then used to rank the 145 water bodies.

Cluster Analysis

    Boesch (1977) has recently  written an  excellent review of the application
of numerical classification in ecological  investigations of water pollution.
Excerpts from his description of numerical  classification are given below:

    "In simplest terms,  classification is  the  ordering of  entities
    into groups or sets  on the basis of the relationships of  their
    attributes.  Classification is  an important biological process
    which must predate man, but the science of classification has
    had a fairly recent  and parallel development  in several dis-
    ciplines (Sokal 1974)....

    "Numerical classification ojr cluster analysis  encompasses a
    wide variety of techniques for  ordering entities  into  groups
    on the basis of certain formal  pre-established  criteria rather
    than on subjective and undefined conceptions.   Numerical  classi-
    fications have certain advantages over subjective  classifica-
    tions, notably:   (1) they can be based on  a much larger number
    of attributes than  is allowed by human mental  capacity; and  ('2)
    once the classificatory criteria are set,  their results are
    repeatable by any investigator studying the same data  set.
                                    105

-------
"It is important to distinguish classification from several
other processes and analyses.   First, the process of "identi-
fication," involving the allocation of additional unidentified
entities to the most appropriate class, once such classes have
been established (Dagnelie 1971, Sneath and Sokal 1973, Sokal
1974), is excluded from classification. ... The optimal
splitting of a continuous into a discontinuous series
(Clifford and Stephenson 1975), is here considered a case of
classification.  Secondly, various multivariate analyses other
than numerical classification may be applied to ecological
data.  These include, in addition to various regression and
correlation approaches, a broad group of techniques known as
ordination.  In ordination the relationships among entities
are expressed in a simplified spatial model of few dimensions,
with no attempt to group or draw boundaries between classes
(Pielou 1969, Whittaker 1967, Whittaker and Gaich 1973, Sneath
and Sokal 1973, Orloci 1975).  Ordination includes such
techniques as principal components analysis, factor analysis,
principal coordinates analysis, correspondence analysis, and
multidimensional scaling.

"To orient the reader ..., a brief description of the chain of
procedures in numerical classification is in order.  Numerical
classifications are generally directed by a set of algebra-
ically expressed criteria (an algorithm).  This chain of opera-
tions begins with the original data, in one or more forms which
may be further transformed to conform to certain preconditions.
In ecological applications the original data are generally in
the form of a matrix of some measure of abundance of each
species in a series of collections (See Figure 50).

"From the original or transformed data matrix most numerical
classifications then require the computation of a resemblance
measure between all pairs of entities being classified.  This
is a numerical expression of the degree of similarity, or,
conversely, dissimilarity, between the entities on the basis
of their attributes.   In ecology, the entities being classi-
fied may be collections (representing sites, stations, or
temporal intervals) with species content as the attributes.
This may be referred to as a normal classification as opposed
to an inverse  classification of species as entities with
their presence or abundance in the collections as attributes
(Williams and Lambert 1961).   'Normal' or  'inverse' are  syn-
onymous with the widely used terms 'Q analysis' and  'R
analysis', respectively.  However, the Q/R distinction has
been confused in the past (Ivimey-Cook, Proctor, and Wigston
1969) and the normal/inverse inverse terminology is fast
becoming standard in ecology....
                                  106

-------
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      Classification J
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Figure 50.   Sequence of  procedures in  numerical classification (modified
             from Boesch  1977).  (The  Illinois water bodies were classified
             using LANDSAT MSS bands or LANDSAT estimated trophic indicators
             as "species", i.e., attributes).
                                      107

-------
    "Matrices of inter-entity resemblance measures  are usually re-
    quired to perform normal  or inverse analyses.   These matrices
    are symmetrical  in that one corner is the mirror image of the
    other across the 'self-match'  diagonal  and thus it is
    necessary to display only half of the matrix,  ... as the
    excluded portion is repetitous.... From the resemblance
    matrix one can go further and  seek to group entities into
    groups on the basis of their patterns of resemblance....This
    is the essence of clustering.

Many clustering concepts and methods are described  in the literature (Sneath
and Sokal 1973, Anderberg 1973).  Although algorithms have been developed for
many clustering methods, the investigator is often  forced to select  from a
very limited number because he lacks access to computers with the  necessary
operational software.  In biological studies, the most commonly employed
strategies for finding clusters are those that can  be described by the
acronym SAHN (sequential, agglomerative, hierarchic, nonoverlapping) (Sneath
and Sokal 1973).  Several SAHN clustering methods  are found in Table 13.


                   TABLE 13.  SOME SAHN CLUSTERING  METHODS*


Cluster Method                                          Synonyms


Single linkage                                       Nearest neighbor
                                                     Minimum method

Complete linkage                                     Furthest neighbor
                                                     Maximum method

Average linkage
    Arithmetic average
         Unweighted (UPGMA)                          Group average
         Weighted (WPGMA)

    Centroid
         Unweighted centroid                         Centroid
         Weighted centroid                           Median


*Adapted from Sneath and Sokal 1973


    The complete linkage (also called maximum or furthest neighbor)  method of
clustering was selected for this project, primarily on the basis of
availability.  The complete linkage method may be described as an exclusive,
intrinsic, hierachicals agglomerative, combinatorial approach to clustering
(Figure 51).
                                     108

-------
        I
NONEXCLUSIVE         EXCLUSIVE
           	I
           I
      EXTRINSIC                           INTRINSIC
                                                                  I
                               HIERARCHICAL            NONHIERARCHICAL
                                                                  I
                           DIVISIVE  AGGLOMERATIVE  SERIAL     SIMULTANEOUS
                               |                I     OPTIMIZATION  OPTIMIZATION

                MONOTHETIC  POLYTHETIC  J


                              COMBINATORIAL     NON-COMBINATORIAL
    Figure 51.  Dichotomized scheme depicting the salient properties of clustering methods (modified
              from Boesch 1977 and Williams 1971).  Complete linkage properties are interconnected
              by the arrow-defined pathway.

-------
    Although this report  will  not  detail the above description of the
complete linkage method  (see Sneath  and Sokal 1973, Boesch 1977, Anderberg
1973), it bears mentioning  that the  process  is one of progressive fusions.
Clustering proceeds "...by  forming one cluster for each observation in the
analysis.  The two closest  clusters  are combined  into one cluster, then the
two closest of the new set  of  clusters are combined into a cluster, and so
forth.... The distance between two clusters  is defined to be the maximum
distance between an observation in one cluster and an observation in the
other cluster" (Barr et  al. 1976).

    Squared Euclidian distance (A2)  was selected  as the resemblance measure
(dissimilarity coefficient) between  lakes.   As with the clustering method,
selection was made on the basis of availability.  When working in an
attribute space (A-space) of p orthogonal dimensions, Euclidian distance is
the linear distance between any pair of entities  (e.g., lakes) in that space.
The distance between two  entities  is computed as  the square root of the sum
of the squared differences  of  the  entity-paired attribute values
where Ajk  =  Euclidian distance between lake J  and K

      X-jj  =  the value of the ith attribute for lake J

      Xjk  =  the value of the ith attribute for lake K

        p  =  the number of attributes.

If two entities are identical  in terms of their  attributes, they will occupy
the same position in p-dimensional A-space  and the Euclidian distance between
them will be zero.  As the distance between entities increases, the disparity
between them increases (Sneath and Sokal  1973).   Distance  is the complement
of similarity.

    The use of Euclidian distance (or its square) as a measure of resemblence
has much intuitive appeal.  It is relatively easy to grasp through the use of
algebraic and geometric techniques (Figure  52).   Recalling from geometry that
the Pythagorean theorem for right triangles states that the square of the
length of the hypotenuse is equal to the sum of  the squares of the lengths of
the two remaining sides, or (using the  notation  in the upper part of Figure
52)

                                C2  =  a2 + b2

it follows that the length of the hypotenuse (distance between Point A and
Point B) may be defined as
                                     110

-------
   (8
   
-------
    Using different notation (lower  portion of Figure 52), the Pythagorean
theorem is extended to  two  lakes, A  and B, whose locations in two-dimensional
attribute space (A-space) are defined by the coordinate pairs Ui,a,
X2 a)  and (Xi  K» X2 b)» respectively.  The squared Euclidian distance
between the tikes mly be described as


                  *ab2   '  Ixl,a-Xl,bl2+  Ix2,a-X2,bl2


where |   | refers to "absolute magnitude" and  is employed to eliminate the
use of negative distances.   The  squaring of differences also ultimately
eliminates the negative distance aspect and thus the equation may be
rewritten as:

                  *ab2   -  (xl,a - xl,b>2 +  a - X2jb)2


The Euclidian distance  (Aab) between the two lakes  is described by
and will either have or lack units depending  upon  which  preclustering
procedures are used.  If, for example,  the  attribute data  in  the data matrix
were standardized (mean of zero,  unit variance), the Euclidian distance would
be dimensionless.  On the other hand, using the LANDSAT  MSS bands as the
attributes and foregoing transformations  and  standardizations (i.e., using
MSS band raw data), the Euclidian distance  would be measured  in digital
number  (DN) levels.

    Figure 53 illustrates the geometric aspects of three lakes (A, B, and C)
in three-dimensional A-space.  In this  case squared Euclidian distance
between Lake A and Lake B is computed as

and                            Aab   =  U^)


     It is difficult to visualize the geometry of four-dimensional  A-space and
it can not be depicted graphically because of the orthogonal  axes
requirement.  However, it is possible to extend most geometric theorems of
three-dimensional spa^e to p dimensions in Euclidian hyperspace; this  can be
demonstrated algebraically (Sneath and Sokal  1973).  Thus, the Euclidian
distance dissimilarity measure is not limited to three dimensions  by
theoretical constraints.
                                     112

-------
                                                   Lake Coordinates
                                                          /arX2,a, X3/a)
                                                           b  X2/b, X3(C)
                                                       (X1rC/ X2/c, X3/c)
                     2 _
                                     (X2,a -
(X3.a -
                       = (Aab2)V2
Figure 53.   Geometric  and computational aspects of Euclidian distance  between
            three  entities  (i.e., lakes) defined by coordinates in three-
            dimensional  attribute space (A-space).  [In this example,  the
            attributes are  three LANDSAT bands (GRN, RED, IR1).  The
            attributes could be three trophic indicators (e.g., chlorophyll
            a^,  Seech i  depth, total phosphorus) (adapted from Boesch 1977 and
            Ineath and Sokal 1973).]
                                    113

-------
    As indicated earlier, the complete linkage clustering method was  employed
using squared Euclidian distance as  the measure of  resemblance.  The  U-k2)
sequence of procedures is illustrated in Figure 54.  While many
clustering "runs" were made, only the results  for two,  made on 145  Illinois
water bodies in A-space, will be interpreted in the discussion in Section  7
of this report.  These runs are:

    1.   Four-band LANDSAT clustering -- A-space of four dimensions defined
         by LANDSAT GRN, RED, IR1, and IR2 bands.   Date-adjusted MSS  data
         were used without standardization or transformation.

    2.   LANDSAT-estimated four trophic indicator clustering — A-space of
         four dimensions defined by the trophic indicators CHLA, TPHOS, TON,
         and SEC.  Trophic indicator values were estimated from regression
         models developed from LANDSAT MSS-trophic  indicator relationships
         elucidated for 22 NES-sampled lakes.   The  values for each  trophic
         indicator were standardized (mean of zero, unit variance)  prior
         to the computation of the resemblance matrix.

    The actual clustering was accomplished using two different computer
programs.  The first program, CLUSTER, was developed by Barr et al.
(1976) as part of the SAS 76 statistics program package.  It uses the
clustering scheme described by Johnson (1967).  The cluster "map"  generated
by the program was found to be physically bulky, difficult to  visually
interpret, and thus unsuitable for inclusion in this report.  Fortunately,
this program also generates a listing of the clusters and their respective
members.  A second program (also called CLUSTER) rewritten by Keniston from
programs by Keniston, Faruqui, and Carkin (Keniston 1978) was used  to
generate products (e.g., dendrograms or phenograms) of a more desirable
nature.  This program was run on a Control Data Corporation (CDC)  CYBER 73
digital computer at Oregon State University.  The  dendrograms were  then
generated on a Gerber Model 1000 flatbed plotter,  an "off-line" device, using
the tape output from the CYBER 73.

    The outputs of a clustering program represent  an attempt to simplify
.complex data sets.  Numerical classification per se does not provide  an
ecological interpretation of the products.  Post-clustering analyses  aimed at
the interpretation of the dendrograms are presented in Section  7  of this
report.
                                     114

-------
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Figure 54.  Sequence of procedures as applied to the  numerical

            classification of  Illinois water bodies.
                              115

-------
                                  SECTION 7


                           RESULTS AND DISCUSSION
    As Indicated in Section 1,  the basic objective of this project  was  to
classify, in the broad sense of the term, Illinois lakes and reservoirs as to
trophic state.  It was the original intention to include all Illinois lentic
bodies with surface areas equal  to or greater than 40 ha.  This would have
included the 31 NES-sampled lakes.  A combination of circumstances  (e.g.,
cloud cover, missing or defective MSS data)  resulted in dropping
approximately 40 of the proposed 179 lakes.   The decrease in the number was
partially offset by the inclusion of several  water bodies with surface areas
under 40 ha.  The end resglt was the use of 22 NES-sampled water bodies in
the development of the regression models.  Rankings and classes were
generated for 145 Illinois water bodies, including the 22 sampled by NES.
Subsequent subsections of this  section will  discuss the results.

WATER BODY SURFACE AREA

    Surface area estimates were made for 153 Illinois water bodies  (Appendix
Table A-l) including those found in scene 1449-16084, the scene without
internal calibration data.  As  evidenced by Appendix Table A-l, side overlap
lakes have two LANDSAT-derived  area estimates, one for each consecutive day
of satellite coverage.  Two questions immediately come to mind:  How precise
are the consecutive day area estimates?  How accurate are the estimated area
values?  Table 14 was prepared  in response to these questions.  The lakes
included in this table are those for which side overlap coverage was
available, excluding those from scene 1449-16084.  Lake Senachwine was not
included in the statistical calculations because its area estimate for
October 16, 1973, is less than  optimal, a consequence of a portion of the
lake falling outside scene 1450-16140.

    An indication of the precision of LANDSAT MSS-derived area estimates can
be gained by examining the self-pairing estimates made for 21 water bodies.
Ideally, the consecutive-day estimates for a particular water body would be
the same, and indeed this is the case for three water bodies:  Commonwealth
Edison-Dresden Nuclear Lake (serial number 137), Lake Pinckneyville (serial
number 99), and Snyders Hunting Club Lake (serial number 142).  The
difference between the self-paired estimates was computed as  (A-B) where A is
the area estimate of'October 14 or 16 and B is the estimate of October 15.
The mean difference for the water bodies is 0 ha with a sample standard
deviation of  13 ha.  The correspondence between the estimates A and B is very
good, as demonstrated by Figure 55 and the area ratios  (A/B)  in Table 14.

                                      116

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TABLE 14.  COMPARISON OF SURFACE AREA ESTIMATES  FOR 22  ILLINOIS WATER BODIES
           HAVING LANDSAT SIDE OVERLAP COVERAGE  (OCTOBER  14 AND 15 OR
           OCTOBER 15 AND 16, 1973)
Area Estimates (ha)
LANDSAT Date File*

Name
Carbondale
Cedar**
Commonwealth
DeQuoln
Goose t
Goose (Village)
Kinkaid
McGinnis
Murphy sboro
Pierce
Pinckneyville
Saganashkee
Senachwine f
Skokie Lagoons
Snyders Hunting
South Wilmington
Spring
Spring Arbor
Summerset
Tampier
Thunderbi rd
Sum
Mean
Standard Error
of Mean
Maximum Value
Minimum Value
Range
Sample Standard
Deviation
Serial
Number
38
39
137
98
101
139
40
20
37
130
99
21
1 t\A
11)4
22
142
140
4
143
186
23
173








14th or
(A)
29
72
460
55
741
74
855
114
47
60
49
146
1 Of\Q
ItU?
80
17
99
137
15
94
90
38
3510
167
51

855
15
840


16th 15th
(B)
27
77
460
52
696
75
876
102
54
58
49
167
i cm
loUo
84
17
101
135
17
92
94
42
3505
167
50

876
17
859


(C)
55
728
526
99
1143
109
1093
127
58
66
67
132
1 1Ad
U*tO
76
81
41
106
41
115
66
45
4258
213
73

1143
41
1102


Area
(A-B)
+ 2
- 5
0
+ 3
+45
- 1
-21
+12
- 7
+ 2
0
-21
- 4
0
- 2
+ 2
- 2
2
- 4
- 4
0
3

45
-21
66
13

Differences
(A-C)
- 26

- 66
- 44
-402
- 35
-238
- 13
- 11
- 6
- 18
+ 14
+ 4
- 64
+ 58
+ 31
- 26
- 21
+ 24
- 7
- 40
23

58
-402
460
104

(B-C)
- 28

- 66
- 47
-447
- 34
-217
- 25
- 4
- 8
- 18
+ 35
+ 8
- 64
+ 60
+ 29
- 24
- 23
+ 28
- 3
- 42
25

60
-447
507
111




Area Ratios
(A/B)
1.07
0.94
1.00
1.06
1.07
0.99
0.98
1.12
0.87
1.03
1.00
0.87
0.95
1.00
0.98
1.02
0.88
1.02
0.96
0.91
0.99
0.02

1.12
0.87
0.25
0.07

(A/C)
0.53

0.88
0.56
0.65
0.68
0.78
0.90
0.81
0.91
0.73
1.11
1.05
0.21
2.42
1.29
0.37
0.82
1.36
0.84
0.90
0.10

2.41
0.21
2.21
0.46

(B/C)
0.49

0.88
0.52
0.61
0.69
0.80
0.80
0.93
0.88
0.73
1.26
1.11
0.21
2.46
1.27
0.42
0.80
1.42
0.93
0.92
0.10

2.46
0.21
2.25
0.47

 *  Surface area values taken from I EPA data files.
 ** Cedar Lake was just filling in 1973.  The file value is for 1977.   The
    lake is not included in the calculations.
  t Goose Lake (101) area difference (A-B) exceeds the sample standard
    deviation by more than three times.
  t Senachwine (104) surface area data not included in calculations because
    a portion falls outside scene 1450-16140.
                                     117

-------
                       900
                       800
                    
                     U
                       300
                       200
                        100
                                                                                             • 40
                                          Line of 1:1 Correspondence
                                       Serial Number and Name
                                           3  Depue
                                           4  Spring
                                          20  McGinnis
                                          21  Saganashkee
                                          22  Skokie Lagoons
                                          23  Tampier
                                          37  Murphysboro
                                          38  Carbondale
                                          39  Cedar
                                          40  Kinkaid
                                          98  Duquoin
                                          99  Pinckneyville
                                         101  Goose
                                         130  Pierce
                                         137  Commonwealth
                                         139  Goose (Village Club)
                                         140  South Wilmington
                                         142  Snyder Hunting
                                         143  Spring Arbor
                                         173  Thunderbird
                                         186  Summerset
                                 100
200
                                                 300
                                                        400
                       500
600
700
                                                                                       800
                                                     900
                                          Surface Area Estimate of October 15 (ha)
          Figure  55.  LANDSAT-derived consecutive-day  surface  area estimates  for 21  Illinois water bodies,

-------
The line in Figure 55 is defined by the ideal  area  ratio of  1:1;  it  is  not a
regression line generated from area data for the 21 water bodies.   If the two
area estimates for a particular water body are the  same, the point
representing the values would fall  somewhere on the line. With a few
exceptions, the points fall  on or very close to the line. The area  ratios
(A/B) for several  lakes are a source of some concern;  these  include  McGinnis
(1.12), Murphysboro (0.87), and Saganashkee (0.87).  Assuming that the  areal
discrepancies are not a consequence of heavy rains  or drawdown, several
factors may be responsible for the variation in the estimates.

    One such factor, probably the prime one, is atmospheric  variability.
Atmospheric path radiance can change markedly from  one day to the next.  For
example, the intrinsic (independent of atmosphere)  radiance  may be the  same
for a lake for two consecutive LANDSAT flyovers. However, as viewed through
the atmosphere by the satellite, the lake may exhibit an apparent change in
its intrinsic radiance, a consequence of a change in path radiance.  As path
radiance increases, the apparent intrinsic radiance of most  lakes will
increase and the converse is also true.  Thus, the  DN values for  the pixels
representing a lake and surrounding terrain may change from  day to  day.  As
given previously, an IR2 level of 28 was used as the threshold between  land
and water features.  If a pixel has an IR2 DN value of 0 to  28, inclusive, it
was classified as water; if 29 to 255, it was labeled as nonwater.   The IR2
DN threshold of 28 was treated as a rigid boundary.  Increases in path
radiance could result in an apparent emigration of  pixels across the
boundary, effectively reducing the number of pixels in the IR2 0  to  28  DN
group defined as water.  Decreases in path radiance could result  in  the
immigration of more pixels to the IR2 0 to 28 DN group, leading to  a larger
surface area estimate.

    In situations where water bodies are in juxtaposition and have  poorly
defined natural boundaries (e.g., flowages and backwaters),  the judgment of
the computer operator becomes the critical factor in separating the  water
bodies.  In this case, the operator defines the location of  the common
boundary.  He is not always able to duplicate the boundary's location  in
successive imagery.  The situation is further complicated by maps that  give
conflicting locations for the boundary or, and this is more  common,  only name
the bodies, leaving the map reader the task of defining boundaries.  The
common boundary problem can lead to different surface area estimates.

    Illinois reservoirs tend to be long and narrow, with highly developed
shoreline configurations (numerous fingers and bays).  With  so much
land-water interface (Lake Sangchris, for example,  has more  than  160 km of
shoreline), a substantial number of pixels will contain both land and  water
features.  In many cases the land portion of the pixel may contribute  enough
energy to shift the pixel DN value above the water  threshold. This could
lead to an underestimation of lake surface area.

    The accuracy of LANDSAT-derived area estimates  is another point  of prime
concern.  This concern can be best addressed by examining the LANDSAT  area
values in light of estimates derived from other time-proven  techniques (e.g.,
aerial photography, surveying) employed concurrently with the LANDSAT
flyover.  The concurrent aspect of the contact-sensed data is important


                                     119

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because lentic bodies are dynamic  and  can experience substantial changes in
surface area.  Prolonged  dry  spells, drawdown, large quantities of
precipitation, outlet downcutting, flow control structures, and landfill
projects can produce changes  in surface area.  Even in the case of concurrent
acquisition of surface area data,  the  problem of defining the water-land
interface exists.   It would appear that defining the boundary of a lentic
body on an aerial  photograph  or through survey is an easy task, and in some
cases it is. However, more often the task of locating the interface is
complicated by the presence of marshes or swamps that grade into a lake over
distance.  Where to "draw the line" becomes a problem that is left to the
judgment of the photo interpreter,  cartographer, or surveyor.  Once this
determination has been made and the requisite computations performed, an area
estimate is entered into  a data file.  It is important to recognize the
limitation of surface area figures taken  from files.

    Given the historical  nature of this project — NES sampled the water
bodies prior to the formulation of the project protocol -- surface-area data
were not readily available.  This  severely handicapped the project in making
a detailed analysis of the accuracy of LANDSAT-derived surface estimates.
However, realizing its limitations, a  comparison was made using surface area
figures taken from IEPA files (Table 14). For reservoirs, in most cases, the
file values are estimates of  the surface  area at spillway level at the time
of construction.  However, in many cases  the surface area at the spillway
level has probably changed over time because of shoreline erosion,
sedimentation, and other  factors.   Pool level elevations are not available
for October 1973.   An examination  of Table 14 and accompanying Figures
56 and 57 suggests that the LANDSAT-derived values tend, on the average, to
underestimate the IEPA values.  A  lot  of  scatter is apparent about the 1:1
line of correspondence.  Hence, data of sufficient quality are not available
to determine how well LANDSAT data, as processed, estimate the surface area
of Illinois lakes.

     It may well be that the LANDSAT area  values are underestimates.  Boland
and  Blackwell (1978), reporting on a study involving several Colorado lakes,
indicate that LANDSAT area estimates were, on the average, about 1.2 percent
under those estimated from concurrently acquired aerial photographs (N = 8).
The  Colorado data do not, however, prove  that LANDSAT underestimates the
surface area of Illinois  water bodies.

     The selection of the  IR2  DN level  of  28 as the water-land threshold value
was made based on past experience  and  its intuitive appeal; it  is a simple
approach.  As suggested by Blackwell and  Boland (1978), it may be more
appropriate to use the technique (or some variation) proposed by McCloy
(1977).  This technique,  discussed in  Section 6, may result in more precise
and  accurate estimates of surface  area.

TROPHIC  INDICATOR AND INDEX ESTIMATION

     In order to obtain estimates of four  trophic  indicators (CHLA, SEC, TON,
and  TPHOS) and two multivariate trophic  indices (PC1F5, PC1Y5) using LANDSAT
MSS  spectral data, three sets of multiple regression models were developed
(Table 15).  Initially, regressions were  developed for the indicators and

                                     120

-------
                900 r
                800
             I
             <0 700
             r-  600
             w
             flJ
             .O
             o
             W  500
             "5
             5
             CD  400
rv>
             w
             UJ
             8
             •g
             3
             0)
                300
200
                100
                                                                                                       40
                                                                                          101
                                                                                           •
                                           137
                                                                Line of 1:1 Correspondence
Serial Number and Name
   3  Depue
   4  Spring
  20  McGinnis
  21  Saganashkee
  22  Skokie Lagoons
  23  Tampier
  37  Murphysboro
  38  Carbondale
  40  Kinkaid
  98  Duquoin
  99  Pinckneyville
101  Goose
130  Pierce
137  Commonwealth
139  Goose (Village Club)
140  South Wilmington
142  Snyder Hunting
143  Spring Arbor
173  Thunderbird
186  Summerset
                          100     200    300     400     500    600     700     800    900
                                           Surface Area Estimate From IEPA Files (ha)
                                                                              1000    1100   1200
         Figure  56.   Comparison of  October 14 and  16 LANDSAT-derived surface area  estimates with  IEPA file
                      values for 20  Illinois water  bodies.

-------
ro
ro
                900
                800
             2  700
                600
                500
                400
                300
                200
                100
                      140 ~ A •'••
                        130  " *1"
                      v»i»A,r
                     X**3"*1."
                                                                                                           A
                                                                                                           101
Line of 1:1 Correspondence
       Number and Name
       Depue
       Spring
       McGinnis
       Saganashkee
       Skokie Lagoons
       Tampier
       Murphysboro
       Carbondale
       Kinkaid
       Duquoin
       Pinckneyville
       Goose
       Pierce
       Commonwealth
       Goose (Village Club)
       South Wilmington
       Snyder Hunting
       Spring Arbor
       Thunderbird
       Summerset
                          100     200     300     400    500     600     700    800     900

                                            Surface Area  Estimate From IEPA Files (ha)
                    1000
1100
                                   1200
          Figure  57.  Comparison of  October  15, 1973,  LANDSAT-derived  surface  area estimates with IEPA  file
                       values for 20  Illinois  water bodies.

-------
     TABLE  15.   THREE  SETS  OF  REGRESSION  MODELS  FOR  THE  ESTIMATION  OF  TROPHIC  INDICATORS  AND  MULTIVARIATE
                 TROPHIC  STATE  INDICES
                            Model
                                                         Degrees
                                                           of
                                                         Freedom
Calculated
  F-Value
                                                                                             100
        Standard
        Error of
        Estimate
                       Set  One:   Models  based  on  LANDSAT  MSS  spectral  bands  and  band  ratios

                                                                              9.55         74.90
GJ
SEC   =  -26.206 - 0.610 * GRN + 0.939 * RED + 17.246 *    5,16
         GRNRED + 1.276 * REDIR1 - 0.827 * IR1IR2

CHLA  =  EXP (37.337 + 0.476 * GRN - 0.922 * RED           5,15
         -15.327 * GRNRED -8.079 * REDIR1 + 1.922 *
         REDIR2)

TON   =  [(X * X-l.)  **2./ (4. * X * X)] where X is:      4,17
         -2.023 - 0.223 * GRN + 0.325 * IR1 + 3.117 *
         GRNRED + 0.826 * REDIR2

TPHOS =  |EXP[EXP (6.202 - 0.076 * IR1 -2.293 * GRNIR1 +   3,18
         0.244 * GRNIR2)](/100.

PC1F5 =  (12.279 - 0.177 * IR1 - 4.631 * GRNIR1 + 0.572 *  3,18
         GRNIR2) **2.-3.

PC1Y5 =  12.782 - 0.193 * IR1 - 5.017 * GRNIR1 + 0.701 *   3,18
         GRNIR2) **2. -3.
 22.30



 25.16



 18.74


 30.46


 39.32
88.14



85.55



75.75


83.54


86.76
                          0.31
                                                                                                      0.31
                                                                                                      0.71
                                                                                                  (continued)

-------
                                TABLE 15.  (continued)

Model
Degrees
of Calculated
Freedom F-Value
R2X
100
Standard
Error of
Estimate
Set Two: Models based on normalized LANDSAT spectral bands
SEC =

CHLA =

TON =
TPHOS =

PC1F5 =

PC1Y5 =
EXP[EXP (1.396 - 0.234 * SIR1 - 1.198 * LNSRED
+ 0.227 * SGRN + 0.200 * SIR2)] /100.
[-34.677 - 12.735 * SIR1 - 16.209 * LNSIR2 -
5.304 * RED + 94.014 * LNSIR1]**2.
|EXP[EXP(8.796 + 0.087 * SIR1 - 4.522 * RTSGRN
+ 0.647 * SGRN - 0.042 * SIR2)]|/100.
[1.173 + 1.407 * LNSIR1 - 1.682 * LNSGRN +
5.371 * RTSIR2 - 5.176 * LNSIR2]**5.
79.188 + 19.827 * LNSIR1 - 48.892 * SQRTSGRN +
5.399 * SGRN - 7.459 * LNSIR2
-10.922 - 5.041 * SIR1 - 9.384 * LNSIR2 - 2.276
4,17

4,17

4,17
4,17

4,17

4,17
72.6

80.2

70.4
73.7

81.2

87.6
0.33

28.91

0.34
0.16

0.80

0.61
* SGRN + 44.592 * LNSIR1
                                                                                    (continued)

-------
                                                TABLE 15.  (continued)
IX)
en
Degrees Standard
Model of Calculated &K Error of
Freedom F-Value 100 Estimate

SEC =
+ 0.006
CHLA =
TON =
TPHOS =
PC1F5 =
PC1Y5 =
Set Three: Models based on lake LANDSAT spectral
JEXP[EXP(1.552 - 0.006 * REDRK + 0.003 * IR2RK 4,17
* GRNRK - 0.005 * IR1RK)]|/100.
[2.147 - 0.011 * GRNRK - 0.010 * IR2RK + 0.008 4,17
* RAT100 + 0.017 **IR1RK] **5.
)EXP[EXP(1.263 + 0.002 * IR1RK - 0.001 * GRNRK 3,18
- 0.001 * IR2RK) **2.]f/100.
(0.697 + 0.005 * IR1RK - 0.003 * GRNRK - 0.001 3,18
* IR2RK) **5.
0.264 + 0.076 * IR1RK -0.043 * GRNRK - 0.030 * 3,18
IR2RK
0.304 + 0.076 * IR1RK - 0.040 * GRNRK- 0.038 3,18
ranks
59.0
74.0
62.5 0.39
61.1 0.20
65.3 1.04
64.6 1.03
              *  IR2RK

-------
multivariate indices using contact-sensed and raw spectral data available
from 22 NES-sampled lakes.   In developing these models  (Set One, Table 15)
using stepwise regression, additional variates were created by taking the
ratios of bands  (i.e., green band to red band, GRNRED).  The use of such
ratios has precedent in  similar studies  (e.g., Boland 1976).  While the
models gave every appearance of having practical utility (e.g., high RS
low standard error of estimate, good estimates of indicator and index
values), when they were  applied to the full set of 145  lakes major
inconsistencies  appeared.  The inconsistencies were particularly obvious when
the estimated values of  the  four trophic indicators for the 145 lakes were
aggregated into  a combined or composite  rank for each lake and a list was
generated displaying the lakes in ascending order of eutrophication.

    To create this  list, the estimated value for each trophic indicator
 (CHLA, TON, SEC, TPHOS)  was  replaced by  its rank value.  The rank values for
the four  indicators were summed to give  a grand value for each of the 145
 lakes, which were then ranked in ascending order according to the magnitude
 of the grand value.  An  examination of this list disclosed several seriously
 misclassified lakes.  For example, Lake  Calumet, a highly polluted water
 body,  appeared  near the  top  (best) of the list.  These  reversals were
 suspected to be  the result of at least four causes.

     First, although efforts  were made to normalize the  dependent  (trophic
 indicator or multivariate index) parameter in developing the regression
 models,  no effort was made to do this for the spectral  data.  This was not
 deemed important since,  with the exception of the IR2,  the bands  showed an
 approximately normal distribution of data, with skew and kurtosis of about
 0.0  and  3.0, respectively.

     Second, although the IR2 band has the poorest discrimination, and the
 lowest information  content of any of the bands, it weighed consistently and
 heavily  in all  of the models.  When this band was excluded, the resulting
 models were statistically unsatisfactory.  Thus, we are faced with the
 paradox  of a poorly resolved factor contributing significantly to the
 predictive power of the  regressions.  Since, in at least some of  the cases
 (e.g., Calumet), the  IR2 intensity did not appear to vary to the  extent or
 direction of the other bands, that is, did not  increase as water  quality
 deteriorated, the highly significant  IR2 values would contribute  nonlinearly
 to the estimates.

    Third, it was recognized that the ratios used in developing the models
 contributed nonlinear components to the  regressions.  This effect, coupled
with  the  nonlinearity contributed by the IR2, resulted  in  "linear" models
 with  nonlinear  components.   Alternatively, the  effect may be viewed as that
 of a  p-dimensional  plane operating in a  nonorthogonal or  bivalued
 p-dimensional hyperspace; that is, the model is a linear  hyperplane cutting
 both  curved and  linear spaces.

    Fourth, the  spectral data for the subset of 22 water  bodies used to
 develop the models  cover a narrow range  in relation to  that  of the full set
of 145.   Thus, while the models appear to operate well  for lakes  within this
narrow band, they have very  poor discrimination outside these limits.

                                     126

-------
    Whether the failure to afford reasonable extrapolations is inherent  in
the data, as discussed above, or in the models, as suggested here,  is  moot
since no simple corrections for these effects are apparent.  Consequently,
the project is constrained by these models to estimate trophic indicator and
multivariate trophic index values only for lakes with LANDSAT MSS data that
fall within the range of those for the 22-lake subset or to develop other
models as will now be discussed.

    In developing new models, it was imperative that the information about
the full range of the whole set be included in the subset used for  developing
the regressions.  To accomplish this, the spectral data for the subset were
standardized by dividing each observation by the standard deviation for  that
band for the entire set of 145.  The models (Set Two, Table 15) that were
developed using standardized spectral data gave better estimates of trophic
indicator and index values for the subset of 22 than did those constructed
from the raw spectral data.  Further, the estimates for the full set showed
few reversals or non-linearities.

    At least two problems were apparent with some of the individual trophic
indicator and index estimates made from Set Two models.  First, these  models
generated negative values for lakes with LANDSAT spectral data either  much
higher or much lower than the regression set, for Secchi and chlorophyll a,
and total organic nitrogen and total phosphorus respectively.  Unreasonably
high estimates of Secchi depth were obtained from very low (or for  the other
indicators, for very high) spectral data values.

    Trophic indicator estimates made for the 145 water bodies from  the second
set of models, when converted to ranks, gave ordered lists which were  in
reasonable agreement with expectation.  Clusters developed from the estimated
trophic indicator values appeared to have physical significance in  that  the
clusters could be sequenced in a rough hierachy of trophic condition.

    The third set of models was developed using data ranks in place of raw  or
normalized spectral data.  To create the regression models (Set Three, Table
15), the normalized spectral data for the 145 lakes were sequenced  in
ascending order, and ranks were then assigned to each value for each of  the
four bands.  Next the spectral ranks for the 22 NES lakes were extracted from
the set of 145 and used to develop the third set of models defining
statistical relationships between the remotely sensed data and ground  truth.
For Secchi depth, total organic nitrogen, and total phosphorus, highly
significant correlations were developed using combinations of the  four sets
of ranked spectral data.  Chlorophyll a^ presented a problem, however,  in that
this technique afforded statistically significant, but 'physically
unimportant, models with poor predictive power.  Careful examination of  the
results from the other models, clustering results from spectral data,  and
consideration of the interactions occurring between chlorophyll a_ and  the
high sediment loads present in many Illinois lakes suggested that  some
spectral ratio of the LANDSAT IR1 or IR2 and the red and green bands might
make a statistically significant contribution to the model for chlorophyll  a..
For these reasons two ratios were developed, one between the RED and IR1
bands and the other, subsequently named RAT100, between the GRN and IR2
bands.  The former was statistically insignificant when included as a

                                     127

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regression variable, while the latter was highly significant.  The use of the
variable RAT100, defined as  (GRNRK + IR2RK) /  (GRNRK - IR2RK -1.), where
GRNRK and IR2RK are a lake's rank for the set  of 145, caused mathematical
problems for Diamond Lake (serial number 57) and potential problems for Grass
Lake (serial number 61), Swan Lake (serial number 93), and Pierce Lake
(serial number 130).  For the first lake the denominator of the ratio was
zero, while for the other three  it was either  plus or minus 1, indicating
that GRNRK = IR2RK.  For these four lakes RAT100 was assigned a value of
zero.

    Trophic indicator and multivariate trophic index estimates generated from
the Set Three models are in  general agreement  with the contact-sensed data
for the 22 NES lakes (Table  16).  The descriptive statistics for the actual
and predicted values are in  (subjectively) close agreement, thereby
indicating that the models are capable of reproducing population, as well as
point,  information.  The 95  percent confidence limits of the predicted values
for the 22 NES lakes used in developing the Set Three regression models are
within the range of the sample values (Table 17).  These confidence limits
are those obtained for each  estimated point.   They are not the same, being
broader, as the standard error about the mean  of the dependent variable.

    The trophic indicator and index estimates  for the full set of 145
 Illinois lakes developed from the Set Three models are found in Appendix
 Table  A-4. The population statistics for the full set are  (subjectively) in
 agreement with those of the  subset of NES lakes (Table 18).  This is
 important for two  reasons.   First, it demonstrates that the NES lakes
 comprise a random  subset; that is, they adequately reflect the variability of
 the  population.  Second, unlike  the previous models (Sets One and Two), the
 predictive equations are essentially linear over the data range.  Therefore,
 meaningful extrapolations can be made from the Set Three models.

    While it is possible to  gauge the accuracy of the trophic indicator and
multivariate index estimates for the 22 NES lakes through an examination of
the models' residuals, the necessary concurrent contact-sensed data are not
available for the  remaining  123  lakes, thereby preventing a similar
comparison.  However, the estimates for the full set appear to be
 "reasonable" for Illinois lakes.

    IEPA sampled 72 of the 145 lakes during the summer of  1977.   It is not
appropriate to gauge the accuracy of the  1973  parameter estimates in terms of
the 1977 field measurements.  The 1973 data were collected in the middle of
October.  By contrast, the 1977  data were collected during the summer when
the Secchi depth would be expected to be  lower because of  plankton biomass
and recreational uses that suspend and resuspend particulate matter and
intense agricultural activities  that contribute substantially to  the
 particulate load.  Recognizing the limitations imposed by the dynamic nature
of inland water bodies, a comparison was made  for the 72  lakes using Secchi
depth, a parameter common to both data sets.   The mean Secchi depth values  (N
=  72)  for 1973 and 1977 are  0.98 and 0.97 m, respectively.   The
product-moment correlation coefficient, significant at the 0.01  level,  is
0.505.  However, because the data were collected or estimated for different
                                     128

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      TABLE 16.  TROPHIC INDICATOR AND MULTIVARIATE TROPHIC INDEX OBSERVED, ESTIMATED, AND RESIDUAL VALUES
                 FOR THE SET THREE REGRESSION MODELS
ro

Name
Carlyle
Cedar
Charleston
Crab Orchard
Decatur
DePue
East Loon
Fox
Grass
Holiday
Long
Marie
Old Ben Mine
Pi stakee
Raccoon
Rend
Shelbyville
Si ocum
Storey
Vandal ia
We-Ma-Tuk
Wonder
Serial
Number
14
55
16
127
73
3
53
60
61
51
52
62
32
65
80
29
114
54
50
27
33
69
SEC
0.48
2.77
0.25
0.36
0.46
0.15
0.91
0.36
0.31
0.46
0.31
0.56
0.48
0.31
0.41
0.61
0.48
0.31
0.89
0.71
1.07
0.46
SEC
0.42
1.19
0.27
0.62
0.29
0.25
0.85
0.35
0.31
0.43
0.44
0.36
0.57
0.54
0.31
0.58
0.67
0.34
0.93
0.89
0.62
0.31
SEC-SEC
0.06
1.58
-0.02
-0.26
0.17
-0.10
0.06
0.01
0.00
0.03
-0.13
0.20
-0.09
-0.23
0.10
0.03
-0.19
-0.03
-0.04
-0.18
0.45
0.15
CHLA
19.9
5.6
18.0
46.7
21.4
42.4
26.8
37.4
46.1
67.0
61.2
70.7
24.6
66.5
10.6
15.6
12.8
241.4
30.0
13.5
8.3
198.0
CHLA
10.3
26.7
36.0
26.5
48.6
45.4
25.8
46.5
46.8
37.6
43.6
59.9
18.4
33.5
19.6
18.0
15.4
229.4
30.4
19.4
5.0
157.5
CHLA-CHLA
9.6
-21.1
-18.0
20.2
-27.2
- 3.0
1.0
- 9.1
- 0.7
29.4
17.6
10.8
6.2
33.0
- 9.0
- 2.4
- 2.6
12.0
- 0.4
- 5.9
3.3
40.5
TON
0.742
1.105
1.200
0.843
0.590
2.020
1.380
0.970
1.773
1.200
2.074
1.896
1.690
1.635
0.900
0.971
0.595
5.940
0.980
1.019
0.588
1.788
TON
0.598
1.160
1.308
1.010
1.410
1.492
1.225
1.252
1.391
1.477
1.326
1.612
1.307
1.142
0.856
0.854
0.828
5.118
0.898
0.853
0.820
2.068
TON-fON
0.144
-0.055
-0.108
-0.167
-0.820
0.528
0.155
-0.282
0.382
-0.277
0.754
0.284
0.383
0.493
0.044
0.117
-0.233
0.822
0.082
0.166
-0.232
-0.280
                                                                                                  (continued)

-------
                                               TABLE 16.  (continued)
co
o

Name
Carlyle
Cedar
Charleston
Crab Orchard
Decatur
DePue
East Loon
Fox
Grass
Hoi id ay
Long
Marie
Old Ben Mine
Pistakee
Raccoon
Rend
Shelbyville
Sloe urn
Storey
Vandal i a
We-Ma-Tuk
Wonder
Serial
Number
14
55
16
127
73
3
53
60
61
51
52
62
32
65
80
29
114
54
50
27
33
69
TPHOS TPHOS TPHOS-fPHOS PC1Y5
0.091
0.053
0.207
0.114
0.143
0.499
0.087
0.212
0.347
0.173
0.785
0.286
0.930
0.216
0.145
0.065
0.063
1.330
0.125
0.175
0.103
0.423
0.056
0.135
0.349
0.138
0.272
0.413
0.176
0.200
0.226
0.238
0.187
0.326
0.328
0.156
0.155
0.083
0.083
1.425
0.174
0.122
0.171
0.468
0.035
-0.082
-0.142
-0.024
-0.129
0.086
-0.089
0.012
0.121
-0.065
0.598
-0.040
0.602
0.060
-0.010
-0.018
-0.020
-0.095
-0.049
0.053
-0.068
-0.045
-0.90
-2.89
0.02
0.14
-0.17
2.41
-0.77
1.68
1.84
1.22
1.98
0.33
1.55
1.63
-0.48
-1.13
-1.62
4.31
-1.07
-1.32
-1.35
2.29
PC1Y5 PC1Y5-PC1YE
-1.22
-0.36
1.03
-0.14
1.10
1.36
-0.17
0.88
0.75
0.63
0.46
1.47
0.11
0.12
-0.03
-0.96
-1.20
4.92
-0.69
-1.02
-1.15
1.96
-0.32
2.53
1.01
-0.28
1.27
-1.05
0.60
-0.80
-1.09
-0.59
-1.52
1.14
-1.44
-1.51
0.45
0.17
0.42
0.61
0.38
0.30
0.20
-0.33
> PC1F5
-0.78
-2.67
0.78
-0.22
-0.51
2.61
-0.55
0.67
1.71
0.86
2.59
1.43
2.38
1.52
-1.01
-1.19
-1.35
4.56
-0.47
-1.13
-1.33
2.33
£C1F$ PC1F5-PC1F5
-1.58
-0.26
1.27
-0.19
1.11
1.64
0.06
0.71
0.77
0.78
0.46
1.51
0.74
0.08
-0.11
-1.03
-1.18
5.15
-0.34
-0.80
-0.63
2.18
-0.80
2.41
0.49
0.03
1.62
-0.97
0.61
0.04
-0.94
-0.08
-2.13
0.08
-1.64
-1.44
0.90
0.16
0.17
0.59
0.13
0.33
0.70
-0.15

-------
TABLE 17.  COMPARISON OF THE RANGE OF NES SAMPLE VALUES WITH THE 95 PERCENT CONFIDENCE LIMITS OF
           PREDICTED VALUES
                 SEC
             OBS*    PRED**
     CHLA
OBS*      PRED**
      TPHOS
OBS*         PRED**
     TON
OBS*
PRED**
Carlyle
Cedar
Charleston
Crab
Orchard
Decatur
DePue
E. Loon
Fox
Grass
Hoi id ay
Long
Marie
Old Ben
Mine
Pistakee
Racoon
Rend
Shelby-
ville
Sloe urn
Storey
Vandal i a
We-Ma-Tuk
Wonder
0.4-0.6
2.8
0.3

0.3-04
0.5
0.2
0.9
0.3-0.4
0.3
0.3-0.6
0.3
0.3-0.8

0.5
0.3
0.4-0.5
0.5-0.8

0.3-0.9
0.3
0.8-0.9
0.6-0.9
0.9-1.2
0.3-0.6
0.2-1.3
0.4-4.8
0.1-0.7

0.3-1.9
0.1-0.7
0.1-0.6
0.3-3.0
0.2-0.9
0.1-0.8
0.2-1.2
0.2-1.2
0.2-0.9

0.2-1.9
0.2-1.6
0.1-0.8
0.3-1.7

0.3-2.0
0.1-1.2
0.3-3.5
0.3-3.0
0.2-2.0
0.1-0.8
9.8-38.8
5.6
11.2-24.9

29.4-77.6
6.3-33.9
42.4
26.8
24.3-80.6
37.7-54.6
66.5-67.5
60.7-61.8
59.6-81.9

24.6
59.7-73.3
3.1-18.1
10.3-21.7

5.3-26.3
241.4
16.2-43.8
10.1-18.0
5.2-11.4
188.0-211.0
1.1-47.7
5.6-88.1
8.6-109.3

5.9-81.8
13.5-135.7
11.4-129.0
5.3-83.5
12.2-133.7
12.9-132.2
9.1-113.2
11.4-125.8
17.4-161.0

2.9-70.5
8.2-100.4
3.4-69.7
3.3-62.2

2.7-55.5
73.7-571.0
5.5-108.2
3.6-67.5
0.4-28.2
47.0-416.9
0.076-0.
0.029-0.
0.172-0.

0.071-0.
0.111-0.
0.499
0.085-0.
	
0.283-0.
0.152-0.
0.744-0.
0.262-0.

0.920-0.
0.201-0.
0.073-0.
0.047-0.

0.023-0.
1.330
0.053-0.
0.044-1.
0.066-0.
0.363-0.
119
093
229

257
173

089

438
212
828
318

940
232
299
082

128

321
020
177
477
0.004-0.
0.020-0.
0.080-1.

0.023-0.
0.061-0.
0.098-1.
0.031-0.
0.037-0.
0.047-0.
0.048-0.
0.035-0.
0.076-1.

0.065-1.
0.027-0.
0.023-0.
0.010-0.

0.010-0.
0.394-3.
0.030-0.
0.019-0.
0.025-0.
0.119-1.
318
534
093

507
868
234
638
703
758
799
659
000

115
565
604
357

355
947
638
476
681
270
0.88-1.24
0.98-1.31
0.69-1.50

0.56-1.83
0.36-0.94
2.02
1.25-1.84
	
1.27-2.29
0.97-1.36
1.76-2.24
1.61-2.18

1.54-1.84
1.54-1.73
0.74-1.06
0.76-143

0.39-1.02
5.94
0.86-1.48
0.75-1.89
0.45-0.51
0.97-2.25
0.
0.
0.

0.
0.
0.
0.
0.
0.
0.
0.
0.

0.
0.
0.
0.

0.
1.
0.
0.
0.
0.
32-1.30
58-2.72
65-3.11

53-2.16
71-3.31
72-3.58
61-2.85
63-2.93
70-3.26
72-3.58
66-3.11
79-3.93

62-3.31
59-2.57
45-1.89
46-1.81

45-1.74
70-21.27
47-2.23
46-1.81
43-1.86
95-5.38

 *OBS = Observed sample range
**PRED = 95% limits for predicted value  (point estimate)

-------
TABLE 18.  SUMMARY STATISTICS FOR SET THREE (SPECTRAL RANK) REGRESSION
           MODELS
Parameter
GRNRK
GRNRK
REDRK
REDRK
IR1RK
IR1RK
IR2RK
IR2RK
RAT100
RAT100
SEC
SEt
residuals
SEC
CHLA
CHLA
residuals
CHLA
TON
TON
residuals
fOff
TPHOS
TPHOS
resjduals
TPHOS
PC1F5
P~C1F5
residuals
PC1F5
PC1Y5
"PC1Y5"
residuals
PcTv?
N
22
145
22
145
22
145
22
145
22
145
22
22
22
145
22
22
22
145
22
22
22
145
22
22
22
145
22
22
22
145
22
22
22
145
Mean
64.68
73.00
69.82
73.00
55.45
73.00
40.86
73.00
5.75
2.71
0.60
0.52
-0.07
0.76
49.30
45.31
-3.98
30.60
1.44
1.36
-0.09
1.27
0.30
0.27
-0.03
0.30
0.46
0.47
0.00
0.48
0.35
0.35
0.00
0.13*
Median
64.00
73.00
63.50
73.00
52.00
73.00
31.00
73.00
2.29
1.42
0.46
0.44
-0.01
0.48
2"8.40
31.94
-0.50
24.67
1.15
1.23
-0.10
1.16
0.17
0.18
0.02
0.26
0.23
0.30
0.22
0.60
0.08
0.11
-0.17
0.20
Maximum
136.00
145.00
123.00
145.00
135.00
145.00
104.00
145.00
48.50
81.67
2.77
1.17
0.27
7.41
241.4
227.8
27.6
229.4
5.94
5.08
0.82
5.12
1.33
1.42
0.14
1.62
4.56
5.13
2.13
5.15
4.31
4.89
1.52
4.92
Minimum
8.00
1.00
11.00
1.00
6.00
1.00
4.00
1.00
-11.94
-71.75
0.15
0.25
-1.60
0.17
5.60
5.00
-40.48
0.91
0.59
0.59
-0.86
0.41
0.05
0.05
-0.60
0.02
-2.67
-1.60
-2.41
-3.61
-2.89
-1.24
-2.53
-3.70
Standard
Deviation
33.46
42.00
28.30
42.00
32.59
42.00
29.31
42.00
13.90
18.24
0.54
0.25
0.38
0.79
59.11
50.86
17.13
29.92
1.11
0.89
0.39
0.65
0.33
0.28
0.20
0.25
1.77
1.42
1.04
1.38
1.72
1.38
1.03
1.32
Skew
0.41
0.00
0.26
0.00
0.54
0.00
0.83
0.00
2.08
1.11
3.22
1.02
-3.16
4.67
2.35
2.69
-0.33
3.29
3.13
3.43
0.04
3.56
1.96
3.38
-2.27
2.90
0.41
1.48
-0.02
0.30
0.30
1.53
-0.37
0.22
Kurtosis
2.65
1.80
2.88
1.80
2.82
1.80
2.70
1.80
6.70
9.73
13.58
3.20
13.45
35.28
7.63
9.50
2.73
18.58
13.43
14.94
3.03
19.85
6.10
14.60
7.19
12.16
2.52
6.25
3.24
1.37
2.56
6.27
2.94
1.40
                                   132

-------
seasons it would be inappropriate to suggest  that, overall, Secchi
transparency has changed or,  for that matter,  remained the same.

    Trophic indicator rankings for the 145  lakes are found in Table 19.  A
composite rank value was determined for each  lake by pooling its four trophic
indicator rank values and then once again ranking the 145 lakes (Table 20).
In general, the rank positions are in good  agreement with the 1977
qualitative and quantitative information.   As always, however, these
comparisons can only serve as a rough guide,  since  in making them it is
assumed that the lakes have been stable from  1973,  rather than dynamic,
changing, and nonuniform, as is actually observed.

CLUSTER ANALYSIS

    Cluster analysis ("numerical classification"  in the  words of Boesch  1977)
was used to order the 145 Illinois water bodies into groups.  Separate
clusterings were accomplished using just the  LANDSAT bands as attributes  in
sets of three (6RN, RED, IR1) and four (GRN,  RED,  IR1,  IR2).  Additional
clusterings were made using, as attributes, the LANDSAT-estimated values  for
four trophic  indicators  (CHLA, SEC, TON, and  TPHOS).

Spectral Classification  of the Lakes

    In this subsection,  the results of the cluster analysis  of  raw  MSS  data
are discussed.  Natural  lake groupings were established  according to  spectral
characteristics from the four attributes (i.e., GRN, RED,  IR1,  and  IR2  bands)
for 145  Illinois water bodies.  The objective of the classification process
was to demonstrate  general lake characteristics associated with  user
impairment.   Interpretation of the  dendrogram (Figure 58)  established  six
distinct  water  groups of dissimilar spectral  composition and intensity.   The
groups  are comprised  of  water bodies  having similar optical  and physical
characteristics.   The clustering  algorithm provides a nonbiased perspective
of the  spectral traits  of the lakes.   The  spectral properties of each lake
provide  an integrated characterization of  water quality and relate  to
water-use indices.

    Cluster interpretation  was  accomplished by comparing the spectral
composition and uniqueness  of each  cluster with water quality data, field
evaluations,  lake  morphology, and watershed  characteristics.  The LANDbAT
 flyover during  October  of  1973  was  supported  by chemical, physical, and
biological data collected by the NES sample  program for 31 lakes.  Since the
 classification procedure utilized spectral responses, the NES data were of
 limited value because many  of the NES lake parameters have little or no
 direct impact on the lake  spectra.   Field  surveys were made during the summer
 of 1977 for 72 of the MSS-sampled lakes.   These surveys included physical,
 biological, and chemical information useful  for comparison of lake clusters.
 Lake  morphology, watershed  information,  and  field  evaluations of user
 impairments were available  for most lakes  to supplement the ground
 information base.
                                      133

-------
TABLE 19.  RANKINGS OF 145 ILLINOIS LAKES BASED ON SET THREE MODELS
           AND ORDERED BY NAME

Serial
Lake Name Number
Anderson
Apple Canyon
Argyle
Bakers
Bangs
Bath
Big
Big
Bracken
Calumet
Canton
Carbondale
Carlyle
Catherine
Cattail
Cedar
Cedar
Central i a
Chain
Channel
Charleston
Chautauqua
Clear
Coal City
Recreation Club
Commonwealth Edison-
Dresden Nuclear
Countryside
Crab Orchard
Crane
Crooked
Crystal
Decatur
Deep
DePue
Devil's Kitchen
Di amond
DuQuoin
Dutchman
East Loon
Fourth Lake
34
144
157
19
56
166
134
176
145
18
36
38
14
58
125
39
55
79
83
59
16
87
86
138

137

148
127
85
149
68
73
150
3
128
57
98
49
53
151
SEC
127
29
40
110
32
108
70
117
21
142
73
134
79
25
86
76
30
31
116
50
121
140
124
10

92

51
57
137
65
23
111
9
130
6
37
67
11
47
115
CHLA
112
38
3
99
66
11
50
68
19
96
22
131
30
102
69
14
85
27
93
101
103
105
109
18

52

119
83
81
125
51
124
63
120
36
39
136
20
79
115
TON
86
45
5
104
35
70
32
57
36
88
10
82
4
80
127
29
73
52
90
81
94
95
102
3

14

91
49
78
115
19
105
30
118
47
13
140
39
85
89
TPHOS
84
39
22
132
16
109
55
74
50
119
25
127
3
36
134
63
34
54
107
44
95
111
117
11

15

67
35
108
125
13
75
7
118
33
5
124
52
48
80
PC1Y5
120
35
5
127
38
85
47
87
27
125
25
100
19
61
109
30
51
28
110
72
112
121
123
3

41

90
59
104
136
18
114
33
126
16
14
130
23
56
116
PC1F5
107
39
7
130
26
96
50
74
37
122
21
111
8
52
127
41
44
40
110
58
108
119
121
3

25

75
49
106
132
15
101
18
125
27
11
131
36
53
102
                                                              (continued)
                                 134

-------
TABLE 19.  (continued)

Lake Name
Fox
Fyre
Gages
George
Glen 0. Jones
Goose
Goose (Village)
Grass
Greenville New City
Griswold
Harrisburg
Highland
Holiday
Horseshoe
Jack, Swan, Grass
Keithsburg
Kinkaid
Kinneman
Lake of Egypt
Lake of the Woods
Larue-Pine
Lily
Lincoln Trail
Little Grassy
Little Swan
Liverpool
Long
Long
Lower Smith
Lyerla-Autumnal
Marie
Marion
Marshall
Matanzas
Mattoon
McCul 1 om
McGinnis
Meredosia
Mesa
Moscow
Moses
Mound
Serial
Number
60
170
152
108
110
101
139
61
2
158
111
153
51
1
165
92
40
168
132
115
121
136
13
119
185
88
52
177
181
120
62
129
81
89
24
159
20
10
184
164
28
163
SEC
94
53
28
18
2
145
99
106
80
66
55
35
78
85
123
75
1
101
19
109
107
135
3
5
89
119
77
131
88
59
91
48
114
138
62
22
133
141
16
87
20
90
CHLA
121
87
84
6
21
135
7
122
123
70
67
116
107
92
127
58
2
26
16
37
141
49
28
43
40.5
8
118
73
113
34
134
106
140
91
31
24
142
88
13
71
57
138
TON
87
120
54
12
16
133
37
103
101
117
99
100
114
132
121
112
1
44
6
113
143
72
42
38
21.5
60
96
69
15
76
126
134
108
84
11
28
144
83
20
62
111
122
TPHOS
59
93
24
18
14
138
87
65
76
100
78
43
69
135
112
130
1
104
4
131
145
123
32
20
56.5
113
53
105
58
110
89
126
121
91
19
28
144
115
17
82
86
101
PC1Y5
106
93
48
11
10
140
49
101
98
84
64
79
97
122
131
96
2
65
6
118
143
92
12
21
42.5
80
89
94
26
76
128
105
113
108
24
17
144
115
15
82
54
117
PC1F5
79
98
34
12
9
139
66
82
89
97
69
60
83
133
126
116
1
78
5
128
143
104
23
20
45.5
91
67
100
38
90
118
120
117
103
17
24
144
114
16
80
71
115
                                       (continued)
          135

-------
TABLE 19.  (continued)

Lake Name
Murphysboro
New Pittsfield
Nippers ink
Old Ben Mine
Olney East Fork
Olney New
Open Pond
Otter
Pana
Paradise
Paris Twin
Pekin
Petite
Pierce
Pinckneyville
Pistakee
Powerton Cooling
Quiver
Raccoon
Rend
Rice
Round
Saganashkee
Sahara Coal Company
Sam Dale
Sam Parr
Sand
Sanganois
Sara
Sawmi 1 1
Senachwine
Shelbyville
Skokie Lagoons
SI ocum
Snyder's Hunting
South Wilmington
Spring
Spring
Spring
Spring
Spring Arbor
St Mary's
Serial
Number
37
100
63
32
106
107
174
167
113
15
25
116
64
130
99
65
182
90
80
29
35
66
21
175
124
41
147
9
26
103
104
114
22
54
142
140
4
8
67
118
143
146
SEC
14
129
102
64
13
39
74
60
49
83
42
126
84
52
72
68
71
100
104
63
103
33
96
118
43
41
15
122
4
144
143
56
95
98
69
7
120
139
93
82
27
17
CHLA
25
45
126
56
29
32
60
23
4
76
55
44
117
90
97
95
104
54
62
53
133
65
139
1
94
64
82
77
15
143
137
46
98
145
59
9
108
111
40.5
129
48
12
TON
43
31
106
93
9
74
119
53
8
59
109
61
97
66
79
71
68
41
25
24
125
34
135
48
110
128
51
56
26
142
124
18
137
145
123
2
136
98
21.5
116
107
27
TPHOS
41
66
70
90
6
81
133
79
31
61
92
98
71
51
62
42
45
64
40
12
97
10
122
114
68
129
23
102
29
142
103
9
141
143
116
2
139
96
56.5
85
99
60
PC1Y5
13
62
111
69
8
46
103
44
7
71
57
78
102
60
91
70
86
55
63
32
132
36
134
68
81
83
45
77
9
142
138
20
135
145
67
1
133
119
42.5
124
53
34
PC1F5
30
59
94
81
6
61
123
57
10
64
76
85
88
56
68
54
63
55
51
19
124
22
134
84
72
109
33
86
13
142
129
14
140
145
95
2
137
112
45.5
113
77
42
                                       (continued)
         136

-------
                          TABLE 19.  (continued)
Lake Name
Stephen A. Forbes
Storey
Sugar Creek
Summerset
Sunfish
Swan
Swan
Tampier
Third
Thunderbird
Turner
Upper Smith
Vandal i a
We-Ma-Tuk
West Frankfort New
West Frankfort Old
West Loon
Wolf
Wonder
Worl ey
Yorkey
Zurick
Serial
Number
78
50
178
186
126
93
172
23
155
173
102
180
27
33
31
30
156
17
69
117
179
154
SEC
26
44
125
46
81
112
132
61
54
8
136
97
45
58
34
38
12
36
105
113
128
24
CHLA
47
89
114
74
33
17
132
35
128
5
130
72
61
10
78
110
80
42
144
86
75
100
TON
50
33
55
92
65
63
138
64
130
7
141
58
23
17
75
131
46
40
139
129
67
77
TPHOS
37
47
106
49
83
120
137
77
73
8
140
72
27
46
38
94
21
26
128
136
88
30
PC1Y5
37
40
74
73
66
75
139
52
107
4
141
88
31
22
50
99
39
29
137
129
95
58
PC1F5
35
43
87
62
70
93
138
65
99
4
141
73
28
32
47
105
31
29
136
135
92
48
    Cursory examination of the remote-sensing data indicated that the  natural
groupings of lakes developed by cluster analysis techniques discriminated
groups of water bodies, each with its own unique physical  qualities.   Data  for
the four LANDSAT bands were rescaled in a manner suggested by Ruttner  (1963).
Thus, the raw reflectance values were transformed into percentages that were
used as a four-element index of lake wavelength reflectance characteristics.
The maximum and minimum reflectance values recorded for each band were assumed
to represent a reasonable range to form the base index signatures.
Establishing the range from actual energy return signals for water bodies
minimized the path radiance interference from the base signal.  Ground control
data for suspensoids and Secchi depths verified this assumption.

    This characterization of lake waters by their optical  spectrum relies upon
the relationships between the energy reflectance of the clearest Illinois lake
and waters containing greater concentrations of suspended or dissolved matter.
The procedure is similar to that used by Rogers (1977) except that no  lake in
the Illinois MSS program is considered an exceptionally pure-water lake.
Hence, Illinois lake index signatures of reflectance data represent actual
                                        137

-------
   TABLE 20.   COMPOSITE RANKING OF 145 ILLINOIS WATER BODIES BASED ON SET
              THREE MODELS AND ORDERED BY INCREASING TROPHIC STATE
Lake Name
Serial
Number  RANKSUM
Kinkaid
South Wilmington
Thunderbird
Coal City Recrea-
tion Club
Lake of Egypt
Glen 0. Jones
George
Olney East Fork
Mesa
Argyl e
Sara
Pana
Diamond
McCullom
Lincoln Trail
Crystal
Little Grassy
Deep
Carlyle
St Mary's
Dutchman
Devil's Kitchen
Mattoon
Murphysboro
Bracken
Shelbyville
Canton
We-Ma-Tuk
Round
Wolf
Bangs
Apple Canyon
Rend
Vandal i a
West Loon
Stephen A. Forbes
Central i a
Sand
Commonwealth Edison-
Dresden Nuclear
40
140
173
138

132
110
108
106
184
157
26
113
57
159
13
68
119
150
14
146
49
128
24
37
145
114
36
33
66
17
56
144
29
27
156
78
79
147
137

1
2
3
4

5
6
7
8
9
10
11
12
13
14
15
17
17
18
20
20
22
22
24
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

Serial
Lake Name Number RANKSUM
Cedar
Gages
Big
Little Swan
Spring
Storey
Otter
Cedar
Crab Orchard
West Frankfort New
Olney New
Goose (Village)
Raccoon
Zurick
Tampier
Catherine
East Loon
Quiver
Pierce
Summerset
Sunfish
New Pittsfield
Moses
Lower Smith
Ki nneman
Channel
Pi stakee
Paradi se
Lye rl a- Autumnal
Spring Arbor
Sahara Coal Company
Powerton Cooling
Highland
Paris Twin
Bath
Harri sburg
Upper Smith
Liverpool
Moscow
Old Ben Mine
39
152
134
185
67
50
167
55
127
31
107
139
80
154
23
58
53
90
130
186
126
100
28
181
168
59
65
15
120
143
75
182
153
25
166
111
180
88
164
32
40
41
42
43
44
45
46
47
48
49
50
51
53
53
54
55
57
57
57
59
60
61
63
63
64
66
66
68
68
70
70
71
72
74
74
76
76
77
78
79
                                                                    (continued)
                                      138

-------
                             TABLE  20.   (continued)
Lake Name
Serial
Number  RANKS LM
Lake Name
Serial
Number  RANKSUM
Pinckneyvil le
Swan
Sam Dale
Big
Countryside
Pekin
Long
Griswold
Fyre
Sanganois
Yorkey
Fox
Sam Parr
Snyder's Hunting
Hoi iday
Petite
West Frankfort
Old
Keithsburg
Long
Lily
Greenville New
City
Third
Open Pond
Lake of the Woods
Grass
Fourth Lake
Sugar Creek
Nippers ink
Crane
Matanzas
Chain
Anderson
99
93
124
176
148
116
52
158
170
9
179
60
41
142
51
64
30

92
177
136
2

155
174
115
61
151
178
63
85
89
83
34
80
81
82
83
84
85
86
88
88
89
90
91
92
93
94
95
96

97
98
99
100

101
102
103
104
105
106
108
108
108
110
111
Spring
Charleston
Marion
Decatur
Cattail
Me red os i a
Crooked
Marie
Horseshoe
Spring
Cal umet
Bakers
Chautauqua
Mound
Clear
Rice
Worl ey
DuQuoin
Skokie Lagoons
Carbondale
Marshall
Jack, Swan, Grass
DePue
Saganashkee
Spring
Senachwine
Wonder
Sloe urn
La rue-Pine
Swan
Turner
Goose
McGinnis
Sawmill
118
16
129
73
125
10
149
62
1
8
18
19
87
163
86
35
117
98
22
38
81
165
3
21
4
104
69
54
121
172
102
101
20
103
112
113
114
115
116
117
118
119
121
121
123
123
125
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
                                      139

-------
                               i * *is
                               $«iji
                               o ! It*

                                 ^
              -u-
                                Serial Number and Lake Name
                                       Cluster Number
Figure 58.   Dendrogram  of  145 Illinois water bodies based on complete linkage clustering on four
            spectral attributes  (GRN, RED, IR1, IR2).  The dissimilarity  axis is in the distance
            scale A.  The  attributes' values were not standardized  prior  to  computing the A?
            values for  the resemblance matrix.

-------
optical qualities for these lakes and are not a comparison of  these  lakes  to
"pure-water lakes" found elsewhere.

    Generalized signatures for various types of Illinois  water bodies  are
found in Table 21.  These signatures represent actual  reflectance  differences
in the LANDSAT MSS bands for lake waters integrated over  Secchi  depth.   Since
most Illinois lakes exhibit a Secchi depth of less than one meter, and  because
most solar radiation is absorbed within one meter (Ruttner 1963),  the
procedure provides a reasonable demonstration of Illinois lake properties.
Use of the actual range of recorded spectral values to establish index
signatures provides an objective and comparable data base to establish  a "real
world" interpretation of Illinois lake groups.

    Cluster analysis resulted in'the delineation of 6 groups of 21 to  28 lakes
each, arranged in distinct subgroups (Figures 58 and 59).  Index signatures
and general lake qualities for the six clusters are in shown Table 22.

    Some semi quantitative characteristics of the lake clusters and their
subclusters at level six are readily apparent when compared to the ground
control data in Table 23.  The six clusters can be ordered on  the  basis of
declining water quality as follows:  3-1-2-5-4-6.  Based  upon  this order,
Figure 60 demonstrates the correlation between spectral signatures and 1977
Secchi depth and suspensoid levels for 72 of the 145 lakes. Suspensoid
contact-sensed data are available for 1977 for each subcluster of  clusters 1
to 6 and represent 42 to 82 percent of the lakes in each  group. The obvious
relationship between Secchi depth and proportionate concentrations of  volatile
(organic) and total suspended solids suggest that the lake clusters  can be
discriminated by Secchi depths, total suspended matter, and the proportions  of
inorganic-organic suspensions.

    Clusters 3 and 1 have similar organic suspensoid levels but are  separable
by their inorganic suspensoid levels and associated changes in Secchi  depths.
Clusters 5 and 4 demonstrate a similar pattern indicating that inorganic
turbidities account for the differences between Clusters  3 and 1 and also for
those between 5 and 4.  Cluster 2 represents lakes exhibiting  qualities
between these two sets.  Algal concentrations for the 72  lakes sampled during
1977 closely follow the volatile suspended solids values  indicating  that
primary productivity increases from Cluster 3 to 5 and then decreases  in
Cluster 4.  The abrupt reduction in algal counts from Cluster  5 to 4
corresponds with a 100 percent increase in inorganic suspensions and a Secchi
depth reduction of 50 percent (to 0.28 m) in Cluster 4.  Cluster 6 appears to
follow the ordered relationship according to actual spectral information;
contact-sensed data to demonstrate suspensoid levels and Secchi depth
relationships for this cluster are available for only four lakes.   Generally,
lakes in Cluster 6 are considered poor quality lakes that were either
privately owned lakes or were too shallow to sample during the 1977  survey.

    Figure 61 suggests that the 1973 NES data and the  1977 IEPA data for
Secchi depth qualitatively corresponds with the LANOSAT  RED band.   Figure 62
demonstrates the correspondence of suspensoid levels and light extinction
properties of Illinois lakes during  1977.  The relationship between
suspensoids, Secchi depth, and spectral response  is obvious.  Generally, the

                                      141

-------
 TABLE 21.  INDEX SIGNATURES FOR VARIOUS WATER BODY TYPES  IN ILLINOIS
Type of Water Body
                       LANDSAT MSS Band Percentages
                       GRN       RED   IR1       IR2
Clean glacial lakes
Clear deep reservoirs
Low algal clear reservoirs
High algal reservoirs
High algal glacial lakes
Turbid reservoirs
River backwaters
Sloughs and harbors
5
5
20
30
25
40
55
85
10
5
20
30
25
45
55
90
5
15
15
25
20
30
50
90
5
25
10
10
5
25
30
90

TABLE 22.   INDEX SIGNATURES AND GENERAL DESCRIPTIONS FOR SIX ILLINOIS LAKE
            CLUSTERS
 Cluster
 Number
   Signature
GRN-RED-IR1-IR2
         Cluster Description
   3


   1
  10-10-15-16


  25-22-22-19



  27-29-33-23
              40-42-54-41
              49-53-41-21
              67-68-62-44
Deep clear lakes of excellent quality with
macrophytes

Deep somewhat clear lakes of good to very
good quality with slight sediment, algal,
and macrophyte problems

Moderate depth lakes of good quality with
moderate silt and algal problems, slight
macrophyte problems, and average Secchi
depths

Shallow reservoirs and backwaters of fair
quality with moderate sediment problems and
severe algal problems

Shallow lakes and backwaters of poor quality
with low Secchi depths and severe sediment-
related problems

Shallow lakes and backwaters of very poor
quality with sediment-related
turbidity problems
                                     142

-------
 X
 LU
 Q
     801
     70-
    60H
     50-
 LU
 O
 z
 <
 5  40-
 LU
     30-
     20-
     10-
         f-MSSGRN-Hf MSSRED-*- MSS IR1
I
MSS IR2
           550      650     750              950

                    WAVELENGTH (Nanometers)
Figure 59.  Spectral index signature curves for six lake clusters
           based upon raw MSS data.
                            143

-------
TABLE 23.  SPECTRAL DATA AND CONTACT-SENSED DATA FOR THE CLUSTERS AND SUBCLUSTERS DEVELOPED USINli
           COMPLETE LINKAGE CLUSTERING ON FOUR ATTRIBUTES (GRN, RED, IR1, IR2)*


3d
b
a
c
3
Ib
c
a
d
1
2d
a
c
b
2
5a
b
e
c
d
5
Clusl
Nunb«
and
rer
•r

(Obs.) GRN
(10
( 3
( 8
( 7
{28
( 6
( 9
( 8
( 1
11
6
13
5
10
29
21
22
50
(24) 25
( 3
( 7
5
(6
11
29
29
30
(21) 27
( 5) 42
( 3) 34
( 3) 31
( 8
( 4
(23
44
38
40
Scaled Spectral
Signature

RED
9
2
13
11
10
23
22
19
19
22
17
32
26
34
29
46
38
27
47
41
42

IR1
6
13
18
25
15
24
17
27
17
22
35
26
37
35
33
41
46
72
55
58
54

IR2
5
33
17
30
16
21
10
29
15
19
46
10
34
19
23
36
37
52
32
61
41
IEPA Data
(1977)

TSS
6.4
1.3
8.8
8.7
7.0
6.6
10.3
9.3
1.0
9.7
3.0
14.5
15.3
39.3
21.8
13.7
27.0
25.0
31.0
65.0
31.7

VSS
5.4
1.0
6.4
6.9
5.9
4.4
9.0
3.7
0.0
5.8
2.0
9.0
10.6
18.3
11.9
8.7
16.0
21.0
16.0
40.0
21.5

SEC
1.32
3.31
1.14
0.95
1.43
1.40
1.13
1.04
1.97
1.27
1.65
1.51
0.70
0.39
0.88
1.37
0.33
0.34
0.30
0.14
0.59
Observed
Problems
4J
I .
5 s,
5
1.3
1.0
1.6
2.0
1.5
2.0
2.0
1.9
1.0
1.9
2.0
2.6
2.5
2.6
2.5
2.2
2.3
2.3
3.3
3.3
2.7
<
2.0
1.3
2.4
2.6
2.2
2.0
2.4
1.9
1.0
2.1
2.5
2.7
2.5
2.4
2.6
2.2
2.5
3.7
2.0
3.0
2.5
01
*
?
^f

2.7
1.7
2.7
2.7
2.6
2.4
1.8
2.7
2.0
2.3
3.0
1.9
3.0
1.8
2.3
1.8
2.3
3.0
1.7
2.0
2.0
NES Data
(1973)

SEC
2.77

0.91

1.83
0.70
0.43


0.49

0.40
0.49
0.46
0.43

0.18
0.31


0.24

CIILA
6

27

17
13
39


33

54
24
198
77

182
241


212
Morphology
I
3.72
7.53
3.84
3.57
4.12
4.57
3.63
4.63
8.75
4.42
2.65
2.23
2.80
2.23
2.44
4.60
1.07
0.76
1.49
0.61
1.83
*m
11.19
21.23
9.85
8.90
11.46
11.95
10.33
11.16
24.38
11.58
8.23
6.22
5.73
5.06
6.10
8.96
2.59
1.95
3.60
1.74
4.30
tershed
ulvalent
ntlmeters
533
90.9
61.2
39.4
22.1
53.B
33.0
43.4
25.9
56.9
34.8
31.2
18.8
23.4
19.8
23.1
13.5
16.0
6.9
30.0

13.2
Hydrology
c
o
iff f~
Vt O 4J
1 °^
4-» Of » 91
c § ** e
o» v 5 * •"
•ME f— r— t3
SI
4.20
1.81
1.46
0.71
2.25
1.30
2.09
1.00
1.72
1.46
0.97
0.57
0.94
0.95
0.90
0.54
0.78
0.34
1.07

0.69
££$
0.13
0.09
0.40
0.30
0.32
0.18
0.11
0.20
0.04
0.16
0.24
0.14
0.07
0.13
0.14
1.17
0.28
0.59
0.12

0.72
.c
 QC 0
I-* C
> 3
i-H J3 CC
9.7
6.2
9.2
32.0
18.9
9.0
57.6
11.7
6.7
29.7
13.6
23.7
13.6
23.0
25.4
272.0
40.0
61.5
19.2

143.2
Biota
-i
as
n
9 C
*— 1 UJ
0.6
0.4
2.8
5.2
2.3
1.2
1.4
6.9
0.3
2.5
13.0
5.3
3.2
9.5
7.7
4.9
11.3
30.5
2.9
7.4
11.4
                                                                                          (continued)

-------
                                                                TABLE  23.    (continued)
en
Cluster
Number
and
(Obs.
4c ( 5
d ( 6
a ( 8

) CRN
56
44
51
b ( 5) 46
4 (24) 49
6a (12) 59
b ( 4) 70
c ( 6
d ( 3
71
91
6 (25) 67
Scaled Spectral
Signature

RED
56
47
56
51
53
62
77
56
88
68

1R1
43
34
48
49
41
57
68
54
80
62

1R2
18
11
27
24
21
33
39
62
69
44
1EPA Data
(1977)

TSS
57.3
29.0
77.8
120.0
61.8
68.0
150.0


58.0

VSS
22.5
9.0
31.8
27.0
22.6
20.0
39.0


16.8

SEC
0.39
0.34
0.30
0.11
0.28
0.11
0.11


0.11
Observed
Problems
! %
5
3.0
3.0
3.4
3.3
3.2
3.2
3.2
2.5
4.0
3.1
5
2.4
2.0
2.0
1.7
2.1
1.5
2.2
1.3
1.0
1.6
I

v>"~ *
a> i- Z>
*J =J C
sss
19.6
3.8
5.8
49.0
11.7
23.1
15.0
0.3

13.2
Hydrology
c
o
ssx
O — «J
••- T> C
*> V « V
So, Is!
Jsl
0.88
0.16
0.27
2.22
0.61
1.14
0.53


0.56
££%
0.32
1.52
3.07
0.12
1.49
0.15
0.25


0.22
JC.
vt
s
n <•-
r-. c
91 >, 3
r* JO &
97.9
53.9
724.8
5.6
233.7
11.0
26.1


20.7
Biota
c
r— O
o> c
1-4 UJ
19.3
4.1
2.1
1.0
6.6

55.1



          •Parameter means were constructed for 6 clusters  and  25 subclusters.
           Parameters, acronyms, and units  are as follows:

           Scaled spectral signature - LANDSAT bands  were scaled (0-100) using
           approach described 1n text.

           1EPA Data (1977) - Data collected by Illinois Environmental
           Protection Agency during summer  of 1977.   TSS -  total suspended solids
           (mg/Hter).  VSS - volatile suspended solids (mg/llter).  SEC -
           Secchl depth (m).

           Observed Problems - Problems noted through field observations and
           adversely affecting use.  Scaled 0-4 with  0=m1n1mal  problem and
           4=severe problem.
NES Data (1973) - Data collected  by U.S.  EPA's National Eutro-
phication Survey in October 1973.   SEC  -  (m).  CHLA  -  dig/liter)
Morphology - Data from 1EPA files.
maximum depth (m).
     I - mean depth (m).   Zm -
Hydrology - Data from 1EPA files.   Watershed equivalent centimeters -
reservoir volume divided by watershed area  (cnrVcm').  Detention
time (years).  Volume loss related  to sedimentation - annual loss of
lake volume expressed as a percentage.   1973 flush by rain runoff -
percent of lake volume replaced  by  runoff from heavy rains just prior
to dates of LANDSAT coverage.
Biota - Data from 1EPA files.
(cells x 1000/ml).
1977 algal  enumeration

-------
 A  B
      AD Algae (1000/ml)
      B E3 Secchi Depth (cm)
          I Total Suspended Solids (mg/l)
      C EH Volatile Suspended Solids (mg/l)
      D[ ] Red Index Reflectance %
  C D
18-
12-
 6-
•10


-50


-90


.130
60-


48-


36-


24-


12-
-60


-50


-40


-30


-20


-10
    Figure 60.
                          2      5
                        Lake Cluster
          Visual correlation between contact-sensed data and scaled
          MSS RED band data at the six-cluster levels.  The parameter
          values are cluster means from the 1977 contact-sensed data.
                              146

-------
E
o
340-


300-


260-


220-
O  140-
o
    100-


     60-


     20-
   Figure 61.
                      • 1973 NES Secchi Depth
                      *1977 Secchi Depth for NES Lake
             10   20
                    30   40   50
60   70
80   90
                       Red Band Index %
         Light extinction relationship between MSS RED band index
         (percent) and Secchi depth measurements taken in 1977.
         The line is a trend line obtained by a visual fit, not a
         regression.
                           147

-------
.*>
00

«••»
\
O)
V)
"o

•o
TJ
c
OJ
a
to
3
15
o
H-


200-i
100-
80-
60-
40-

20-

10-


5-






V-

*.•
%
*1 %
*
.7^
*'4 . .•

0 0
•
+• m . • •

• • ••• •

i i i i i i i i i *
                            40    80   120   160   200   240  260  280   320   400

                                          Secchi Depth (cm)
      Figure 62.  Total  suspended solids relationship with Secchi depth.  Data are mean values for each lake

                sampled during 1977.

-------
spectral  reflectance values increase in cluster order 3-1-2-5-4-6 as  shown  in
Figure 59 and Table 23.  Corresponding increases in  total  and  volatile
suspended solids follow a similar pattern, while Secchi  depths demonstrate  a
progressive decrease in light penetration (Figure 60, Table 23).  Algal  data
for 1977 correlate with the general  pattern found in the field observations of
use impairment and correspond to Secchi and volatile suspended solids data.
Similar trends for Secchi depths and chlorophyll a^ concentrations are evident
in the 1973 NES data, the extensive  ground control data  of 1977, the  use
impairment evaluations, and the spectral  index signatures.

    Chlorophyll a^ levels and algal counts indicate primary productivity
increases from deep lakes to shallow water bodies until  the inorganic
suspensoids decrease Secchi depths below one-half meter.  The  most  turbid
water bodies are encountered in Clusters 4 and 6. These trends suggest  that
user impairment is related to lake morphology and suspensoids. Algal
suspensoids selectively affect shallower water bodies unless sediment-related
turbidities are excessive.  Suspended sediment appears to progressively  impact
use impairment as water bodies become shallower and  ultimately becomes the
single factor determining loss-of-use potential in the worst lakes.
Macrophyte use impairment is most significant in deep, clear waters and
gradually becomes less conspicuous as suspensoids increase and Secchi depths
decrease.

    Thus, suspensoids are a significant factor in determining  Illinois lake
qualities and impairments.  Table 23 summarizes lake morphology and
hydrological information for lake clusters and subclusters to  demonstrate the
obvious relationship of lake morphology to the use impairment  factors
discussed above.  The decrease in mean and maximum depths generally follow  the
established lake cluster order (Table 23) as do the  volatile and total
suspended solids relationships.  Clusters 3 and 1 are deep, clear water  bodies
with well-developed basins, while Clusters 5 and 4 consist of  shallow turbid
lakes.  Cluster 2 is between these.

    Interpolation of hydrological data for these clusters provides  insight  as
to their behavior regarding suspensoid levels and Secchi depths.  Analysis  of
the equivalent flushing rate and normal detention time of lakes indicates that
the concentration of inorganic suspensoids is a function of inputs  from
runoff.  Calculations for detention  times account for the average annual
runoff values (Figure 63) expected for each watershed.  The detention period
for lake clusters decreases in the order 3-1-2-5-4-6, corresponding to the
inorganic suspensoid and MSS reflectance index signature increases  in the same
order.  This inverse relationship of detention time  to lake quality can  be
interpreted as a direct correlation  of lake flushing to  suspensoid  levels and
overall qualities.  Therefore, it follows that shallow reservoirs with large
watersheds will be more severely impaired than deep  reservoirs with long
detention capacity.

    Illinois lakes are significantly influenced by their flushing rates.
Short-detention lakes are of poorer quality, irrespective of appreciable
nutrient inputs, than are lakes with long hydraulic  retention  times.
Therefore, light inhibition may be more significant  in determining  Illinois
lake impairment than the classical nutrient trophic  index procedures.  It

                                     149

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                                                              8
                                                                 :  10
         0 1 10  10
                                                UWMfifTM

                                                      Jr\ . IMODU01I
                                       15
Figure 63.  Average annual runoff  for Illinois in inches/square mile/year
            (Upper Mississippi River  Basin Study Commission 1970).
                                    150

-------
appears that algal  productivity is proportionate to flushing rates  until  the
inorganic suspensions mask the effects of nutrient flushing by restriction  of
the euphotic zone.   Obvious relationships of lake morphology and  watershed
hydraulics to the overall quality of Illinois lakes are summarized  in  Table
23.

    To further examine the relationships between lake quality characteristics
and lake morphology and hydraulic characteristics, equivalent flushing rates
were determined for the clusters from meteor!ogical conditions just prior to
satellite flyover (Figure 64 and Table 23).  The equivalent flush occurring
just prior to the MSS sampling in 1973 does not account for the good-to-
excellent quality water bodies of Clusters 3, 1, and 2 since those  were not
flushed by significant amounts of runoff prior to sampling.  Clusters  4 and 5,
on the other hand,  were flushed by significant amounts of runoff  and are
comprised of lakes with poor water quality.  The general  flushing trend
increases in cluster order 3-1-2-5-4-6 and corresponds to higher  suspensoid
loads than expected for annual watershed equivalent centimeter volumes and
detention times.  The rainfall amounts that occurred during October, 1973,
were not unusual for this time of year.

    Volume loss estimates given in Table 23 relate to morphology  and hydrology
of the lake and its watershed.  Watershed physiography, geology,  and soil
types affect the sediment impact.  Discussion of these factors and  their
bearing on the lake clusters is given in the detailed lake cluster
descriptions.  Volume loss from sedimentation can be misleading because this
figure represents a percent loss by lake volume and not a concentration in  the
water column.  In addition, lakes having larger watersheds generally have
proportionally lower sedimentation losses because less sediment reaches the
reservoir.  Sediment-trap efficiency decreases as the reservoir capacity
decreases, and consequently an increased amount of sediment is passed  through
the reservoir outlet.  Thus, long-detention lakes may have greater  trap
efficiency and higher volume losses than short-detention lakes, even though
their loadings are similar.

Lake Cluster Characteristics--

    Table 23 lists representative data for the lake clusters.  In addition,
values for subclusters were included to indicate the variability  of lake  types
within a cluster.  Appendix A-5 gives individual data for each lake within  the
clusters and subclusters.  The lake classification developed by this effort
generally is based upon the physical properties and characteristics of lakes.
This approach provides an objective comparison of the water transparency  as it
is affected by weed growth, nuisance algal blooms, impaired water quality,
sediment infilling, and turbidity.  These problems are directly related to
impairment of use and do not consider the nutrient budgets as a means  to
characterize lakes in Illinois.

    The following discussion provides a characterization of the lake clusters
established by spectral responses.  The agreement of ground truth information,
subjective observations of lake problems, watershed characteristics, and  lake
morphology suggest the approach is valid.  Watershed geology and  soil
associations are included in the analysis.

                                     151

-------
                 ^ J., 0.-~, I s,,^,..,,! „.
Figure 64.  Distribution of  precipitation In centimeters for Illinois
            for the period October 11-14, 1973.  Data from Environmental
            Data Service (1973).


                                  152

-------
    Cluster 3 characteristics--This cluster generally  represents  lakes  in
Illinois having excellent characteristics and associated  trophic  qualities.
The average depth of visibility (Secchi depth)  is 1.43 m.  Volatile  suspended
solids comprise over 80 percent of the total  suspensoids  by weight,  indicating
that most of the light-extinction properties are of organic origin.   The TSS
values are the lowest recorded for all lakes.

    Field evaluations of lake conditions demonstrated  that sediment-related
turbidities are minimal.  Some problems occur as a result of algal blooms.
Macrophyte growths are moderate and may be associated  with the  relatively
clear waters in these lakes.

    The cluster includes most of the good quality, natural glacial lakes of
less than 100 surface hectares in the Great Lakes section of the  Central
Lowland province (Figure 2).  Most other lakes in this cluster  are small-to
medium-size south-central or southern Illinois impoundments in  the Tills
Plains section and are associated with weathered Illinoian glacial drift
deposits (Figure 2).  Their watershed soils are generally low in  productivity,
with less than one percent organic matter, and are light-colored  with high
clay content.

    Cluster 3 lakes are generally deep (for Illinois)  and well  developed,  with
the mean depth for the group averaging 4.12 m and the  maximum depth  averaging
11.46 m.  The average lake volume, expressed as watershed  equivalent
centimeters (reservoir volume divided by drainage basin area (cm3/cm2)),
is over 53.8.  This high value represents lakes having average  detention
periods of 2.25 years, generally ranging between 0.5 and 9 years.  Rainfall
prior to satellite flyover was equivalent to an average volume  displacement  of
19 percent for all lakes in this group.  This value represents  the  lowest
equivalent displacement of all clusters.  The watersheds generally  have less
than 1.25 m of loess deposits.  The long detention periods and  watershed soil
types result in an estimated annual lake capacity loss from sediments of 0.32
percent.

    Cluster 1 characteristics—This cluster represents lakes of good quality
associated with moderate sediment, algal, and macrophyte problems.   The
average Secchi depth is slightly less  than Cluster 3 lakes, although the
organic suspensoids  remain constant.   The moderate increase in total suspended
solids, when compared to Cluster 3 lakes, indicates increased inorganic
turbidities and losses of light penetration.  Field observations suggest that
the more  sparse macrophyte  growths are primarily the result of increased
sediment-related turbidity  levels  in  this group.

    This  group of  lakes has  a mean depth averaging 4.42 m  and a maximum depth
averaging  11.58 m.   Although their morphology is  similar to Cluster 3 lakes,
this  group has larger watersheds.  The average  lake volume, expressed as
watershed  equivalent centimeters,  is  less than  34.8.   The  average lake
detention  period  is  1.46 years  and generally  is  from 0.3 to 6 years.  Rainfall
prior to  satellite flyover  represented an average  volume  displacement of
nearly  30  percent, a significant  increase over  Cluster 3  lakes.  Annual
average lake  capacity  loss  from sediment  is  estimated  to  be approximately
0.16  percent.

                                      153

-------
    Most of these lakes have watersheds in glacial drift generally associated
with loess deposits of less than 1.25 m.  All lakes are either natural glacial
lakes, gravel pits, or artificial reservoirs.  The reservoirs vary from 19 to
2,953 ha and generally are associated with Illinoian glacial drift of the Till
Plain section.  In general, sediment, algae, and macrophyte problems are
slight to moderate.

    Cluster 2 characteristics—Cluster 2 lakes are similar to Cluster 3 and 1
lakes except that their water quality is lower.  Moderate turbidity and algae
bloom problems occur.  Macrophyte abundances are not excessive, a consequence
of the turbidity conditions.  These lakes have almost twice the concentrations
of both total and volatile suspended solids and are associated with a
40-percent decrease in the depth of visibility when compared to Cluster 3
lakes.  Sediment-related turbidity problems appear to contribute to the Secchi
depth average of less than one meter.  The NES chlorophyll a_ values suggest
that algal problems are progressively worse from Cluster 3 to 1 to 2;  changes
in  volatile  suspended solids values for these clusters qualitatively
correspond to changes in chlorophyll values.

    This  group of lakes has a mean depth averaging 2.4 m and a maximum depth
averaging 6.1 m.  The average lake volume, expressed as watershed equivalent
centimeters, is about 23.  The detention period ranges from 0.4 to 2 years and
averages  0.9 years.  Thus, these lakes have significantly shorter detention
times than the previous clusters.  Rainfall prior to satellite flyover
represented  an average volume displacement of about 25 percent.  Although this
average displacement value is less than the Cluster 1 value, the individual
lake  values  in Cluster 2 lakes varied less.

    Lakes in Cluster 2 include natural glacial flowage lakes known to be
turbid and productive, shallow natural glacial lakes, several river
backwaters,  and artificial reservoirs.  Most of the reservoirs have watersheds
associated with Illinoian glacial drift with loess deposits having
light-colored soils with less than 1 percent organic matter.  Average annual
lake capacity loss from sediment is estimated at 0.14 percent.

    Cluster 5 characteristics—This cluster represents lakes having moderate
to severe sediment-related turbidities and algal blooms and moderate
macrophyte growths.  In general, inorganic and organic suspensoids are high.
The volatile suspensoids account for nearly two-thirds of the total
suspensoids, which are nearly four times those found in the best quality lakes
(Cluster 3).  Secchi depth averages about 0.6 m, as compared to 1.4 and 0.9 m
for Clusters 3 and 2, respectively.

    This group of lakes has a mean depth averaging 1.8 m and a maximum depth
averaging 4.3 m.  It includes natural backwater lakes in the bottom lands with
alluvium and no loess deposits, as well  as sloughs and artificial reservoirs.
The reservoirs have an average lake volume of about 13, expressed in watershed
equivalent centimeters.  Detention periods generally range from .007 to 2
years and average 0.69 years.  Rainfall  prior to satellite flyover represented
an average volume displacement of about 143 percent.  This value represents a
significant displacement for reservoirs.


                                     154

-------
    Ground samples during 1977 indicated that the deeper reservoirs are
generally clear waters except after high runoff periods.  The  average annual
lake capacity loss from sediments is estimated to be 0.72 percent.  The
backwater areas receive overflows from the adjacent rivers and have turbid
waters of poor to fair quality.  Reservoirs deeper than  4 m are considered to
be fair to good quality lakes, while the shallower reservoirs  are generally
of poor quality.

    Cluster 4 characteristics—This cluster represents lakes having severe
sediment-related turbidities, moderate algal bloom problems, and minimal
macrophyte problems.  Secchi depth is less than 0.3 m, or less than one-half
the depth observed in Cluster 5 lakes.  The total suspended solids of Cluster
4 lakes is double the average for Cluster 5, although the volatile
suspensoids are at about the same level.  The significant decrease in depth
of visibility corresponds with the increase in sediment.

    This group of lakes has a mean depth averaging 2.4 m and a maximum depth
averaging 4.9 m.  Most of the artificial reservoirs drain watersheds of
Wisconsin glacial drift with less than 1.25 rn of loess deposits. Their  soils
are dark-colored and productive and have more than 1 percent organic matter.
The average lake volume, expressed in watershed equivalent centimeters,  is
only 5.8.  The detention period ranges from 0.002 to 0.546 years.  Rainfall
prior to satellite flyover represented an average volume displacement of
nearly 360 percent.  The annual lake capacity loss from sediment ranges
between 0.06 and 8.5 percent and averages about 1.8 percent.  The quality of
the reservoirs is considered fair, while the natural backwaters are  in  poor
condition.  These lakes do not have excessive macrophyte growth problems.
Field observations suggest this is primarily because of the sediment-related
turbidity.

    Cluster 6 characteristics—Cluster 6 lakes are generally of poor  quality,
with severe sediment-related turbidity problems.  The group is composed  of
many shallow-river backwater lakes as well as harbors or artificial
reservoirs experiencing significant sedimentation problems.  Contact-sensed
data are limited to four lakes.  Two reservoirs sampled in 1977 had  low
suspensoids loads and good Secchi depth readings but are known to  have
experienced severe suspended solids problems in the past.  Both watersheds
have more than 1.25 m of loess deposits.  The two backwater lakes  sampled
during 1977 exhibited extremely high suspended solids values.   The TSS  value
for Meredosia was 150 mg/liter, the highest value recorded for any  lake
sampled during 1977.  Most of the natural backwater lakes in this  group
occupy the glacial outwash area adjacent to the  Illinois River.  These
lateral levee lakes have been severely  impacted  by drainage improvements,
levee construction, river dam construction, navigation, and silt deposition.
Lack of water clarity is the  result of  suspended sediment from flowage  and
resuspension of  flocculent bottom materials.  Prior to  their deterioration,
these bottom land lakes  supported luxuriant macrophyte  populations  and  fish
and invertebrate fauna.
                                      155

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LANDSAT-Estlmated Trophic Indicator Classification  of the  Lakes

    In the preceeding subsection the dendrogram generated  from the
date-adjusted LANDSAT spectral  data for the 145 water bodies  was  interpreted.
In this subsection, the results of a parallel  effort  that  employed
LANDSAT-derived trophic indicator estimates will  be interpreted.  Clustering,
using trophic indicator estimates derived through conventional lake  sampling
techniques as attributes, is a  well-accepted approach.  In this case
clustering is based on attributes (i.e., trophic indicators)  estimated  from
the LANDSAT data set.

    Four of the trophic indicators (SEC, TPHOS, TON,  and CHLA) estimated  by
the three sets of regression models were selected for cluster analysis.
Separate clustering runs were made for each data set  using two programs
(CLUSTER, a SAS program on COMNET, and CLUSTER, a program on  Oregon  State
University's Cyber 73).  While both programs are of the complete  linkage
type, their hard-copy products and cluster results  are similar though not
identical.

    The regression results indicate that the Set One models are  least
satisfactory and that the Set Three models provide  the best overall
estimates.  The following interpretation is limited to the Set Three
12-cluster table (Table 24) generated by the SAS program on COMNET.
Limnologists found the 12-cluster classification to be more satisfactory  than
the other groupings examined (e.g., 6- and 9-cluster classifications).

Lake Cluster Character! stics--

    In the following subsections an interpretation  is made of the 12-cluster
SAS program output (Table 24).  The cluster characteristics,  as  evidenced by
the 1973 and 1977 contact-sensed data, are given in Table 25.  Appendix
Tables A-2, A-3, and A-5 list the contact-sensed data for each  lake within
the clusters.  The interpretation is made by comparing:  1) trophic indicator
estimates with 1973 NES data; 2) trophic indicator  estimates with the 1977
lake water quality data; and 3) the trophic status  of the clusters with each
other.  Clusters are described  in order of increasing eutrophy as determined
by estimated values for SEC, TON, TPHOS, and CHLA.   Terse descriptions for
each group are based on cluster means established from estimated values for
SEC, TON, TPHOS, and CHLA.

    Trophic class number 1  (Cluster 8)—Terse description:  (very high SEC,
low TON, TPHOS, and CHLA).  Lake Kinkaid (serial number 40), a southern
Illinois  reservoir and the  only lake in this class, has excellent water
quality  (at least for  Illinois  lakes) with minimal  sediment-related turbidity
and algal blooms.  The aquatic  macrophyte  problem  is  rated as slight.
Results  of  IEPA summer 1977 sampling for TSS, VSS, and SEC averaged
1.0 mg/liter,  0.0 mg/liter, and 1.97 m, respectively.  Lake Kinkaid has a
mean  depth  of  8.7 m  a"nd  a maximum  depth of 24.4 m;  water  retention time is
1.72 years.
                                      156

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TABLE 24.  TROPHIC CLASSES DEVELOPED FROM CLUSTER ANALYSIS OF TROPHIC
           INDICATOR ESTIMATES FROM SET THREE REGRESSION MODELS
Name
Class 1 (Cluster 8)
Kinkaid
Class 2 (Cluster 7)
Lincoln Trail
Sara
Little Grassy
Devil 's Kitchen
Glen 0. Jones
Coal City Recreation
South Wilmington
Thunderbi rd
Murphysboro
Dutchman
Bracken
St. Mary's
Olney East Fork
Lake of Egypt
George
Mesa
Sand
West Loon
Deep
Class 3 (Cluster 5)
Paris Twin
Spring Arbor
Olney New
Moses
West Frankfort New
Cedar
Gages
Catherine
Zurick
Storey
Serial Number

40

13
26
119
128
110
138
140
173
37
49
145
146
106
132
108
184
147
156
150

25
143
107
28
31
55
152
58
154
50
County

Jackson

Clark
Effingham
Williamson, Jackson
Wi 1 1 i amson
Saline
Grundy
Grundy
Putnam
Jackson
Johnson
Knox
Lake
Richland
Johnson, Williamson
Rock Island
Wabash
Lake
Lake
Lake

Edgar
Jackson
Richland
Franklin
Franklin
Lake
Lake
Lake
Lake
Knox
                                                                  (continued)
                                    157

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                            TABLE 24. (continued)
Name
Serial Number
   County
Crab Orchard
East Loon
Summerset
Channel
Pierce
Sam Dale
Highland
Countryside
     127
      53
     186
      59
     130
     124
     153
     148
Williamson
Lake
Winnebago
Lake
Winnebago
Wayne
Lake
Lake
 Class 4  (Cluster 6)

 Carlyle
 Mattoon
 Canton
 Commonwealth  Edison-Dresden
 We-Ma-Tuk
 Cedar
 Vandalia (City)
 Rend
 Shelbyville
 Wolf
 Stephen  A.  Forbes
 Apple Canyon
 McCullom
 Centralia
 Bangs
 Round
 Crystal
 Diamond
 Pana
 Argyle
 Paradise
 Big
 Upper Smith
 Spring
 Little  Swan
 Big
 Raccoon
 Quiver
 New Pittsfield
 Pistakee
      14
      24
      36
      137
      33
      39
      27
      29
      114
      17
      78
      144
      159
      79
      56
      66
      68
      57
      113
      157
      15
      176
      180
      67
      185
      134
      80
       90
      100
       65
Clinton, Bond, Fayette
Cumberland
Fulton
Grundy, Will
Fulton
Jackson
Fayette
Franklin, Jefferson
Shelby, Moultrie
Cook
Marion
Jo  Daviess
Me Henry
Marion
Lake
Lake
Me Henry
Lake
Shelby,  Christian
McDonough
Coles
Schuyler
Scott,  Morgan
McDonough
Warren
Brown
Marion
Mason
Pike
Lake, McHenry

              (continued)
                                      158

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                            TABLE 24. (continued)
Name
Serial Number
  County
Powerton Cooling
Pinckneyville
Lower Smith
     182
      99
     181
Tazewell
Perry
Scott
Class 5 (Cluster 4)

Spring
Charleston
Clear
Chautauqua
Anderson
Fourth Lake
Meredosia
Calumet
Chain
Matanzas
Sugar Creek
Old  Ben Mine
Harrisburg
Snyder's  Hunting
Griswold
Fyre
Sanganois
Crane
Long
Moscow
Yorkey
Pekin
Kinneman
Lily
Lyerla-Autumnal
Tampier
Otter
 Sunfish
 Liverpool
 Bath
 Swan
 Sahara Coal Company
 Goose (Village Club)
       8
      16
      86
      87
      34
     151
      10
      18
      83
      89
     178
      32
     111
     142
     158
     170
        9
      85
     177
     164
     179
     116
      168
     136
      120
       23
      167
      126
       88
      166
       93
      175
      139
Carrol 1
Coles
Mason
Mason
Fulton
Lake
Cass, Morgan
Cook
Mason
Mason
Schuyler
Franklin
Saline
Jackson
MeHenry
Mercer
Cass
Mason
Schuyler
Mason
Schuyler
Tazewel1
Massac
Cass
Union
Cook
 Mason
 Whiteside
 Mason
 Mason
 Mercer
 Saline
 Grudy
                                                                    (continued)
                                      159

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                            TABLE 24. (continued)
Name
Serial Number
County
Class 6 (Cluster 1)
Horseshoe
Worl ey
Cattail
Bakers
Keithsburg
Open Pond (Marshy)
Lake of the Woods
West Frankfort Old
Marion
Sam Parr
Greenville New City
Nippersink
Decatur
Long
Fox
Grass
Petite
Hoi id ay
Third
DePue
Jack, Swan, and Grass
Crooked
Carbondale
Rice
Marie
Spri ng
Senachwine
Mound
Class 7 (Cluster 2)
Spri ng
Skokie Logoons
Turner
Class 8 (Cluster 3)
Saganashkee
Marshall

1
117
125
19
92
174
115
30
129
41
2
63
73
52
60
61
64
51
155
3
165
149
38
35
62
118
104
163

4
22
102

21
81

Alexander
Tazewel 1
Whites ide
Cook
Mercer
Saline
Tazewel 1
Franklin
Wi 1 1 i amson
Jasper
Bond
Lake
Macon
Lake
Lake
Lake
Lake
LaSalle
Lake
Bureau
Mason
Lake
Jackson
Fulton
Lake
Tazewel 1
Putnam
Mason

Bureau
Cook
Putnam

Cook
Marshal 1
                                                                  (continued)
                                     160

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                            TABLE 24.  (continued)
Name                             Serial  Number           County
DuQuoin                                98              Perry
Goose                                 100              Putman,  Bureau
Swan                                  172              Putnam
Class 9 (Cluster 11)

Wonder                                 69              McHenry


Class 10 (Cluster 12)

Sawmill                               103              Putnam


Class 11 (Cluster 9)

McGinnis                               20              Cook
LaRue-Pine Hills                      121              Union


Class 12 (Cluster 10)

Slocum                                 54              Lake
     Trophic  class number  2  (Cluster 7)--Terse description:  (high SEC, low
 TON, TPHOS,  and  CHLA).  Most  of the 19 Takes in this group are artificial
 reservoirs  in  northern  and  southern Illinois of good to excellent water
 quality;  these lakes  exhibit  little use  impairment from sediment-related
 turbidity,  algae, or  aquatic  macrophytes  as assessed by IEPA  (1978a).  The
 mean depth  for the  cluster  averages 5.7 m and the maximum depth averages
 13.8 m.   The average  detention time for  this group is  3.45 years.  These
 lakes are generally clear with very low  suspended solids levels.  The summer
 1977 sampling  by IEPA produced mean values of 3.7 mg/liter, 2.7 mg/liter, and
 2.06 m for  TSS,  VSS,  and  SEC, respectively, for this group.

     Trophic class number  3  (Cluster 5)—Terse description:  (average SEC,
 TON, and CHLA, slightly low TPHOS).   This class contains southern and
 northern reservoirs and glacial  lakes of good quality  with little use
 impairment  from  sediment-related turbidity.   Algal bloom problems are slight
 with aquatic vegetation problems ranging in severity from slight to moderate.
                                      161

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                     TABLE  25.   INTERPRETATION OF  CLUSTERS DEVELOPED  FROM  SET THREE  REGRESSION  MODELS*
                                      Observed
                                      Problems
                                        NES Data
                                         (1973)
IEPA Data
 (1977)
                                                                                                                   Hydrology
                                                                                                                    Set  Three Models
Cluster             •£
Number              |
 and     Perceived   r:
(Obs.)    Quality    «
                                              I  0)
                                              O 4->
                                              I- >>
                                          3   2
                                                                                                   Morphology
                                                                                               3
1
2
3
4
5
6
7
8
9
10
11
12
8 ( 1)
7 (19)
5 (18)
6 (33)
4 (33)
1 (28)
2 ( 3)
3 ( 5)
11 ( 1)
12 ( 1)
At V A /
9 ( 2)
y \ t. y
10 ( 1)
1.0
1.6
2.1
2.4
3.4
3.1
4.0
3.0
3.0
4.0
3.0
4.0
1.0
1.3
1.7
2.3
3.1
2.8
3.5
3.0
3.0
4.0
1.5
4.0
1.0
1.7
2.4
2.1
1.9
2.8
1.7
2.3
3.0
l n
3 5
4.0
2.0
2.4
2.6
2.0
1.7
1.9
1.7
2.0
3.0
1 0
4.0
1.0
- 1.97 0.01 0.13
- 1.83 0.03 0.03
1.23 27 0.10 1.08 0.95 0.07 0.19
0.58 21 0.12 0.92 1.05 0.06 0.18
0.25 18 0.21 1.20 0.31 0.25 1.94
0.37 49 0.37 1.59 0.74 0.48 0.79
- 0.25 1.17 0.10
- 0.28 0.42 0.13
0.46 198 0.42 1.79 0.31 0.61 0.16


0.31 241 1.33 5.94 0.34 1.50 0.57
1
5
10
19
55
32
37
62
49


25
0
4
8
8
22
19
22
24
16


21
264
1,022
4,689
3,290
35,648
5,106
13,824
1,280
2,247


30,465
8.7
5.7
3.0
3.1
1.6
2.0
.8
1.2
2.0

0.5
1.2
24.4
13.8
9.8
8.9
3.8
5.2
1.8
4.5
10.4

1.5
2.7
56.9
81.4
28.1
34.3
29.2
41.8
.
9.2
12.6

9.0
4.8
1.72
3.45
1.14
1.35
1.28
1.86
.
.39
.62

.45
.24
7.42
1.84
1.03
0.68
0.35
0.43
0.28
0.32
0.31
0.17
0.27
0.34
1
10
2b
17
23
42
42
74
158
143
109
229
0.41
0.82
1.22
0.89
1.20
1.52
2.12
1.91
2.07
3.00
4.69
5.12
0.02
0.11
0.2U
0.15
0.36
0.38
0.7b
0.51
0.47
0.91
1.60
1.43
01
ro
            Parameter means were constructed  for  12 clusters.
            Parameters, acronyms, and units are as follows:
            Trophic Class - based on cluster  means of estimated values  for SEC,
            TON, TPHOS, and CHLA,  Scaled  1 - 12  with 1 = least eutrophic and
            12  = most eutrophic.

            Perceived quality - Summary of quality based upon analysis  of
            information from a variety of  sources.  Scaled 1-4 with  1 =
            very good and 4 = very poor.

            Observed Problems - Problems noted through field observations and
            adversely affecting use.  Scaled  1-4 with 1 = minimal  problem and
            4 = severe problem.

            NES data (1973) - Data collected  by U.S. EPA's National  Eutrophication
            Survey  In October 1973.  SEC - (meters).  CHLA - (Mg/liter).  TPHOS -
            mg/liter).  TON - (mg/Hter).
                                                                     IEPA Data (1977)  -  Data collected by Illinois  Environmental Protection
                                                                     Agency during summer of 1977.  TSS - total  suspended solids (rig/liter).
                                                                     VSS - volatile suspended solids (mg/liter).  SEC  - Secchi depth
                                                                     (meters).  TPHOS  -  total phosphorus (mg/liter).   IN - inorganic nitrogen
                                                                     (mg/liter).   Algae  - algal enumeration (cells  x 1000/ml).

                                                                     Morphology - Data from IEPA files.  7 - mean depth (meters).  Zm -
                                                                     maximum depth (meters).

                                                                     Hydrology -  Data  from IEPA files.  Detention time (years).

                                                                     Set Three Models  -  cluster means based on parameter estimates generated
                                                                     from the third set  of regression models.  SEC  - Secchi depth (meters).
                                                                     CHLA - chlorophyll  & (ug/Iiter).  TON - total  organic nitroyen
                                                                     (mg/liter).   TPHOS  - total phosphorus (mg/liter).

-------
Mean depths for the group average 3.0 m, while maximum depths  average 9.8 m.
Water detention time averages 1.14 years for the group.   According to IEPA
1977 summer sampling data, the average amount of total and volatile  suspended
matter is three times that of trophic class 2, resulting in a  50  percent
decrease in Secchi transparency.

    Trophic class number 4 (Cluster 6)--Terse description:  (low  SEC, TON,
TPHOS, and CHLA).The 33 water bodies in this category include reservoirs
from throughout the State, glacial lakes, and backwaters, ranging in water
quality from fair to good.  Sediment-related turbidity is a slight to
moderate problem.  Algal blooms are a slight problem.  Aquatic macrophyte
problems are minimal.  The mean depth of the cluster members is 3.1  m,  while
the maximum depth averages 8.9 m.  Average water detention time is  1.35
years.  Average water transparency and volatile suspended solids
concentrations for this group in 1977 were approximately the same as trophic
class 3, while the inorganic suspensoid level is three times that of the
previous class.

    Trophic class number 5 (Cluster 4)--Terse description:  (low  SEC,
slightly low TON and CHLA, average TPHOS).  Most of the 20 water  bodies
included in trophic class 5 are river backwaters or bottom land lakes  that
are shallow and turbid.  Mean depth for the group averages 1.6 m, while
maximum depth averages 3.8 m.  Most are of poor to fair quality with severe
sediment-related turbidity problems.  Algal problems are  slight and aquatic
vegetation is minimal, largely a consequence of the light  inhibition by
suspended sediment.  Summer 1977 sampling data for total  and volatile
suspended solids  show a three-fold increase over the  previous trophic  class,
resulting in a three-fold reduction in Secchi transparency.

    Trophic class number  6 (Cluster 1)—Terse description:  (low SEC,  average
TON,  TPHOS, and  CHLA).  This class is represented by  river backwaters,
reservoirs located throughout the State, and glacial  lakes.  Most of the
water bodies are  of  fair  quality with sediment-related  turbidity problems
ranging  from slight  to  severe.  Algal bloom  problems  range in severity from
slight to moderate.  Use  impairment from aquatic macrophytes  is minimal.
Summer 1977 sampling results for  total  and  volatile  suspended solids and
Secchi depth for this class  fall  between the  average  values for trophic
classes  4  and  5.

    Trophic class number  7  (Cluster  2)—Terse  description:   (low SEC,
moderately  high  TON  and TPHOS,  average  CHLA).   The three  water bodies  in this
class represent  a glacial  lake,  a former sewage lagoon, and a  river
backwater.  These shallow water bodies  are of  poor quality.   Severe
 sediment-related turbidity and  algal  bloom problems  exist. Vegetation
 problems are minimal.   This  class,  as well  as the  remaining five trophic
classes,  had high suspended  solids  levels  and low  Secchi  transparency  in the
 lEPA's  1977  summer sampling.

     Trophic  class number 8 (Cluster 3)--Terse description:  (low SEC,
 moderately high TON and TPHOS,  very high CHLA). This group  consists of three
 river backwaters, a northern slough,  and a southern  reservoir.   As  presently
                                      163

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constituted, quality of these shallow, short-detention water bodies ranges
from poor to fair.  Sediment-related turbidity ranges from minimal  to
moderate.  Algal blooms and aquatic vegetation present slight use impairment
problems.

    Trophic class number 9 (Cluster 11)—Terse Description:  (low SEC,
moderately high TON and TPHOS, very high CHLA).  The single water body  in
this class is a shallow, short-detention, northern reservoir, Wonder Lake
(serial number 69). Sediment-related turbidity, algal blooms, and aquatic
macrophytes all present moderate use impairment problems for this lake.

    Trophic class number 10 (Cluster 12)—Terse description:  (low SEC, high
TON and TPHOS, very high CHLA).Sawmill Lake (serial number 103) is a  river
backwater of poor quality as evidenced by severe use impairment problems from
sediment-related turbidity and algal blooms.  Aquatic vegetation problems are
minimal.

    Trophic class number 11 (Cluster 9)—Terse description:  (low SEC,  very
high TON and TPHOS, moderately high CHLA).  This group consists of La
Rue-Pine Hills Swamp (serial number 121), in southern Illinois, and McGinnis
Slough (serial number 20), in northern Illinois.  Quality of these shallow
water bodies is rated as fair with moderate to severe algal blooms, moderate
aquatic macrophyte problems, and minimal to slight sediment-related
turbidity.

    Trophic class number 12 (Cluster 10)—Terse description:  (low SEC, very
high TON, TPHOS, and CHLA).  Slocum Lake (serial number 54) is a shallow,
short-detention, northern Illinois reservoir noted for its poor quality.
Severe sediment-related turbidity problems and algal  blooms are known to
exist.  Aquatic macrophytes present a minimal  problem.  Summer 1977 sampling
results indicate that practically all of the turbidity is caused by organic
particulate matter.

GENERAL DISCUSSION

    Although LANDSAT had been used successfully several  times in studies of
lake eutrophication, and statistically significant relationships between MSS
data and lake water quality parameters have been demonstrated, it was not at
all certain that such relationships or correlations would eventually be
obtained for Illinois lakes.  While many of the lakes included in LANDSAT
investigations (e.g., Boland 1976) were characterized by low suspended  solids
and color, Secchi  depths greater than several  meters, and low to high
nutrient concentrations, most Illinois lakes are characterized as turbid with
high sediment loads, low mean morphometric and Secchi depths, very  high
nutrient levels, and short hydraulic retention times.  Indeed, whereas  many
of the lakes studied previously with LANDSAT have primary production that is
nutrient limited,  most Illinois lakes are nutrient rich, but light  poor, as a
result of turbidity from suspended inorganic and organic particulate matter.

    A major consequence of sediment pollution  in Illinois lakes, as it
relates to MSS data, is that the majority of observed chemical  values are
represented within a small  range.  Further, some of the  lakes have  extreme


                                     164

-------
levels for some contact-sensed parameters, which are not readily measured
with the multispectral scanner.  Lake parameters operate over a very  large
dynamic range in comparison with the range of the MSS.   Consequently,
analysis of MSS data and lake properties is more sensitive to changes  in
midrange values.  In spite of this loss in statistical  sensitivity, MSS data
were used to cluster lakes into physically significant  groups and  to  estimate
trophic parameters from which clusters were developed.

     It is not surprising, therefore, that Set One models, employing  raw MSS
data to estimate trophic index parameters, are the least reliable, while Set
Three models, employing an expansion that makes the MSS data uniform  over  its
entire range, are best.  That is, as the concentration increases  at a given
wavelength, the optical density (reflectance) falls off nonlinearly,  with  the
slope rising fastest at low densities and falling off to near zero at high
densities; the optical density scale is logarithmic.  The technique used  in
developing Set Three models, of converting optical densities to ranks,
linearizes the slope over the entire range of lakes.  Provided that the
optical density remains single-valued in the tails and that some
discrimination remains, conversion to ranks should be satisfactory, as has
been observed.

    The application of clustering algorithms to the raw LANDSAT multispectral
data proved to be a viable approach, resulting  in lake clusters with their
own spectral  properties and physically  significant characteristics.  It
permited the  selective comparison of four band  readings, allowing an
objective differentiation of water types according to signatures based on a
spectral index.   In general, increases  in spectral responses  in any MSS band
or  combination of bands are associated  with greater suspended or soluble
material levels and poorer water  quality.  Lakes  having similar spectral  band
DN  readings are closely related in physical and chemical quality.  Although
actual  concentrations  of  non-sensible constituents are  difficult to
accurately  predict from the LANDSAT  MSS data, the spectral  responses of the
lakes  demonstrate general trends  with the contact-sensed data.  The
application of  a  clustering algorithm to  the  spectral data  in an  unsupervised
mode  has much intuitive appeal;  it  is  simple  and  deals  directly with the
spectral characteristics  and physical water  properties  of the lakes.

    The application of clustering algorithms  to lake attributes whose values
have  been  estimated through  regression  models incorporating the LANDSAT MSS
bands  as  independent  variables is attractive  because a  statistically
significant relationship  has  been demonstrated  to exist between the  contact-
sensed and  remotely sensed  data.   However,  at least  in  this study,
superimposed  on the estimated values of the attributes  is  a substantial
amount of  unexplained variation.   Clustering on such  data sets results in
groups or clusters  whose  memberships become increasingly suspect  as  the
 unexplained variation associated with the regression  modeling efforts
 increases.   Conversely,  the more adequate the regression models,  the more
confidence can be placed  in the membership of the individual cluster.

     Whether clustering on spectral attributes  (e.g.,  LANDSAT bands)  or
 trophic attributes  (e.g., trophic indicators estimated by regression on
                                      165

-------
LANDSAT bands), the type of clustering method selected will,  to  some
undefined degree, mold the character of the final  output.   We know  of  no
systematic study that has attempted or is attempting to compare  lake
classifications derived from different SAHN methods.  Standardization  and
transformation techniques also affect the resulting classifications; this  is
another area in which little systematic work has  been done using lakes.

    While it is evident in light of the above discussion that each  clustering
method has a bias, the clusters developed in this study can be interpreted in
"real world" terms.  It is clear from our analyses that Illinois lakes
represent a much greater diversity of waters than is generally recognized.
Further, although a great many of these are "polluted" in the sense of high
nutrient enrichment, it is also true that some are "clean water" waters,  with
aesthetically pleasing qualities.  Further, Illinois lakes offer the
recreationist diversified opportunities ranging from canoeing, boating,  and
swimming, to fishing, trapping, bird watching, and wildlife observation.

    More pragmatically, cursory comparisons of the 1973 and 1977 data  bases
show few general changes, either for the better or worse, in these
impoundments.  Since lakes are dynamic, and Illinois lakes with their
relatively short detention times particularly so, it is suggested that lake
hydraulic and morphologic factors and land use factors that determine  lake
water quality, in part, have remained relatively unchanged during the  period.
Stream water quality, by contrast, has improved overall since 1973  (Hudson et
al.  1978).

     There are several advantages to using LANDSAT in place of conventional
lake monitoring.  These include cost, resource requirements, timeliness of
the  data, uniformity, objectivity, and flexibility of data formats.

     The  costs of purchasing the CCT's, extracting the lake pixels and
associated processing, and preparing statistical and photographic displays
for  the  group of approximately 150 lakes averaged under $200 per lake.  A
substantial  portion  of the cost can be attributed to the batch operation mode
used to  extract most of the lake MSS data.   It was very time consuming and
laborious, requiring the  expenditure of many manhours of effort.  With the
current  availability of the interactive programs described earlier in this
report,  substantial  reductions in extraction costs occur, accompanied by a
major  reduction  in  turnaround time. A  supplemental  LANDSAT study of 60
Illinois lakes cost  about $80 per lake for  MSS processing.   Total costs will
probably not exceed  $250  per  lake.

     If relative  lake information  is  required,  standard, low-cost, readily
available,  statistical  computer  programs can be  used  to analyze the spectral
data.   If trophic  indicator information  is  required,  some contact-sensed
 information  would  have  to be  acquired  at the time  of  the  satellite's  passage
over the State.   Using  the methods  described in  this  report,  estimates of
average  lake water quality could  be  obtained.  We  estimate the total  per  lake
cost of  the present project at $500,  and a  total  project  cost of $75,000,
including preparation of this report.
                                      166

-------
    In contrast to this, the 1977 lake study involving 108 lakes  cost $36,600
for sampling 3 sites per lake and lab analyses.   To this must  be  added  the
costs for the full-time limnologist, data processing and analyses,  and  report
preparation, which are at least equal to the sampling costs.   Therefore,  the
cost per lake for the conventional approach is at least one-third higher  than
the LANDSAT approach.  However, a word of caution is in order  when  examining
such comparisons.  While both approaches (LANDSAT, conventional  field
program) have the same general objective -- the classification of lakes
according to trophic state -- the quality and types of products generated,
the parameters measured and their associated accuracies and precisions, and
temporal efficiencies are generally not the same.  In addition, this was  a
prototype study for the Illinois Environmental Protection Agency.  As  such,
it had a "learning curve" associated with it, lacked the streamlining
characteristic of operational programs, and, therefore, incurred costs  in
time and money that are above those for a program functioning  at an optimal
level.

    This study strongly supports the value and cost effectiveness of LANDSAT
for lake monitoring.  When this is coupled with the sophistication available
in false-color imagery, many specific questions about the instantaneous or
dynamic conditions of selected lakes can be examined.  This project has
served to increase our understanding of a substantial number of Illinois
water bodies.  For the first time a quantitative, geographically
comprehensive understanding of these bodies is available.  As  our
understanding improves, rational  decisions concerning the uses and fates  of
these lakes can be made, costs determined, programs implemented, and benefits
accrued and assessed.

Problems

    By virtue of  its  repetitive coverage, synoptic overview, and ability to
generate permanent records  amenable to  automated  image-processing techniques,
the LANDSAT MSS  is attractive for purposes of environmental assessment and
monitoring.   In  this  study  LANDSAT  provided a view of the past;  it does
provide a monitoring  strategy that  is objective,  uniform, frequent, resource
tolerant, and cost effective  for  the future.  However,  LANDSAT is not  a
panacea; it has  limitations  and problems associated with. it.  A  number of
problems were encountered during  the study.   Several  were solved; others,  by
virtue  of their  nature, defied solution.   Not all  are mutually exclusive.
The specific  problems are discussed  in  the following  subsections.

Availability  of  Imagery--

    Ten  LANDSAT  MSS  scenes  are required for  complete  areal coverage of
 Illinois.   This  necessitates that the  satellite  make  three passes over the
State,  once on each  of  three paths  (Figure 19).   In  1973, only LANDSAT-1
coverage was  available  for  the Illinois lakes.   Excluding side overlap,  the
satellite  provided  coverage on a  repetitive 18-day basis.  It  was our
 intention  to  use MSS data  acquired  concurrently  with  one of the  three  NES
 sampling rounds, preferably the  summer round.  The occurence  of  substantial
 areas of cloud  cover in numerous LANDSAT scenes  acquired between April and
 November of 1973 restricted us to the scenes of  October 14, 15,  and 16,  19/J.

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Cloud cover will continue to plague water and terrestrial  studies  dependent
upon LANDSAT data.  Unlike aircraft, LANDSAT is locked into a  fixed flyover
schedule.  Although the problem of obtaining good,  cloud-free  imagery has
been reduced by the presence of two currently operational  satellites
(LANDSAT-2 and LANDSAT-3), it is still a problem of substantial  magnitude.

    The CCT's for the 10 Illinois scenes, not available at the EROS data
Center, had to be generated at NASA-Goddard.  This  process took several
months, with the CCT's for only eight scenes being  generated.   The long  delay
in delivery was a consequence of several factors:

    1.   NASA-Goddard software changes.  The generation of our "historic"
         CCT's from the high-density tapes required that NASA replace its
         currently operational software with that developed at the start
         of the LANDSAT program.  Difficulties were encountered as a result
         of hardware and programmatic changes.

    2.   Deterioration of high density tapes.  Although only about three
         years old, some of the high-density tapes  had degraded in quality
         to the point where reading them became difficult or impossible.

    3.   Unavailability of spacecraft data.  The scene data for scene
         1449-16084 were available, but the spacecraft data necessary
         to calibrate the scene could not be found.

One of the scenes  (1449-16084), arrived without the proper internal
calibration data.  Much time and effort was expended  in attempts to calibrate
and use the data from this scene.  The black-and-white imagery available from
EROS for the  10 scenes (Figures 20, 22-30) was originally generated at
NASA-Goddard  using an electron beam recorder and data on the density tapes.
If the difficulties experienced in having "historic"  CCT's generated from
high density  tapes is typical of that experienced  by  other investigators, the
question to ponder becomes:   "What will the value  of  the archived tapes be a
decade from now?"

Availability  of  Interactive  Image-Processing System--

    At the start  of the  project, we were limited to an image-processing
system that operated  in  a batch mode  (see Section  6).  By virtue of  its
nature,  the process of extracting  the data  for about  150 lakes  (many
appearing  in  two  or more scenes) using  the  batch mode is inefficient both
timewise and  costwise.   The  development  and refinement of the interactive
image-processing  system  (LAKELOC)  has greatly  speeded up the extraction
process.   What initially took  hours now requires but  a few minutes.
Placement at  the  system's controls of an individual knowledgeable  about the
lakes  of Illinois could  improve  its efficiency even more.

Environmental Factors--

     It  is well recognized that the atmosphere  can  have substantial  effects on
the signal  returning  from lakes.   While the MSS  data  were  adjusted to a
                                      168

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common date, October 15, no concentrated effort was mad? to remove
atmospheric effects through the use of theoretical  modeling or empirical
modeling involving terrestrial  or aquatic calibration points.   An unknown
amount of variation, attributable to the variation  in intensity of
atmospheric effects across the LANDSAT scenes, exists in the MSS lake  data.

    During the period of October 11-14, 1973, much  of Illinois experienced
moderate rains (Figure 64).  The amount of precipitation appears to  be normal
for this season.  It is very likely that many of the lakes experienced large
influxes of suspended sediments.  In some cases, a   substantial proportion  of
each lake's volume was displaced by the incoming waters.  The  combination of
inorganic sediment influx and volume displacement did not disrupt the  average
characteristics of the water bodies if comparisons  of the NES  data for the
spring and summer of 1973 with 1577 data are representative of the true
quality.

    At the time of satellite flyover (October 14-16), the solar angle  was
small, measuring between 35 and 38 degrees.  This effectively  reduces  the
amount of light entering the water body, and consequently the  intensity of
the return signal is less than at higher solar angles.  This makes the
spectral distinction between lake types a more difficult task  because  there
are fewer DN levels.

    The season during which the spectral data are collected has some
relationship to the degree of success experienced by LANDSAT-oriented  lake
classification projects.  As suggested by Rogers (1977) and others,  success
is most likely when the secondary manifestations of eutrophication  (e.g.,
turbidity, algal blooms, macrophyte beds) are most evident.  In Illinois
water bodies, July and August are probably the best period for attempting
satellite-based classifications.  Unfortunately, this project  was limited  by
cloud cover and NES sampling dates to the middle of October.

Contact-Sensed Data--

    The NES data were collected without any thought being  given to their use
in a satellite-related lake classification project.  Hence, sample site
selections were not always optimal in location or number for use with LANDSAT
data.   In addition, field notes regarding phenomena of  special interest
(e.g., tubidity plumes, macrophyte beds) were not adequately documented for
purposes of this project.  Some parameters of particular interest to us
(e.g., total suspended solids, volatile suspended solids)  were not measured
by the NES.

LANDSAT MSS—

    The LANDSAT multispectral  scanner was not designed  specifically with
lakes in mind.   It  is, both spectrally  and spatially speaking, a low-
resolution  sensor.  While  its  gain can  be increased  in  the GRN and RED bands,
this project was restricted to  the normal gain  settings.   The  "blocky"
appearance  often evident along  the land-water  interface can be disconserting
to the  neophyte user  of LANDSAT  imagery.  Even  more  distracting, as well as
detrimental, is the  "sixth  line"  banding or  striping so apparent in MSS


                                      169

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imagery of water bodies.  Although the trained eye can overlook the striping,
it is distracting.  More importantly, it represents data values that increase
the variance, thereby adding to the uncertainty of satellite-derived trophic
indicator estimates and lake classification products (e.g., thematic
photomaps).  Attempts to destrip MSS data for water bodies have only been
moderately successful.

Multivariate Trophic Indices—

    In Section 6 the use of principal components analysis was demonstrated as
a means of developing two multivariate trophic state indices (i.e., PC1F5,
PC1Y5).  The concept has been used previously to rank lakes (e.g., Boland
1976, Brezonik and Shannon 1971, Sheldon 1972).  We suggest that a word of
caution is in order when examining the resultant ordinations of Illinois
lakes.  Many Illinois water bodies are turbid primarily because of inorganic
suspended solids that drastically reduce light levels and affect algal and
macrophyte productivity.  Still other Illinois lakes have turbidity problems
caused by algae.  It may be more proper to segregate the water bodies into
two or more basic groups and then apply the principal components analysis or
some other ordination technique.  This is one area that should be explored
further.

Illinois Lakes Data Base--

    Prior to the commencement of this project, the IEPA had assembled very
little information on the chemical and biological quality of the State's
lakes.  With the exception of some scattered reports that were available from
other State or Federal  agencies on specific lakes, no comprehensive inventory
of lake data existed.   This information was required to process the MSS tapes
and to interpret and evaluate the classification results.  The task of
assembling and verifying the necessary data was laborious and took several
months.  Furthermore, quality control and comparability problems arise when
using data from several different sources.

    At the onset of this project, the IEPA had no formal program for the
monitoring and classification of lakes.  While much information was initially
available from numerous individuals within the Agency, it took a substantial
amount of time to consolidate Agency expertise on the condition and nature of
Illinois water bodies.

Model Development—

    The development  of  the regression models was no trivial task.  The
difficulty was caused,  in part, by the nonnormality of the ground truth and
MSS data, the very limited range of DN levels  in the four LANDSAT-1 MSS
bands, and the receipt  of faulty MSS data for  scene 1449-16084.  The models
are specific to the  set of scenes from which they were developed.   It is
unlikely that they will yield satisfactory results if applied to other
LANDSAT scenes.  However, the overall approach is applicable to lakes in
other  geographic areas  and to satellite MSS data collected at other times.
                                      170

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    Whether employing regression analysis or clustering techniques, the  use
of average DN values for each spectral  band for a lake does  not  account  for
the spectral variability for a specific portion of a lake and its  associated
trophic condition.  Thus, lake characterization using average spectral
responses affords, at best, the average lake response but provides no
information about its variability.  This information is revealed through the
analysis of band DN histograms, or by optical  techniques that convert  the
differing DN values into a false-color image.   Information regarding
variability within lakes was not obtained in this study.
                                     171

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                                  APPENDIX
           MEASURED AND ESTIMATED WATER QUALITY DATA FOR SELECTED
                            ILLINOIS WATER BODIES
Table                                                                  Page

  A-l    Unadjusted and adjusted multispectral scanner data for
           Illinois water bodies (October 14-16, 1973) 	    184

  A-2    Trophic indicator mean values for 31 water bodies sampled
           October 16-19, 1973 	    210

  A-3    Trophic indicator annual mean values for 31 water bodies
           sampled three times during 1973 	    212

  A-4    Trophic indicator and multivariate trophic index estimates
           for 145 Illinois lakes based on set three regression
           models 	    214

  A-5    Group and individual lake water quality and ancillary data
           values for selected Illinois water bodies classified by
           complete linkage clustering on four spectral attributes
           (GRN, RED, IR1, IR2) 	    220
                                      183

-------
        TABLE A-l.  UNADJUSTED AND ADJUSTED MULTISPECTRAL SCANNER DATA FOR ILLINOIS WATER BODIES
                    (OCTOBER 14, 15, and 16, 1973)*


Name of Water Body
Anderson




NES LANDSAT LANDSAT
Serial STORET Scene Scene Area
Number Number Date Number** Pixels (ha)
34 10-15-73 1449-16084 969 620

10-16-73 1450-16142 944 603


LANDSAT MSS Mean DN
Value and (Deviation)
URN RED
41.89 30.16
(3.56) (3.19)
42.19 30.63
(2.19) (1.81)
+43.26 +30.22
IR1
22.63
(5.66)
23.49
(3.52)
+22.08
IR2
9.02
(5.02)
9.09
(4.96)
+9.30
Apple Canyon
Argyle
Bakers
Bangs
Bath
144
157
 19
 56
166
10-16-73  1450-16140   240    153
10-16-73  1450-16142    49     31
10-14-73  1448-16023    78
10-14-73  1448-16023   191    122



10-15-73  1449-16084    97     62

10-16-73  1450-16142    73     47
                                    33.22  18.82
                                    (3.15) (4.11)
                                   +36.72 +21.03

                                    39.16  26.36
                                    (1.82) (1.95)
                                   +41.05 +26.90
                    15.95   10.81
                    (6.38)  (8.13)
                   +17.44  +10.39

                    20.32   14.20
                    (5.51)  (7.99)
                   +20.13  +12.54
50   46.42  31.56   29.03   11.84
     (2.39) (2.12)  (3.04)  (5.09)
    +45.51 +30.92  +28.48  +12.13
                                    37.36  21.40
                                    (2.17)  (2.78)
                                   +36.74 +20.60

                                    40.33  29.74
                                    (3.86)  (4.06)
                                    42.10  31.68
                                    (2.41)  (2.73)
                                   +43.20 +31.04
                    14.83    6.20
                    (5.32)  (6.29)
                   +15.03   +7.15
                    28.19
                    (6.92)
                    27.71
                    (3.45)
                   +24.68
                                                           16.02
                                                           (7.35)
                                                           14.78
                                                           (5.99)
                                                          +12.91
                                                                                             (continued)

-------
                                            TABLE  A-l.   (continued)
00
en

Name of Water
Biq
U 1 VJ



Rid
L* 1 M



NES LANDSAT
Serial STORE! Scene
Body Number Number Date
134 10-15-73

10-16-73


176 10-15-73

10-16-73


LANDSAT
Scene
Number** Pixels
1449-16084 149

1450-16142 127


1449-16084 117

1450-16142 106


LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) GRN
95 39.
(3.
81 39.
(2.
+41.
75 40.
(3.
68 42.
(2.
+43.
66
56)
79
13)
51
66
95)
30
51)
34
RED
26
(3
28
(2
+28
29
(3
31
(2
+31
.65
.60)
.11
.23)
.26
.80
.44)
.77
.84)
.11
IR1
25
(9
22
(6
+21
26
(8
25
(4
+23
.18
.85)
.48
.08)
.46
.55
.80)
.03
.63)
.03
IR2
13.
(8.
11.
(6.
+11.
11.
(6.
11.
(6.
+10.
56
11)
77
81)
00
70
53)
21
27)
65
     Bloomington


     Bracken



     Calumet



     Canton
 71     1703  10-15-73  1449-16084   374    238


145           10-16-73  1450-16142    83     53



 18           10-14-73  1448-16023   631    403



 36           10-15-73  1449-16084   151     97

             10-16-73  1450-16141   128     82
 38.87  27.00   24.16   11.78
 (3.65) (3.94) (11.50)  (8.42)
 35.53  19.84
 (2.05) (2.74)
+38.40 +21.82

 52.22  41.40
 (3.59) (3.95)
+51.13 +40.92

 41.28  28.19
 (4.02) (3.83)
 42.40  30.48
 (2.74) (3.57)
+43.41 +30.10
 18.28   12.40
 (5.64)  (7.75)
+18.87  +11.40

 25.44   10.41
 (4.78)  (6.48)
+25.03  +10.87
 26.95
(12.09)
 21.39
 (4.95)
+20.79
 12.34
 (7.23)
 10.75
 (7.25)
+10.35
                                                                                                   (continued)

-------
                                            TABLE A-l.   (continued)
CO
CTi
NES LANDSAT LANDSAT LANDSAT MSS Mean DN
Serial STORE! Scene Scene Area Value and (Deviation)
Name of Water Body Number Number Date Number** Pixels (ha) GRN RED IR1 IR2
Carbondale




Carlyle


Catherine


Cattail


Cedar




38 10-14-73 1448-16035 45 29 47.
(2.
+46.
10-15-73 1449-16093 42 27 45.
(2.
14 1706 10-14-73 1448-16032 15,435 9,864 46.
(2.
+45.
58 10-14-73 1448-16023 95 61 35.
(1.
+35.
125 10-16-73 1450-16140 30 19 36.
(2.
+39.
39 10-14-73 1448-16035 113 72 43.
(4.
+42.
10-15-73 1449-16093 121 77 40.
(4.
22
38)
28
09
42)
30
36)
39
77
90)
20
83
22)
35
59
54)
77
28
18)
34.
(4.
+34.
34.
(3.
31.
(2.
+31.
19.
(1.
+18.
26.
(2.
+26.
32.
(7.
+31.
28.
(6.
62
89)
03
19
77)
66
98)
02
65
84)
82
36
44)
90
15
35)
52
87
36)
28.
(6.
+28.
27.
(5.
18.
(5.
+18.
14.
(5.
+15.
26.
(2.
+23.
23.
(7.
+23.
21.
(7.
75
09)
22
90
58)
18
08)
20
96
18)
15
29
79)
80
66
33)
40
76
03)
13.
(7.
+13.
13.
(5.
6.
(5.
+6.
6.
(5.
+7.
19.
(5.
+16.
13.
(7.
+13.
12.
(7.
79
71)
85
33
58)
01
22)
99
28
93)
22
69
87)
02
11
35)
25
85
45)
    Cedar
55
1759  10-14-73  1448-16023   200
128   34.68  19.65
      (2.71) (4.17)
     +34.14 +18.82
 13.58    6.86
 (6.99)  (7.42)
+13.85   +7.74
                                                                                                  (continued)

-------
                                            TABLE A-l.  (continued)
     Name of Water Body
         NES
Serial   STORE!
Number  Number
         LANDSAT   LANDSAT
         Scene     Scene             Area
         Date      Number**  Pixels  (ha)
      LANDSAT MSS Mean DN
    Value and (Deviation)
   GRN    RED     IR1     IR2
00
     Centralia
     Chain, Ingram,
      Sangamon, Stafford,
      Stewart, Snicarte
     Channel
     Charleston
     Chautauqua
     Clear
   79
   83
   59
  16
   87
10-14-73  1448-16032   144     92



10-15-73  1449-16084   427    273

10-16-73  1450-16142   467


10-14-73  1448-16023   221    141
                                           36.47  21.86   17.86   11.38
                                           (2.37) (2.98)  (6.12)  (7.84)
                                          +35.87 +21.06  +17.90  +11.72
                                           40.27  29.10
                                           (3.28)  (2.84)
                                     298   41.21  30.74
                                          +42.55 +30.30
                 25.50   11.59
                 (6.72)  (6.01)
                 25.88   12.03
                +23.55  +11.16
1708  10-14-73  1448-16032   189    121
  37.51  21.85   16.72    6.72
 (1.74) (2.71)  (5.13)  (6.49)
 +36.88 +21.05  +10.82   +7.61

 42.39  30.65   22.51    9.91
 (2.53) (2.34)  (3.51)  (6.02)
+41.61 +30.00  +22.31  +10.43
       10-15-73  1449-16084  1,610  1,030  42.66  32.41   26.91   11.78
                                          (3.99) (4.50)  (4.92)  (3.73)
       10-16-73  1450-16142  1,604  1,025  42.30  32.09   26.17   11.18
                                           (2.75)  (3.54)   (2.29)  (3.27)
                                          +43.34 +31.36  +23.73  +10.63
  86
10-15-73  1449-16084   977    625

10-16-73  1450-16142   968    619
                                   41.10  30.26
                                   (3.35) (2.55)
                                   41.08  30.46
                                   (2.12) (1.91)
                                  +42.45 +30.09
                25.67
                (5.50)
                25.40
                (2.94)
               +23.26
                                                                 11.71
                                                                 (4.89)
                                                                 11.30
                                                                 (4.46)
                                                                +10.70
                                                                                                   (continued)

-------
                                            TABLE A-l.  (continued)
00
00
Name of Water Body
Coal City Recreation
Club



Commonwealth Edison-
Dresden Nuclear



Countryside


Crab Orchard


Crane




NES LANDSAT
Serial STORET Scene
Number Number Date
138 10-14-73


10-15-73

137 10-14-73


10-15-73

148 10-14-73


127 1712 10-14-73


85 10-15-73

10-16-73


LANDSAT
Scene
Number** Pixels
1448-16023 53


1449-16082 51

1448-16023 720


1449-16082 720

1448-16023 80


1448-16035 4,198


1449-16084 1,212

1450-16142 1,589


LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) GRN RED IR1 IR2
34 48
(5
+47
33 48
(5
460 41
(3
+40
460 41
(3
51 38
(1
+37
2,683 39
(2
+38
776 43
(4
1,015 44
(3
+45
.03
.31)
.07
.43
.35)
.26
.40)
.51
.31
.49)
.16
.34)
.51
.15
.29)
.47
.71
.90)
.83
.84)
.19
28
(4
+28
28
(4
29
(3
+28
29
(3
22
(1
+21
24
(2
+23
34
(6
35
(5
+34
.90
.38)
.22
.41
.21)
.34
.42)
.66
.56
.56)
.34
.40)
.55
.32
.67)
.56
.11
.41)
.54
.43)
.04
22
(6
+22
22
(6
17
(4
+17
17
(4
18
(4
+18
17
(5
+17
27
(6
27
(3
+24
.90
.48)
.68
.56
.13)
.32
.94)
.39
.53
.93)
.15
.53)
.18
.36
.33)
.43
.69
.39)
.79
.41)
.73
16
(7
+16
16
(7
6
(5
+7
7
(5
8
(6
+9
6
(6
+7
11
(4
12
(4
+11
.73
.83)
.44
.54
.29)
.71
.31)
.60
.18
.19)
.84
.99)
.48
.76
.33)
.65
.63
.47)
.34
.16)
.36
     Crooked
149
10-14-73  1448-16023
84     54   45.82  26.64   24.54    9.74
            (1.80) (1.62)  (4.15)   (5.75)
           +44.93 +25.92  +24.23  +10.28
                                                                                                   (continued)

-------
                                             TABLE A-l.   (continued)
00
IO

NES LANDSAT LANDSAT
Serial STORET Scene Scene
Name of Water Body Number Number Date Number** Pixels
Crystal

Dawson

Decatur




Deep


DePue




68 10-15-73 1449-16082 146

70 10-15-73 1449-16084 105

73 1714 10-14-73 1448-16032 1,778


10-15-73 1449-16084 1,862

150 10-14-73 1448-16023 136


3 1752 10-15-73 1449-16082 360

10-16-73 1450-16140 373


LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) GRN RED IR1 IR2
93 36
(1
67 37
(3
1,136 39
(2
+39
1,192 38
(3
87 36
(1
+36
230 41
(2
238 39
(2
+41
.69
.98)
.47
.23)
.7-8
.33)
.08
.38
.62)
.80
.49)
.19
.06
.51)
.38
.53)
.21
20
(2
25
(4
27
(2
+27
27
(3
19
(2
+19
29
(2
29
(2
+29
.78
.90)
.26
.09)
.83
.35)
.13
.30
.28)
.86
.11)
.03
.52
.18)
.80
.37)
.57
15
(5
27
(13
18
(4
+18
21
(8
12
(4
+13
22
(4
23
(3
+22
.21
.93)
.70
.88)
.60
.59)
.60
.74
.45)
.85
.98)
.16
.53
.30)
.90
.38)
.33
8
(6
15
(13
7
(6
+8
9
(6
6
(6
+7
10
(6
11
(5
+11
.02
.39)
.18
.73)
.49
.03)
.29
.84
.68)
.03
.00)
.00
.59
.23)
.84
.61)
.04
     Devil's Kitchen
128
10-14-73  1448-16035   370
236   34.07  17.48
      (1.81) (2.07)
     +33.55 +16.61
 15.30    9.89
 (6.46)  (7.85)
+15.48  +10.41
                                                                                                    (continued)

-------
TABLE A-l.  (continued)

NES LANDSAT LANDSAT LANDSAT MSS Mean DN
Serial STORET Scene Scene Area Value and (Deviation)
Name of Water Body Number Number Date Number** Pixels (ha) GRN RED IR1 IR2
Diamond


DuQuoin




Dutchman


East Loon


Evergreen

Fourth


Fox


57 10-14-73 1448-16023 95 61 39.
(2.
+38.
98 10-14-73 1448-16035 86 55 34.
(3.
+34.
10-15-73 1449-16093 81 52 32.
(2.
49 10-14-73 1448-16035 26 17 37.
(2.
+37.
53 1757 10-14-73 1448-16023 105 67 35.
(1.
+34.
72 10-15-73 1449-16084 466 298 36.
(3.
151 10-14-73 1448-16023 200 128 42.
(2.
+41.
60 1755 10-14-73 1448-16023 1,159 741 39.
(2.
+39.
03
00)
35
59
28)
05
97
61)
80
45)
16
27
74)
71
88
70)
37
14)
59
92
27)
22
22.
(2.
+21.
20.
(4.
+20.
19.
(3.
21.
(2.
+20.
20.
(2.
+20.
23.
(5.
30.
(1.
+29.
26.
(1.
+25.
75
39)
97
81
05)
00
76
87)
42
51)
62
85
32)
04
40
07)
04
57)
38
67
98)
95
15.
(5.
+15.
18.
(7.
+18.
17.
(6.
18.
(6.
+18.
15.
(5.
+16.
21.
(11.
21.
(3.
+21.
17.
(3.
+18.
63
45)
79
53
41)
54
55
59)
42
95)
43
88
91)
03
80
99)
63
89)
47
99
85)
02
6.
(6.
+7.
10.
(8.
+11.
10.
(7.
11.
(8.
+11.
8.
(6.
+9.
10.
(7.
8.
(6.
+9.
6.
(5.
+7.
74
86)
63
97
42)
36
16
52)
65
30)
96
53
84)
21
77
45)
53
27)
21
09
06)
06
                                                      (continued)

-------
                                       TABLE A-l.  (continued)
Name of Water Body
         NES
Serial  STORE!
Number  Number
LANDSAT   LANDSAT
 Scene     Scene             Area
 Date      Number**  Pixels  (ha)
  LANDSAT MSS Mean DN
 Value and (Deviation)
GRN    RED     IR1     IR2
Fyre                    170
Gages                   152
George                  108
Glen 0. Jones           110
Goose  (Sparland          82
 Conservation Area)

Goose                   101
               10-16-73  1450-16140    60     38



               10-14-73  1448-16023    83     53



               10-16-73  1450-16140    89     57



               10-14-73  1448-16035    61     39



               10-15-73  1449-16084   604    387


               10-15-73  1449-16082  1,088   696

               10-16-73  1450-16140  1,160   741
                                   32.94  19.18
                                   (2.40) (3.25)
                                  +36.52 +21.31

                                   36.16  20.38
                                   (1.76) (2.12)
                                  +35.57 +19.56
              17.84   11.76
              (6.80)  (8.19)
             +18.60  +10.99

              14.01    6.28
              (5.09)  (5.43)
             +14.25   +7.22
                                   35.43  19.55   15.87   10.62
                                   (1.68) (2.18)  (6.00)  (8.21)
                                  +38.33 +21.60  +17.39  +10.27
                                   36.91  19.86
                                   (2.53) (3.16)
                                  +36.30 +19.03
              15.32    9.02
              (6.15)  (7.17)
             +15.50   +9.64
                                   42.58  34.18   27.51
                                   (3.55) (4.15)  (5.09)
                                   42.67  31.37
                                   (1.96) (1.73)
                                   40.60  31.93
                                   (2.00) (1.77)
                                  +42.10 +31.22
              24.88
              (2.82)
              28.04
              (2.03)
             +24.88
 12.80
 (4.53)

 11.06
 (4.03)
 16.56
 (3.63)
+14.04
                                                                                             (continued)

-------
                                            TABLE A-l.   (continued)
vo
ro
Name of Water Body
Goose (Village Club)
Grass
Greenville New City
(Governor Bond)
Griswold
Harrisburg
Highland (Old Taylor
NES LANDSAT
Serial STORET Scene
Number Number Date
139 10-14-73
10-15-73
61 1756 10-14-73
2 10-14-73
158 10-15-73
111 10-14-73
153 10-14-73
LANDSAT
Scene
Number**
1448-16023
1449-16082
1448-16023
1448-16032
1449-16082
1448-16035
1448-16023
Pixels
116
117
1,025
482
30
94
65
Area
(ha)
74
75
655
308
19
60
42
LANDSAT MSS Mean DN
Value and (Deviation)
GRN RED IR1
IR2
45.05 31.40 24.10 17.05
(6.79) (7.63) (7.98) (8.10)
+44.18 +30.76 +23.81 +16.73
45.01 31.92 25.13 17.97
(6.72) (8.03) (8.14) (7.39)
37.61 25.95 17.38
(1.69) (2.20) (4.11)
+36.98 +25.22 +17.45
38.52 24.90 18.43
(2.41) (2.76) (5.73)
+37.86 +24.15 +18.44
36.59 22.49 19.66
(2.39) (2.45) (5.27)
36.08 22.34 18.10
(3.63) (4.09) (7.12)
+35.50 +21.55 +18.13
33.52 17.87 12.61
(1.58) (1.60) (4.65)
+33.02 +17.01 +12.93
7.00
(5.79)
+7.86
8.90
(7.22)
+9.54
11.69
(6.09)
10.64
(7.64)
+11.07
5.80
(5.89)
+6.80
     Holiday
51
1754  10-15-73  1449-16082   186
119   35.36  22.09  17.15     8.65
      (1.98) (2.14) (4.97)   (6.19)
                                                                                                   (continued)

-------
                                       TABLE A-l.   (continued)

NES LANDSAT
Serial STORET Scene
Name of Water Body Number Number Date
Horseshoe 1

Jack, Swan, Grass 165




Keithsburg National 92
Wildlife Refuge

Kinkaid 40




Kinneman 168
10-15-73

10-15-73

10-16-73


10-16-73


10-14-73


10-15-73

10-14-73
LANDSAT
Scene
Number** Pixels
1449-16093 262

1449-16084 927

1450-16142 859


1450-16142 126


1448-16035 1,338


1449-16093 1,371

1448-16035 36
LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) GRN RED IR1 IR2
168 38.
(5.
593 39.
(3.
549 39.
(1.
+41.
81 36.
(1.
+39.
855 37.
(4.
+36.
876 42.
(4.
23 50.
72
13)
32
22)
49
97)
29
85
77)
37
43
71)
80
03
20)
08
25
(6
27
(2
28
(1
+28
25
(1
+26
22
(6
+21
21
(5
33
.28
.47)
.39
.41)
.57
.86)
.62
.34
.62)
.10
.52
.75)
.73
.13
.29)
.44
23.
(8.
23.
(6.
23.
(3.
+21.
25.
(4.
+23.
17.
(7.
+17.
16.
(7.
30.
12
29)
62
90)
27
63)
94
76
61)
48
22
82)
30
07
27)
44
12.
(8.
10.
(5.
9.
(4.
+9.
19.
(6.
+16.
9.
(7.
+9.
8.
(7.
20.
57
39)
56
89)
99
93)
87
80
16)
09
26
71)
85
76
77)
33
Lake of Egypt
132
10-14-73  1448-16035  1,186   758
 (4.69) (5.00)
+49.05 +32.83

 39.75  23.72
 (4.67) (4.66)
+39.05 +22.95
 (5.87)  (4.93)
+29.55  +19.62

 17.03    9.41
 (6.48)  (7.54)
+17.12   +9.99
                                                                                             (continued)

-------
                                            TABLE A-l.   (continued)
ID
NES LANDSAT LANDSAT
LANDSAT MSS Mean DN
Serial STORE! Scene Scene Area Value and (Deviation)
Name of Water Body Number Number Date Number** Pixels (ha) GRN RED IR1 IR2
Lake of the Woods 115




LaRue-Pine Hills 121
Ecological area

Lily 136




10-15-73 1449-16084 65 42 40.
(3.
10-16-73 1450-16142 58 37 40.
(2.
+41.
10-14-73 1448-16035 18 12 37.
(2.
+37.
10-15-73 1449-16084 102 65 43.
(4.
10-16-73 1450-16142 85 54 44.
(2.
+44.
65
99)
44
90)
99
94
37)
30
84
12)
32
08)
81
29
(3
29
(2
+29
24
(3
+23
34
(4
36
(2
+34
.42
.97)
.96
.70)
.70
.05
.66)
.29
.94
.89)
.69
.99)
.93
29.
(6.
27.
(3.
+24.
29.
(4.
+28.
36.
(10.
30.
(3.
+26.
51
84)
75
63)
70
22
05)
66
76
50)
17
95)
19
15.
(6.
13.
(5.
+12.
23.
(5.
+22.
17.
(6.
16.
(5.
+14.
85
52)
77
29)
27
27
02)
21
62
31)
69
71)
12
     Lincoln Trail  State      13
      Park
     Little Grassy           119
     Little Swan             185
10-14-73  1448-16032    73     47
10-14-73  1448-16035   522    334
10-16-73  1450-16142   151     97
 34.34  17.72
 (2.54) (2.56)
+33.81 +16.86

 35.30  18.56
 (2.22) (2.45)
+34.74 +17.71

 40.97  31.39
 (1.34) (1.39)
+42.37 +30.31
 15.60   10.30
 (6.01)  (6.35)
+15.76  +10.77

 14.27    8.39
 (6.53)  (7.72)
+14.50   +9.09

 23.14   12.13
 (3.47)  (4.59)
+21.86  +11.23
                                                                                                   (continued)

-------
                                            TABLE A-l.   (continued)
C7I
NES LANDSAT
Serial STORE! Scene
Name of Water Body Number Number Date
Liverpool




Long


Long




Lower Smith




88 10-15-73

10-16-73


52 1725 10-14-73


177 10-15-73

10-16-73


181 10-15-73

10-16-73


LANDSAT
Scene
Number** Pixels
1449-16084 36

1450-16142 30


1448-16023 242


1449-16084 77

1450-16142 68


1449-16084 79

1450-16142 60


LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) GRN RED IR1 IR2
23 42
(3
20 43
(2
+43
155 36
(1
+35
49 43
(5
44 44
(3
+44
51 40
(3
38 42
(2
+43
.17
.93)
.03
.32)
.87
.58
.76)
.98
.12
.08)
.23
.77)
.75
.91
.58)
.39
.65)
.41
30
(4
33
(2
+32
23
(1
+22
32
(5
34
(5
+32
29
(3
32
(2
+31
.77
.13)
.83
.08)
.71
.53
.71)
.76
.66
.83)
.11
.16)
.93
.77
.36)
.18
.67)
.43
34
(7
29
(3
+25
16
(4
+16
30
(9
27
(5
+24
30
(10
25
(3
+23
.57
.57)
.23
.86)
.62
.40
.44)
.52
.70
.20)
.80
.42)
.73
.04
.33)
.26
.52)
.17
19.
(7.
16.
(5.
+14.
6.
(5.
+7.
14.
(7.
13.
(6.
+12.
15.
(7.
14.
(6.
+12.
86
41)
96
76)
29
42
82)
35
51
28)
61
52)
17
24
59)
69
85)
85
     Lyerla-Autumnal
      Flooding  Ponds
120
10-14-73  1448-16035   345
221   42.31  27.46
      (3.68) (3.30)
     +41.53 +26.75
 24.34   13.71
 (7.04)  (8.03)
+24.04  +13.78
                                                                                                  (continued)

-------
                                             TABLE A-l.  (continued)
CTv

Name of Water Body
Marie


Marion


Marshall County Pu-
lic Hunting and
Fishing Area


Matanzas




Mattoon


McCullom

NES LANDSAT
Serial STORE! Scene
Number Number Date
62 1727 10-14-73


129 10-14-73


81 10-15-73

10-16-73


89 10-15-73

10-16-73


24 10-14-73


159 10-15-73

LANDSAT
Scene
Number** Pixels
1448-16023 347


1448-16035 81


1449-16084 1,131

1450-16142 1,138


1449-16084 242

1450-16142 236


1448-16032 611


1449-16082 168

LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) GRN RED IR1 IR2
222 39.
(2.
+38.
52 34.
(2.
+34.
724 39.
(3.
729 38.
(1.
+40.
155 41.
(3.
151 42.
(2.
+43.
391 42.
(2.
+41.
107 37.
(2.
18
19)
50
86
05)
32
09
22)
95
86)
90
79
45)
08
07)
18
07
83)
30
08
02)
25
(2
+24
20
(2
+19
27
(2
28
(2
+28
31
(2
31
(1
+31
28
(2
+27
21
(2
.04
.11)
.30
.24
.27)
.42
.38
.60)
.87
.07)
.85
.60
.60)
.85
.80)
.17
.13
.69)
.43
.39
.35)
19
(4
+19
18
(6
+18
23
(5
24
(2
+22
24
(5
25
(3
+23
18
(6
+18
17
(5
.07
.79)
.05
.59
.52)
.59
.48
.70)
.95
.81)
.98
.57
.54)
.08
.14)
.06
.31
.16)
.33
.40
.69)
7.
(6.
+8.
10.
(7.
+11.
10.
(5.
11.
(4.
+11.
11.
(6.
11.
(5.
+10.
8.
(7.
+9.
10.
(7.
76
23)
53
92
37)
32
51
09)
94
54)
11
43
13)
12
33)
59
73
57)
39
38
24)
                                                                                                    (continued)

-------
                                       TABLE A-l.  (continued)

NES LANDSAT
Serial STORE! Scene
Name of Water Body Number Number Date
McGinnis (Orland) 20




Meredosia 10




Mesa 184


Moscow 164




10-14-73


10-15-73

10-15-73

10-16-73


10-14-73


10-15-73

10-16-73


LANDSAT
Scene
Number** Pixels
1448-16023 179


1449-16082 160

1449-16084 1,100

1450-16142 965


1448-16032 56


1449-16084 164

1450-16142 148


LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) CRN RED IR1 IR2
114 37.
(2.
+37.
102 38.
(1.
704 46.
(5.
617 46.
(4.
+46.
36 37.
(2.
+36.
106 40.
(3.
95 40.
(2.
+42.
99
42)
35
35
50)
36
37)
85
23)
66
26
04)
64
09
53)
94
18)
35
23.71
(2.
+22.
24.
(1.
38.
(7.
39.
(6.
+37.
20.
(2.
+19.
28.
(3.
29.
(1.
+29.
42)
94
04
46)
49
29)
52
45)
14
80
22)
99
15
32)
72
82)
51
27.59
(4.04)
+27.12
28.
(2.
28.
(6.
28.
(4.
+25.
15.
(5.
+15.
25.
(7.
25.
(3.
+23.
03
52)
97
26)
33
60)
06
46
82)
63
85
21)
06
64)
05
13.36
(4.88)
+13.47
12.
(4.
12.
(6.
12.
(5.
+11.
8.
(6.
+9.
12.
(7.
12.
(5.
+11.
89
05)
81
15)
01
25)
15
39
83)
09
95
11)
13
45)
23
Moses
28
10-14-73  1448-16035    75
48   33.86  19.55   18.06   11.90
     (2.55) (3.11)  (6.95)  (8.38)
    +33.35 +18.72  +18.09  +12.18
                                                                                             (continued)

-------
                                            TABLE A-l.  (continued)
00

Name of Water Body
Mound




Murphysboro




New Pittsfield
NES LANDSAT
Serial STORET Scene
Number Number Date
163 10-15-73

10-16-73


37 10-14-73


10-15-73

100 10-16-73
LANDSAT
Scene
Number
1449-16084

1450-16142


1448-16035


1449-16093

1450-16142

Pixels
353

329


74


85

113
Area
(ha)
226

210


47


54

72
LANDSAT MSS Mean DN
Value and (Deviation)
CRN
36.
(3.
36.
(1.
+39.
37.
(1.
+36.
35.
(1.
45.
85
04)
46
52)
08
29
60)
67
04
81)
65
RED
24.
(2.
24.
(1.
+25.
21.
(2.
+20.
19.
(1.
36.
57
91)
90
80)
76
56
02)
76
76
93)
75
IR1
24.
(9.
21.
(3.
+20.
16.
(4.
+16.
17.
(6.
25.
13
27)
47
74)
84
21
80)
34
32
71)
29
IR2
11.76
(6.70)
10.75
(5.82)
+10.35
9.04
(6.24)
+9.66
11.18
(8.53)
11.67
     Nipper sink
     Old Ben Mine
     Olney East Fork
 63
            10-14-73  1448-16023   310
32    1765  10-14-73  1448-16035
                                     44
106
            10-14-73  1448-16032   448
      (3.39) (5.01)
     +45.78 +34.98

198   38.24  25.94
      (2.17) (2.57)
     +37.59 +25.21

 28   37.97  24.45
      (3,06) (2.82)
     +37.33 +23.70

286   39.25  22.69
      (3.37) (3.65)
     +38.57 +21.91
 (4.54)  (6.00)
+23.19  +10.94

 17.51    6.61
 (3.95)  (5.13)
+17.57   +7.52

 20.59   11.63
 (6.99)  (6.89)
+20.49  +11.94

 17.28    9.47
 (6.97)  (7.69)
+17.35  +10.04
                                                                                                   (continued)

-------
                                            TABLE A-l.  (continued)
VO

NES LANDSAT LANDSAT LANDSAT MSS Mean DN
Serial STORE! Scene Scene Area Value and (Deviation)
Name of Water Body Number Number Date Number** Pixels (ha) 6RN
Olney New 107


Open Pond (Marshy) 174


Otter 167




10-14-73 1448-16032 68 44 37.
(2.
+36.
10-14-73 1448-16035 152 97 40.
(4.
+40.
10-15-73 1449-16084 117 75 36.
(3.
10-16-73 1450-16142 93 59 36.
(2.
+39.
54
80)
91
94
79)
20
69
43)
92
35)
42
RED
22
(3
+21
27
(7
+26
24
(3
25
(2
+26
.38
.01)
.59
.26
.72)
.55
.22
.35)
.43
.89)
.17
IR1
20.
(7.
+19.
24.
(8.
+24.
26.
(8.
23.
(4.
+21.
01
27)
94
74
07)
42
36
43)
08
73)
83
IR2
12.
(7.
+13.
17.
(7.
+17.
16.
(7.
15.
(7.
+13.
99
36)
14
62
67)
23
45
39)
23
02)
19
     Pana
     Paradise
     Paris Twin
113
 15
 25
10-14-73  1448-16032   118     75
10-14-73  1448-16032    88     56
10-14-73  1448-16032   111     71
 41.68  28.06
 (5.47) (7.81)
+40.92 +27.36

 40.70  27.95
 (1.85) (1.44)
+39.97 +27.25

 34.98  20.78
 (2.71) (3.01)
+34.43 +19.97
 20.73   12.42
 (7.68)  (7.72)
+20.62  +12.64

 19.59    9.10
 (5.33)  (7.43)
+19.54   +9.71

 18.35   12.22
 (6.61)  (7.27)
+18.37  +12.47
                                                                                                  (continued)

-------
                                            TABLE A-l.   (continued)
o
o

Name of Water Body
Pekin


k

Petersburg

Petite


Pierce




Pinckneyville




Pistakee


NES LANDSAT
Serial STORET Scene
Number Number Date
116 10-15-73

10-16-78


169 10-15-73

64 10-14-73


130 10-15-73

10-16-73


99 10-14-73


10-15-73

65 1733 10-14-73


LANDSAT
Scene
Number** Pixels
1449-16084 97

1450-16142 58


1449-16084 89

1448-16023 103


1449-16082 91

1450-16140 94


1448-16035 77


1440-16093 77

1448-16023 1,067


LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) GRN RED IR1 IR2
62 41.27 30.62 29.44
(4.14) (4.22) (5.76)
37 42.12 32.32 27.18
(2.82) (2.79) (3.97)
+43.21 +31.53 +24.35
57 37.06 22.38 25.47
(5.63) (8.23) (15.49)
66 39.10 25.50 18.30
(1.76) (1.80) (4.36)
+38.42 +24.76 +18.32
58 37.74 21.96 17.86
(2.04) (2.27) (5.59)
60 33.07 19.39 15.62
(2.06) (2.18) (5.21)
+36.61 +21.47 +17.23
49 41.50 26.28 18.48
(3.06) (2.93) (5.06)
+40.75 +25.56 +18.49
49 39.16 24.51 18.40
(3.00) (2.93) (5.56)
682 37.73 23.79 16.88
(1.72) (2.08) (4.50)
+37.08 +23.02 +16.97
17.00
(6.64)
14.43
(5.79)
+12.69
12.40
(7.55)
7.81
(6.62)
+8.57
9.84
(6.83)
8.14
(7.20)
+8.70
8.47
(7.09)
+9.16
8.87
(7.02)
6.55
(5.89)
+7.46
                                                                                                  (continued)

-------
                                            TABLE A-l.   (continued)
ro
o

Name of Water Body
Powerton Cooling




Quiver




Raccoon


Rend


Rice




NES LANDSAT
Serial STORET Scene
Number Number Date
182 10-15-73

10-16-73


90 10-15-73

10-16-73


80 1762 10-14-73


29 1735 10-14-73


35 10-15-73

10-16-73


LANDSAT
Scene
Number**
1449-16084

1450-16142


1449-16084

1450-16142


1448-16032


1448-16035


1449-16084

1450-16142


LANDSAT MSS Mean DN
Area Value and (Deviation)
Pixels (ha) GRN RED IR1 IR2
893 572 36
(3
928 593 36
(2
+38
216 138 40
(3
210 134 39
(2
+41
366 234 45
(3
+44
9,765 6,242 37
(3
+37
976 625 37
(3
947 605 37
(1
+39
.89
.81)
.33
.34)
.99
.13
.56)
.90
.61)
.59
.23
.00)
.36
.71
.20)
.08
.91
.18)
.00
.65)
.48
22
(4
22
(2
+23
30
(4
30
(3
+30
31
(3
+31
24
(3
+23
24
(2
25
(1
+26
.33
.36)
.54
.90)
.92
.59
.23)
.43
.15)
.06
.66
.81)
.02
.52
.86)
.77
.90
.62)
.28
.85)
.06
16
(7
16
(3
+17
26
(6
22
(5
+21
21
(4
+20
15
(5
+15
21
(6
20
(3
+20
.63
.54)
.04
.78)
.49
.47
.11)
.59
.24)
.53
.04
.47)
.91
.18
.68)
.36
.96
.77)
.70
.74)
.36
6
(4
5
(4
+7
13
(7
11
(6
+10
8
(5
+9
6
(6
+7
9
(6
8
(5
+8
.94
.75)
.90
.54)
.28
.84
.33)
.29
.96)
.70
.29
.89)
.00
.39
.27)
.32
.98
.03)
.68
.62)
.99
                                                                                                   (continued)

-------
                                            TABLE A-l.  (continued)
ro
o
ro



Name of Water Body
Round


Saganashkee




Sahara Coal Company


NES LANDSAT
Serial STORET Scene
Number Number Date
66 10-14-73


21 10-14-73


10-15-73

175 10-14-73


LANDSAT
Scene
Number**
1448-16023


1448-16023


1449-16082

1448-16035


LANDSAT MSS Mean DN

Pixels
147


229


262

153


Area
(ha)
94


146


167

98


Value and (Deviation)
GRN
37
(1
+36
36
(1
+35
37
(1
49
(3
+48
.21
.57)
.59
.34
.48)
.75
.27
.52)
.09
.16)
.10
RED
21
(2
+20
22
(1
+21
23
(2
40
(4
+40
.39
.23)
.59
.27
.94)
.48
.69
.02)
.58
.11)
.09
IR1
13.11
(5.25)
+13.40
17.49
(4.12)
+17.55
19.30
(5.12)
34.35
(4.25)
+33.52
IR2
5
(6
+6
6
(5
+7
9
(6
24
(3
+23
.75
.39)
.76
.97
.73)
.83
.24
.62)
.19
.61)
.03
     St.  Mary's
     Sam Dale State
     Sam Parr State
146
124
 41
10-14-73  1448-16023    65     42
10-14-73  1448-16032   111     71
10-14-73  1448-16032    82     52
 41.72  23.98
 (2.84) (2.47)
+40.96 +23.22

 35.02  20.13
 (2.56) (3.29)
+34.47 +19.31

 36.23  21.18
 (2.43) (2.82)
+35.64 +20.37
 21.86   11.81
 (4.85)  (7.61)
+21.69  +12.10

 16.93    8.91
 (6.58)  (7.28)
+17.02   +9.54

 21.18   14.31
 (6.07)  (7.46)
+21.05  +14.31
                                                                                                  (continued)

-------
TABLE A-l.  (continued)
NES LANDSAT LANDSAT LANDSAT MSS Mean DN
Serial STORE! Scene Scene Area Value and (Deviation)
Name of Water Body Number Number Date Number** Pixels (ha) GRN RED IR1 IR2
Sand 147 10-14-73 1448-16023 61 39 35.
(1.
+35.
Sanganois Conserva- 9 10-15-73 1449-16084 928 594 43.
tion Area (Muscooten, (5.
Sangamon, Treadway) 10-16-73 1450-16142 666 426 45.
(3.
+45.
o Sangchris 11 10-15-73 1449-16084 1,701 1,089 38.
(3.
Sara 26 10-14-73 1448-16032 308 197 35.
(2.
+34.
Sawmill 103 10-15-73 1449-16082 359 230 39.
(1.
Senachwine 104 10-15-73 1449-16082 2,508 1,603 41.
(2.
10-16-73 1450-16140 1,892 1,209 40.
(2.
+41.
85
74)
27
37
68)
11
99)
39
07
83)
18
76)
63
64
86)
87
15)
31
14)
89
19.
(1.
+18.
34.
(8.
36.
(5.
+34.
26.
(6.
19.
(3.
+19.
28.
(1.
30.
(1.
31.
(1.
+30.
59
66)
76
14
25)
60
42)
86
60
02)
89
36)
06
52
65)
45
78)
05
98)
55
13.
(5.
+14.
33.
(7.
29.
(4.
+26.
24.
(12.
16.
(7.
+16.
24.
(3.
21.
(2.
25.
(2.
+23.
85
43)
10
71
47)
89
18)
02
72
26)
48
05)
59
13
32)
78
86)
21
23)
14
6.
(6.
+7.
16.
(6.
15.
(5.
+13.
14.
(9.
10.
(8.
+11.
10.
(4.
7.
(3.
12.
(3.
+11.
39
38)
32
49
44)
22
86)
19
70
51)
92
39)
32
60
24)
99
73)
19
60)
27
                                                      (continued)

-------
                                          TABLE A-l.  (continued)
PO
o

Serial
Name of Water Body Number
Shelbyville 114




Skokie Lagoons 22




Slocum 54


Snyder's Hunting Club 142




South Wilmington 140
Fireman's Beach and
Park


NES LANDSAT
STORE! Scene
Number Date
1739 10-14-73


10-15-73

10-14-73


10-15-73

1758 10-14-73


10-14-73


10-15-73

10-14-73


10-15-73

LANDSAT
Scene
Number**
1448-16032


1449-16084

1448-16023


1449-16082

1448-16023


1448-16035


1449-16093

1448-16023


1449-16082

Pixels
6,796


7,715

122


131

138


27


27

155


158

Area
(ha)
4,343


4,938

80


84

88


17


17

99


101

LANDSAT MSS Mean DN
Value and (Deviation)
6RN RED IR1 IR2
37
(3
+36
36
(4
41
(2
+40
46
(3
40
(1
+39
36
(2
+36
34
(1
47
(3
+46
46
(3
.59
.03)
.96
.76
.07)
.31
.91)
.56
.35
.87)
.71
.85)
.98
.81
.31)
.20
.48
.79)
.02
.42)
.09
.65
.74)
24.
(4.
+23.
24.
(5.
27.
(3.
+27.
31.
(4.
22.
(1.
+21.
23.
(3.
+22.
22.
(2.
28.
(4.
+27.
28.
(4.
24
12)
48
50
19)
86
79)
16
35
02)
68
50)
90
25
3D
48
29
10)
26
90)
57
49
65)
15
(6
+15
19
(11
27
(5
+26
30
(4
26
(2
+26
20
(6
+20
19
(6
20
(7
+20
21
(6
.26
.23)
.44
.37
.03)
.42
.11)
.96
.87
.81)
.47
.84)
.06
.14
.55)
.06
.37
.28)
.87
.11)
.75
.72
.93)
7.10
(7.07)
+7.95
9.60
(7.75)
17.44
(7.41)
+17.07
19.80
(6.37)
9.46
(4.72)
+10.03
14.33
(7.58)
+14.33
13.74
(8.27)
14.56
(7.48)
+14.53
15.11
(7.74)
                                                                                                   (continu ed)

-------
                                            TABLE A-l.  (continued)



Name of Water Body
Spring




NES LANDSAT
Serial STORE! Scene
Number Number Date
4 10-15-73

10-16-73


LANDSAT
Scene
Number**
1449-16082

1450-16140


LANDSAT MSS Mean DN

Pixels
211

214


Area
(ha)
135

137


Value and (Deviation)
GRN
39.
(2.
37.
(1.
+40.
54
18)
93
82)
15
RED
27
(2
27
(2
+28
.96
.31)
.86
.20)
.06
IR1
24
(4
24
(3
+22
.04
.31)
.72
.68)
.84
IR2
12.14
(6.64)
13.64
(5.64)
+12.19
     Spri ng
o    Spring
tn
     Spring
     Spring Arbor
  8
 67
118
143
10-16-73  1450-16140  1,689  1,079
10-16-73  1450-16142   151     97



10-15-73  1449-16084   845    541

10-16-73  1450-16142   790    505



10-14-73  1448-16035    24     15


10-15-73  1449-16093    27     17
 40.43  31.09
 (2.80) (3.31)
+41.98 +30.58

 40.97  31.39
 (2.50) (2.22)
+42.37 +30.81

 37.32  23.74
 (3.30) (3.35)
 37.02  23.95
 (1.99) (2.41)
+39.49 +25.02

 37.45  21.99
 (2.08) (2.27)
+36.82 +21.20
 34.62  19.66
 (1.93) (2.39)
 23.79   10.51
 (3.62)  (5.23)
+22.26  +10.20

 23.14   12.13
 (4.21)  (6.81)
+21.86  +11.23
 21.54
 (7.04)
 20.21
 (3.83)
+20.06

 20.58
 (5.47)
+20.48
 19.14
 (6.08)
 10.90
 (7.64)
  8.61
 (5.96)
 +9.00

 14.37
 (7.17)
+14.36
 14.22
 (7.31)
     Springfield
112    1742  10-15-73  1449-16084  2,435  1,558  37.48  23.96   18.02    8.18
                                                                                                  (continued)

-------
                                            TABLE A-l.  (continued)
ro
o
01
Name of Water Body
Stephen A. Forbes


Storey


Sugar Creek (Curry)




Summerset




NES LANDSAT LANDSAT LANDSAT MSS Mean DN
Serial STORE! Scene Scene Area Value and (Deviation)
Number Number Date Number** Pixels (ha) GRN RED IR1 IR2
78 10-14-73 1448-16032 272 174 36
(3
+35
50 1751 10-16-73 1450-16142 70 45 37
(2
+39
178 10-15-73 1449-16084 59 38 45
(4
10-16-73 1450-16142 54 35 45
(2
+46
186 10-15-73 1449-16082 144 92 35
(2
10-16-73 1450-16142 147 94 31
(1
+35
.18
.95)
.59
.38
.81)
.75
.15
.55)
.96
.29)
.01
.17
.31)
.75
.68)
.65
20
(3
+19
22
(2
+23
36
(5
38
(3
+36
19
(2
18
(2
+20
.79
.99)
.98
.48
.92)
.88
.31
.57)
.11
.47)
.04
.85
.51)
.34
.20)
.66
16
(6
+16
19
(6
+19
31
(4
32
(2
+27
15
(4
14
(4
+16
.43
.63)
.55
.62
.69)
.07
.63
.85)
.42
.64)
.58
.95
.76)
.30
.40)
.42
9.
(7.
+9.
11.
(8.
+10.
15.
(4.
16.
(4.
+14.
7.
(5.
8.
(5.
+8.
24
95)
84
42
09)
78
47
83)
98
62)
30
86
43)
00
74)
61
     Sunfish
     Swan
126
 93
10-16-73  1450-16140    89     57
10-16-73  1450-16140    35     22
 38.12  28.20
 (1.63) (1.66)
+40.29 +28.33
 23.31   13.34
 (4.96)  (7.49)
+21.97  +12.00
 42.51  32.57   29.99   21.59
 (2.53) (2.57)  (3.41)  (5.25)
+43.49 +31.73  +26.08  +17.23
                                                                                                   (continu ed)

-------
                                             TABLE A-l.  (continued)
ro
o
NES LANDSAT
Serial STORE! Scene
Name of Water Body Number Number Date
Swan

Tampier




Third


Thunderbird




Turner

Upper Smith




172 10-15-73

23 10-14-73


10-15-73

155 10-14-73


173 10-15-73

10-16-73


102 10-15-73

180 10-15-73

10-16-73


LANDSAT
Scene
Number** Pixels
1449-16082 198

1448-16023 140


1449-16082 147

1448-16023 99


1449-16082 57

1450-16140 60


1449-16062 147

1449-16084 184

1450-16142 160


LANDSAT MSS Mean DN
Area Value and (Deviation)
(ha) GRN RED IR1 IR2
127 39.
(2.
90 39.
(3.
+38.
94 39.
(3.
63 34.
(1.
+34.
37 37.
(3.
38 34.
(2.
+38.
94 39.
(1.
118 40.
(3.
102 41.
(2.
+42.
70
00)
22
46)
54
15
14)
60
58)
06
57
14)
98
14)
00
54
89)
83
21)
41
14)
69
28.
(1.
25.
(4.
+24.
25.
(3.
20.
(2.
+19.
21.
(3.
19.
(2.
+21.
27.
(1.
28.
(2.
29.
(1.
+29.
17
95)
38
3D
64
27
70)
16
36)
34
82
35)
28
65)
39
92
76)
73
93)
96
72)
70
23.
(4.
20.
(6.
+20.
21.
(5.
16.
(5.
+16.
17.
(7.
16.
(5.
+17.
24.
(3.
24.
(7.
23.
(4.
+21.
17
08)
94
62)
64
15
58)
08
48)
22
45
43)
29
52)
65
12
42)
59
80)
22
03)
91
10.
(6.
11.
(7.
+11.
12.
(7.
7.
(7.
+8.
11.
(6.
12.
(7.
+11.
11.
(5.
11.
(6.
10.
(6.
+10.
89
60)
31
57)
66
05
14)
21
08)
05
64
88)
04
19)
17
24
10)
15
52)
65
17)
29
                                                                                                   (continued)

-------
                                             TABLE  A-l.   (continued)
00

Name of Water Body
Vandal ia City


We-Ma-Tuk




West Frankfort New


West Frankfort Old


West Loon


Wi 1 dwood

NES LANDSAT LANDSAT LANDSAT MSS Mean DN
Serial STORET Scene Scene Area Value and (Deviation)
Number Number Date Number** Pixels (ha) 6RN RED IR1 IR2
27 1764 10-14-73 1448-16032 394 252 39.
(4.
+38.
33 1761 10-15-73 1449-16084 117 75 40.
(4.
10-16-73 1450-16142 86 55 38.
(3.
+40.
31 10-14-73 1448-16035 100 64 34.
(1.
+34.
30 10-14-73 1448-16035 87 56 33.
(1.
+33.
156 10-14-73 1448-16023 109 70 35.
(3.
+35.
162 10-15-73 1449-16084 124 79 39.
(3.
15
07)
47
75
41)
04
72)
24
72
85)
18
59
53)
09
66
07)
09
52
25)
24,
(4.
+23.
29.
(4.
26.
(4.
+27.
19.
(2.
+19.
18.
(2.
+18.
19.
(4.
+18.
22,
(3,
,16
,30)
,40
,45
,96)
,81
,45)
,25
,92
.21)
,09
,89
.03)
,05
,56
,22)
,73
,62
.83)
17.
(6.
+17.
30.
(12.
21.
(6.
+20.
14.
(5.
+14.
17.
(7.
+17.
13.
(7.
+13.
16.
(6.
47
78)
53
70
28)
26
31)
71
70
60)
91
42
02)
48
00
51)
30
73
79)
9.
(8.
+10.
16.
(8.
13.
(7.
+11.
7.
(6.
+8.
10.
(7.
+10.
6.
(7.
+7.
10.
(7.
46
01)
03
56
23)
12
89)
86
39
68)
20
03
78)
53
41
17)
34
24
09)
     Wolf
17
10-14-73  1448-16023   702
449   36.17  21.73
      (4.75) (6.87)
     +35.58 +20.93
 15.85    9.08
 (8.82)  (8.44)
+16.00   '9.69
                                                                                                   (continued)

-------
                                            TABLE A-l.   (continued)
o
VD

NES LANDSAT
Serial STORET Scene
Name of Water Body Number Number Date
Wonder

Wo r ley



Yorkv
i ** • " j



69 1750 10-15-73

117 10-15-73
10-16-73


179 10-15-73

10-16-73


LANDSAT
Scene
Number**
1449-16082

1449-16084
1450-16142


1449-16084

1450-16142



Pixels
442

137
158


257

236


Area
(ha)
283

88
101


165

151


LANDSAT MSS Mean DN
Value and (Deviation)
URN
37
(1
39
(2
39
(1
+41
40
(3
42
(2
+43
.29
.95)
.45
.94)
.17
.9.5)
.06
.37
.51)
.19
.17)
.26
RED
23
(2
27
(2
28
(2
+28
29
(3
31
(1
+31
.90
.03)
.77
.34)
.78
.01)
.78
.39
.61)
.79
.93)
.12
IR1
19
(4
27
(6
27
(3
+24
27
(8
25
(3
+23
.75
.35)
.18
.81)
.57
.25)
.59
.23
.39)
.40
.25)
.26
IR2
9.50
(6.22)
13.00
(5.88)
13.77
(4.97)
+12.27
11.81
(5.95)
11.92
(5.53)
+11.10
     Zurich
154
10-14-73  1448-16023   146
93   35.01  19.38
     (2.08) (2.48)
     34.46  18.54
12.08    5.24
(4.92)  (5.36)
12.43    6.31
      *A water body's mean DN value for a particular band was calculated by summing the band's UN value for
       each pixel and then dividing the sum by the total number of pixels.

     **The multispectral scanner data from LANDSAT Scene 1449-16084 are known to be in error, a consequence
       of missing calibration data, and were not used in model development or for predictive purposes.

      +Multispectral scanner data adjusted to a common date (October 15th) through the use of regression
       models.

-------
TABLE A-2.  TROPHIC INDICATOR MEAN VALUES FOR 31 WATER BODIES SAMPLED OCTOBER 16-19, 1973

Name of Water
Body
Baldwin
Bloomington
Carlyle
Cedar
Charleston
Coffeen
Crab Orchard
Decatur
DePue
East Loon
Fox
Grass
Highland Silver
Hoi iday
Horseshoe
Long
Lou Yaeger
Marie
Old Ben Mine
Pistakee
Raccoon
Rend
Sangchris
Shelbyville
Slocum
Springfield
Storey
Vandal i a
Serial
Number
105
71
14
55
16
94
127
73
3
53
60
61
77
51
131
52
95
62
32
65
80
29
11
114
54
112
50
27
NES
STORET
Number
1763
1703
1706
1759
1708
1711
1712
1714
1752
1757
1755
1756
1740
1754
1766
1725
1726
1727
1765
1733
1762
1735
1753
1739
1758
1742
1751
1764
CHLA
(yg/liter)
11.9
56.8
19.9
5.6
18.0
5.8
46.7
21.4
42.4
26.8
37.4
46.1
5.8
67.0
99.5
61.2
8.6
70.7
24.6
66.5
10.6
15.6
15.6
12.8
241.4
17.4
30.0
13.5
COND
(umhos/cm)
457
389
359
302
519
521
235
435
590
354
472
501
191
473
547
581
200
467
1376
467
188
281
399
384
622
318
408
170
SEC
(m)
0.94
0.79
0.48
2.77
0.25
1.37
0.36
0.46
0.15
0.91
0.36
0.31
0.41
0.46
0.56
0.31
0.43
0.56
0.48
0.31
0.41
0.61
0.89
0.48
0.31
0.56
0.89
0.71
TPHOS
(mg/liter)
0.045
0.044
0.091
0.053
0.207
0.055
0.114
0.143
0.499
0.087
0.212
0.347
0.107
0.173
0.098
0.785
0.150
0.286
0.930
0.216
0.145
0.065
0.047
0.063
1.330
0.095
0.125
0.175
TON
(mg/liter)
0.714.
0.707
0.742
1.105
1.200
0.469
0.843
0.590
2.020
1.380
0.970
1.773
0.651
1.200
2.375
2.074
0.651
1.896
1.690
1.635
0.900
0.971
0.547
0.595
5.940
0.595
0.980
1.019
                                                                                        (continued)

-------
TABLE A-2.  (continued)

Name of Water
Body
Vermilion
We-Ma-Tuk
Wonder

Serial
Number
122
33
69
NES
STORE!
Number
1748
1761
1750

CHLA
(ug/liter)
27.0
8.3
198.0

COND
(pmhos/cm)
464
758
523

SEC
(m)
0.36
1.07
0.46

TPHOS
(mg/liter)
0.117
0.103
0.423

TON
(my/liter)
0.740
0.588
1.788

-------
TABLE A-3.  TROPHIC INDICATOR ANNUAL MEAN VALUES FOR 31 WATER BODIES SAMPLED THREE TIMES DURING 1973

Name of Water
Body
Baldwin
Bloomington
Carlyle
Cedar
Charleston
Coffeen
Crab Orchard
Decatur
DePue
East Loon
Fox
Grass
Highland Silver
Hoi iday
Horseshoe
Long
Lou Yaeger
Marie
Old Ben Mine
Pistakee
Raccoon
Rend
Sangchris
Shelbyville
Slbcum
Springfield
Storey
Vandalia
Serial
Number
105
71
14
55
16
94
127
73
3
53
60
61
77
51
131
52
95
62
32
65
80
29
11
114
54
112
50
27
NES
STORET
Number
1763
1703
1706
1759
1708
1711
1712
1714
1752
1757
1755
1756
1740
1754
1766
1725
1726
1727
1765
1733
1762
1735
1753
1739
1758
1742
1751
1764
CHLA
(yg/liter)
11.3
26.2
17.4
5.8
12.0
7.7
59.9
43.0
58.8
22.3
63.8
83.5
5.8
51.2
182.2
49.3
10.7
39.5
31.4
75.9
19.2
23.5
19.3
17.2
221.1
13.0
17.2
11.3
COND
(ymhos/cm)
499
448
379
380
564
514
256
518
703
446
525
564
205
594
567
596
207
488
645
524
260
306
398
430
676
373
455
179
SEC
(m)
0.99
0.89
0.56
2.54
0.23
1.12
0.46
0.51
0.25
1.27
0.36
0.48
0.28
0.38
0.43
0.43
0.25
0.81
0.56
0.36
0.41
0.74
0.64
0.99
0.33
0.43
1.04
0.56
TPHOS
(rug/liter)
0.043
0.064
0.088
0.035
0.155
0.045
0.125
0.126
0.542
0.102
0.225
0.280
0.225
0.180
0.164
0.580
0.214
0.148
0.760
0.203
0.119
0.070
0.069
0.075
0.819
0.123
0.093
0.150
TON
(mg/liter)
0.720
0.717
0.885
1.086
0.785
0.533
1.162
0.682
1.478
1.239
1.823
1.874
0.960
1.441
2.832
1.638
0.674
1.476
1.308
1.680
1.091
0.960
0.584
0.654
4.398
0.601
0.976
0.882
                                                                                           (continued)

-------
ro
                                            TABLE  A-3.   (continued)
""• 	 " — 	 — ' — ' 	 • — ~ ~" " " " ~" ------ — - -

Name of Water
Body
Vermilion
We-Ma-Tuk
Wonder

Serial
Number
122
33
69
NES
STORE!
Number
1748
1761
1750

CHLA
(ng/Hter)
31.1
8.0
98.5

COND
(umhos/cm)
546
907
610

SEC
(m)
0.48
0.86
0.36

TPHOS
(mg/liter)
0.112
0.071
0.430

TON
(my/ liter)
0.821
0.730
1.599

-------
         TABLE A-4.  TROPHIC INDICATOR AND MULTIVARIATE TROPHIC INDEX ESTIMATES FOR 145 ILLINOIS LAKES
                     BASED ON SET THREE REGRESSION MODELS
ro

Trophic Indicators
Lake Name
Anderson
Apple Canyon
Argyl e
Bakers
Bangs
Bath
Big
Big
Bracken
Calumet
Canton
Carbondale
Carlyle
Catherine
Cattail
Cedar
Cedar
Centrali a
Chain
Channel
Charleston
Chautauqua
Clear
Coal City Recreation Club
Commonwealth
Edison-Dresden Nuclear
Serial
Number
34
144
157
19
56
166
134
176
145
18
36
38
14
58
125
39
55
79
83
59
16
87
86
138

137
SEC
(m)
0.3
1.4
1.1
0.2
1.0
0.3
0.4
0.3
1.7
0.3
0.5
0.2
0.5
1.1
0.8
0.5
1.4
1.5
0.3
0.7
0.3
0.2
0.3
24.9

0.3
Multivariate
Trophic Indices
CHLA TON TPHOS PC1Y5 PC1F5
(yg/liter) (mg/liter) (nig/liter) (dimensionless)
32
35
3
18
38
3
18
12
42
29
6
1
14
67
3
2
8
24
16
91
19
15
22
2

11
2.29
0.93
0.60
4.62
0.87
1.37
0.98
1.30
0.78
2.51
0.78
2.92
0.66
1.35
1.03
0.91
1.23
1.04
1.47
1.22
1.33
1.59
1.49
0.44

0.72
0.22
0.12
0.17
1.02
0.11
0.64
0.22
0.26
0.16
0.08
0.09
1.18
0.06
0.19
2.49
0.45
0.07
0.22
0.40
0.22
0.31
0.35
0.36
0.36

0.12
0.70
-1.11
-2.45
0.14
-1.20
-0.66
-0.32
0.06
-1.27
-3.55
-1.45
-0.68
-1.61
-0.17
-0.90
-0.80
-2.55
-1.15
0.43
0.89
0.78
0.53
0.70
-7.43

-0.26
2.54
0.62
-0.68
4.24
0.27
1.90
1.51
2.26
0.38
0.64
0.50
3.09
-0.33
1.32
0.73
0.97
-0.12
0.61
2.67
1.99
2.65
2.85
2.83
-4.83

0.69
                                                                                                   (continued)

-------
                                             TABLE A-4.   (continued)
ro
i—>
en
Trophic Indicators
Lake Name
Countryside
Crab Orchard
Crane
Crooked
Crystal
Decatur
Deep
DePue
Devil 's Kitchen
Diamond
DuQuoi n
Dutchman
East Loon
Fourth Lake
Fox
Fyre
• ,/•*•
Gages
George
Glen 0. Jones
Goose
Goose (Village)
Grass
Greenville New City
Griswold
Harrisburg
Highland
Hoi iday
Serial
Number
148
127
85
149
68
73
150
3
128
57
98
49
53
151
60
170
152
108
110
101
139
61
2
158
111
153
51
SEC
(m)
0.9
0.5
0.2
0.6
1.2
0.3
2.4
0.2
4.4
1.1
0.6
2.3
1.0
0.2
0.3
1.1
1.3
1.9
3.2
0.2
1.9
0.3
0.5
0.8
0.9
1.8
0.5
Multivariate
Trophic Indices
CHLA TON TPHOS PC1Y5 PC1F5
(ng/liter) (mg/liter) (mg/liter) (dimensionless)
71
69
1
108
22
32
2
23
30
35
62
37
30
36
70
50
20
30
19
16
18
38
38
45
34
10
51
1.08
1.00
1.65
1.77
0.80
1.07
0.66
1.47
1.47
0.69
3.80
0.83
1.40
1.32
1.11
1.19
0.96
0.67
0.73
2.18
0.61
1.35
1.06
1.36
1.38
1.74
1.72
0.16
0.18
0.33
0.29
0.06
0.20
0.03
0.39
0.11
0.07
0.44
0.20
0.12
0.26
0.33
0.24
0.09
0.07
0.04
0.60
2.54
0.25
0.17
0.42
0.27
0.12
0.24
0.20
0.71
-0.61
0.20
-1.95
1.01
-4.24
1.13
-2.08
-1.53
1.48
-1.48
-0.76
1.31
1.76
-0.11
-1.99
-2.02
-2.96
1.22
-4.60
1.37
0.24
0.41
-0.12
-2.58
1.04
1.66
1.72
2.26
2.81
-0.15
2.14
-1.83
2.99
0.35
-0.09
3.35
0.20
1.18
2.87
2.41
1.52
-0.09
-0.28
-0.81
3.74
-2.49
2.44
1.68
2.00
1.59
0.05
2.49
                                                                                                      (continued)

-------
                                             TABLE A-4.   (continued)
ro
i—'
Ol

Lake Name
Horseshoe
Jack, Swan, Grass
Keithsburg
Klnkaid
Kinneman
Lake of Egypt
Lake of the Woods
Lame-Pine
Lily
Lincoln Trail
Little Grassy
Little Swan
Liverpool
Long
Long
Lower Smith
Lyerla-Autumnal
Marie
Marion
Marshall
Matanzas
Mattoon
McCollum
McGinnis
Meredosia
Mesa
Moscow
Moses
Serial
Number
1
165
92
40
168
132
115
121
136
13
119
185
88
52
177
181
120
62
129
81
89
24
159
20
10
184
164
28

SEC
(m)
0.4
0.3
1.0
6.7
2.7
1.6
0.3
2.0
0.3
4.5
3.4
0.4
0.4
0.4
0.3
0.5
0.7
0.4
1.1
0.3
0.3
0.6
1.4
0.2
0.2
2.0
0.3
1.6
Trophic
Indicators
Multivariate
Trophic Indices
CHLA TON TPHOS PC1Y5 PC1F5
(yg/liter) (mg/liter) (mg/liter) (dimensionless)
48
39
6
28
30
15
15
5
9
30
12
5
1
58
1
0
21
80
73
26
13
8
30
104
4
22
19
50
1.81
1.38
0.94
0.40
1.42
0.59
1.75
1.98
1.50
1.35
0.95
0.95
1.31
1.51
1.44
0.92
1.17
1.29
2.27
1.55
1.34
0.62
0.85
10.59
1.84
0.76
1.29
2.44
0.98
0.30
2.34
0.01
6.09
0.04
0.74
41.56
0.98
0.12
0.04
0.21
1.05
0.30
0.40
0.36
0.92
0.26
0.48
0.48
0.28
0.05
0.10
3.63
0.26
0.04
0.35
0.56
1.32
1.21
-1.15
-4.59
-6.18
-2.55
0.55
-0.59
-1.71
-2.11
-3.20
-0.71
-1.53
1.33
-1.00
-1.65
-0.64
1.59
0.91
1.08
0.23
-1.79
0.37
3.69
-1.14
-2.41
0.17
0.22
3.19
2.92
0.40
-2.56
-2.26
-0.76
2.99
0.65
1.38
0.23
-1.68
1.27
1.24
2.39
1.82
0.64
1.53
2.73
2.64
3.05
2.41
-0.16
0.37
6.85
2.06
-0.42
2.30
2.10
                                                                                                     (continued)

-------
                                              TABLE A-4.   (continued)
INJ
I—'
—I
Trophic Indicators
Lake Name
Mound
Murphysboro
New Pittsfield
Nipper sink
Old Ben Mine
Olney East Fork
Olney New
Open Pond
Otter
Pana
Paradise
Paris Twin
Pekin
Petite
Pierce
Pinckneyville
Pistakee
Powerton Cooling
Quiver
Raccoon
Rend
Rice
Round
Saganashkee
Sahara Coal Company
Sam Dale
Sam Parr
Sand
Sanganois

Serial
Number
163
37
100
63
32
106
107
174
167
113
15
25
116
64
130
99
65
182
90
80
29
35
66
21
175
124
41
147
9

SEC
(m)
0.4
1.7
0.3
0.3
0.6
1.7
1.6
1.3
0.7
0.9
0.4
1.5
0.3
0.4
1.0
0.6
0.4
0.5
0.3
0.4
0.5
0.3
1.4
0.4
0.7
1.0
1.6
1.6
0.3

CHLA
dig/liter)
50
34
1
51
41
29
38
2
15
4
22
36
2
50
54
48
67
78
9
16
12
70
2
76
267
66
58
21
3

TON
(mg/liter)
1.34
1.25
1.15
1.27
1.35
0.66
1.05
0.87
1.00
0.67
0.92
1.62
1.30
1.08
0.95
0.91
1.24
0.97
1.03
0.94
0.85
1.40
0.66
1.62
2.23
1.90
1.63
0.99
1.67

Multivariate
Trophic Indices
TPHOS PC1Y5 PC1F5
(mg/liter) (dimensionless)
0.33
0.20
0.15
0.28
0.49
0.06
0.56
3.61
0.62
0.23
0.15
0.49
0.55
0.18
0.13
0.13
0.25
0.22
0.22
0.10
0.10
0.30
0.05
0.33
30.82
0.23
1.49
0.08
0.65

1.18
-0.95
-1.54
1.58
0.56
-2.00
-0.60
-1.72
-0.48
-1.99
0.01
-0.31
-0.69
0.77
-0.32
0.10
1.16
0.94
-0.05
-0.60
1.07
1.83
-3.65
1.84
-6.51
0.48
0.37
-2.22
-1.50

2.72
0.92
1.10
2.48
2.16
-0.28
0.95
-0.17
1.23
-0.23
1.50
1.45
1.81
1.99
1.19
1.43
2.16
1.79
1.77
1.23
0.35
3.11
-1.54
3.14
-2.13
2.23
1.86
-0.18
1.73
(continued)

-------
                                             TABLE  A-4.   (continued)
ro
i—i
oo

Trophic Indicators
Lake Name
Sara
Sawmill
Senachwine
Shelbyville
Skokie Lagoons
Sloe urn
Snyder's Hunting
South Wilmington
Spri ng
Spri ng
Spri ng
Spri ng
Spring Arbor
St Mary's
Stephen A. Forbes
Storey
Sugar Creek
Summerset
Sunfish
Swan
Swan
Tampier
Third
Thunderbird
Turner
Upper Smith
Vandal i a
We-Ma-Tuk
West Frankfort New
Serial
Number
26
103
104
114
22
54
142
140
4
8
67
118
143
146
78
50
178
186
126
93
172
23
155
173
102
180
27
33
31
SEC
(m)
2.4
0.2
0.2
0.6
0.6
0.3
0.9
7.9
0.2
0.2
0.4
0.4
2.6
1.4
1.4
1.0
0.3
0.8
0.4
0.8
0.2
0.6
0.7
2.2
0.2
0.3
1.1
0.6
1.1
CHLA TON
(yg/liter) (mg/liter)
21
51
58
7
5
253
15
1
30
16
3
81
31
67
34
45
15
64
11
9
40
30
79
11
46
19
18
10
26
1.15
3.06
1.74
0.80
1.64
6.47
1.67
0.44
2.18
1.30
0.95
1.29
1.36
0.92
1.10
0.84
2.10
1.51
1.10
0.92
2.09
1.07
2.37
0.64
2.71
1.09
0.70
0.83
1.49
Multivariate
Trophic Indices
TPHOS PC1Y5 PC1F5
(mg/liter) (dimensionless)
0.15
0.91
0.45
0.07
5.46
1.48
0.96
0.20
1.01
0.28
0.21
0.26
0.97
0.32
0.11
0.16
1.18
0.19
0.42
3.09
0.67
0.41
0.29
0.10
0.95
0.20
0.07
0.25
0.11
-1.82
3.00
2.72
-1.65
-0.64
4.31
-0.15
-6.15
1.73
0.73
-0.71
1.53
-0.80
-0.70
-1.14
-0.68
-2.00
0.33
-0.00
-2.84
2.11
-0.03
1.18
-2.67
2.51
-0.04
-1.70
-0.91
-1.17
0.25
5.04
3.96
0.03
1.67
6.78
1.45
-3.75
3.82
2.61
1.27
2.81
0.75
1.14
0.74
0.95
1.72
1.83
1.81
-0.52
4.00
1.65
2.73
-0.84
4.59
1.89
-0.01
0.81
0.92
                                                                                                    (continued)

-------
                                            TABLE A-4.  (continued)
ro

Trophic Indicators
Lake Name
West Frankfort Old
West Loon
Wolf
Wonder
Worl ey
Yorkey
Zurich
Serial
Number
30
156
17
69
117
179
154
SEC
(m)
1.2
2.0
1.2
0.4
0.3
0.3
1.6
CHLA TON
(ug/liter) (nig/liter)
79
3
13
77
23
9
1
3.22
0.85
0.98
1.74
1.92
1.29
0.99
Multi
Trophic
variate
Indices
TPHOS PC1Y5 PC1F5
(my/liter) (dimensionless)
0.40
0.04
0.08
0.37
0.88
0.30
0.09
0.98
-3.74
-1.80
2.03
1.05
-0.13
-3.86
2.90
-1.21
0.21
3.37
3.37
2.14
-1.30

-------
           TABLE A-5.  GROUP AND INDIVIDUAL LAKE WATER QUALITY AND ANCILLARY DATA VALUES FOR SELECTED
                       ILLINOIS WATER BODIES CLASSIFIED BY COMPLETE LINKAGE CLUSTERING ON FOUR SPECTRAL
                       ATTRIBUTES (CRN, RED, IR1, IR2)
ro
ro
o
LAKE NAME -No.
Centra Ha -079
Harrlsburg -111
Fyre -170
Apple Canyon -144
McCullom -159
Dutchman -049
Thunder-bird -173
Bracken -145
la mean
Countryside -148
Pierce -130
George -108
Olney East Fork -106
Lake of Egypt -132
Vandalla -027
Ib mean
Bangs -056
Crystal -068
Channel -059
Diamond -057
Long -052
P1 stakes -065
Rend -029
Shelbyvllle -114
Holiday -051
Ic mean
K1nca1d -040
Id mean
Cluster 1 mean
SPECTRAL INDEX
SIGNATURES
Raftoctanca Scaled %
6RN RED IR1 IR2
16 18 26 32
14 20 27 28
20 19 29 28
21 18 24 24
23 20 24 24
23 16 28 34
25 21 24 32
30 21 31 30
22 19 27 29
25 20 27 19
26 22 26 19
30 21 24 24
31 22 23 22
33 26 22 22
30 28 24 22
29 23 24 21
21 16 12 5
20 17 13 10
22 18 21 8
30 22 16 8
17 25 19 6
23 26 22 7
23 29 14 6
22 28 14 10
13 23 22 14
21 23 17 10
50 19 17 15
50 19 17 15
25 22 22 19
GROUND TRUTH
(1977)
Suipendtd
wlidj me/I
Tot Vol.
15 3
9 6
4 2
9 4
11 10
7 7
3 0
4 2
8 3
7 4
16 14
3 3
14 11
8 8
10 9
1 0
1 0
10 6

S«c.
Depth
m.
.71
.74
1.65
1.04
.68
1.40
2.71
1.59
.90
1.40
.60
2.26
.80
.87
1.13
1.97
1.97
1.27
OBSERVED PROBLEMS
1- Minimum,4-Savare
ME < I "S.
332
2 1 3
2 2 3
223
2 2 3
1 1 3
1 2 2
2 2 3
1.9 1.9 2.7
2 3 3
1 2 2
1 2 3
2 1 3
4 2 1
2.0 2.0 2.4
223
1 2 2
1 3 2
2 3 2
232
3 3 1
2 1 2
2 2 1
3 3 1
2.0 2.4 1.8
1 1 2
1 1 2
1.9 2.1 2.3
NES DATA
1973
MC. chla
m. ug/l
-
.71 13
.71 13
.31 61
.31 66
.61 15
.48 12
.43 39
-
.49 33
MORPHOLOGY
Depth) matert)
Mam Max.
2.1 7.5
3.1 9.2
4.3 11.0
9.2 21.4
1.2 2.9
2.3 8.8
10.7 18.3
4.2 10.1
4.6 11.2
2.3 3.7
3.8 11.0
7.0 17.7
4.6 12.2
5.6 15.9
4.2 11.3
HYDRAULIC FACTORS
U I* il I!
11 II iJ II
4.7 .8 .18 24
26.5 .7 .17 10
65.1 3.2 .07 4
33.8 1.7 .10 4
14.9 .7 .27 17
25.8 .7 .19 10
7.5 .4 .35 68
12.6 .6 .26 20
26.0 1.0 .20 12
30.3 1.5 .18 8
7.6 .4 .43 50
24.5 1.2 .16 5
42.8 1.4 .07 12
76.3 2.2 .03 5
16.2 .6 .18 8
4.6 12.0 32.9 1.3 .18 9
4.2 7.6 130.1 6.4 .04 2
4.1 12.5 30.3 1.5 .01 8
4.2 12.2 - ...
2.9 7.3 109.0 5.4 .05 2
4.0 9.2 5.5 .3 .45 46
1.8 9.2
3.0 9.5 18.1 .6 .05 35
5.8 19.8 9.7 .4 .06 13
2.7 5.8 2.1 .1 .10 296
3.6 10.3
8.6 24.4
8.6 24.4
4.4 11.6
43.5 2.0 .11 58
56.9 1.7 .04 7
56.9 1.7 .04 7
34.9 1.5 .16 30
BIOTA
§1
*i
<°
19.7
.9
.1
6.9
3.4
1.4
.9
.2
.4
1.2
.6
.1
2.6
2.5
1.4
.3
.3
2.5
                                                                                                   (continued)

-------
                                            TABLE A-5.  (continued)
LAKE NAME -No.
SPECTRAL INDEX
SIGNATURES
Reflectance Scaled %
GRN RED IR1 IR2
GROUND TRUTH
(1977)
Suspended
solids mg/l
Tot. Vol.
Sec.
Depth
m.
OBSERVED PROBLEMS
1- Minimum, 4-Severe
NES DATA
1973
tec. chla
m. "9/1
MORPHOLOGY
Depth! meters)
Mean Max.
HYDRAULIC FACTORS
1! 1! II ll
BIOTA
Algal count
1000/ml.
ro
ro
Petite
Pinckneyvnie
Marie
Crab Orchard
Powerton Cooling
Grass
Nlppersink
2a mean
Saganashkee
Wonder
Greenville New C
R1ce
Spring
Mound
2b mean
Grlswold
Old Ben Mine
Olney New
St. Marys
Storey
2c mean
Sam Parr
Spring Arbor
Snyders Hunting
2d mean
Cluster 2 mean
-064
-099
-062
-127
-182
-061
-063

-021
-069
-002
-035
-118
-163

-158
-032
-107
-146
-050

-041
-143
-142


30
34
30
30
33
22
25
29
24
24
27
36
36
34
30
20
24
22
44
37
29
15
9
8
11
27
34
32
32
29
30
35
35
32
29
30
31
39
35
38
34
24
29
20
27
30
27
15
13
23
17
29
28
28
31
24
24
24
24
26
33
35
28
38
36
40
35
34
38
36
44
34
37
41
32
33
35
33
14
15
13
8
6
9
7
10
18
19
19
16
16
24
19
32
34
41
35
27
34
48
47
44
46
23
.
3
-
26
-
-
-
14
54
49
15
-
-
-
39
27
-
4
-
15
15
3
-
-
3
22
.
1
-
17
-
.
-
9
33
16
6
-
-
-
18
21
-
2
-
9
11
2
-
-
2
12
.
2.49
-
.52
.
-
-
1.51
.14
.31
.73
-
-
-
.39
.47
-
1.03
-
.59
.70
1.65
-
-
1.65
.88
3
1
2
3
1
4
4
2.6
1
3
2
3
4
-
2.6
2
3
2
-
3
2.5
2
2
2
2.0
2.5
3
2
3
3
2
3
3
2.7
2
3
2
3
2
-
2.4
2
3
2
-
3
2.5
3
2
-
2.5
2.6
1
3
2
2
1
3
1
1.9
2
3
1
1
2
-
1.8
3
3
3
-
3
3.0
2
3
4
3.0
2.3
_
.
.56
.36
_
.31

.40
_
.46
_
.
.
-
.46
„
.49

-
-
.49
„
_
-
-
.43
_
_
70
47
_
46

54
_
198
_
-
.
-
198
_
24

.
-
24
_
.
-
-
77
2.3
3.7
2.8
2.8

0.8
.9
2.2
1.2
3.8
4.0
.8
1.4
.6
2.2
2.2
1.2
3.4
3.1
4.2
2.8
3.1
3.7
1.2
2.7
2.4
6.7
8.5
10.7
7.5

1.8
2.1
6.2
2.7
10.4
7.5
1.4
3.4
-
5.1
3.7
1.5
9.8
3.7
11.0
5.7
7.0
15.3
2.4
8.2
6.1
_
19.8
_
17.7

_
.
18.7
11.0
12.7
13.9
17.4
44.1
-
19.8
29.1
_
21.5
30.6
12.4
23.4
13.9
73.2
6.8
31.2
23.1
_
.6
_
.5

_
_
.6
.5
.6
.6
.9
2.1
-
1.0
1.4
.
.7
1.5
.6
.9
.5
2.1
.2
1.0
.9
_
.20

.08

.
_
.14
.34
.08
.05
.06
.
-
.13
.06
.
.06
.05
.09
.07
.09
.07
.55
.25
.14
-
26

22

„
_
24
58
20
9
37
14
-
23
9
.
24
8
21
14
29
5
75
14
25
_
.4

25.6

_
_
13.0
1.8
2.2
11.8

.
-
5.3
.4
_
3.8

5.3
3.2
9.5
_
-
9.5
7.7
                                                                                                    (continued)

-------
                                            TABLE A-5.   (continued)
LAKE NAME -No.
SPECTRAL INDEX
SIGNATURES
R«f toctanc* Scaled %
CRN RED IR1 IR2
GROUND TRUTH
(1977)
Suipendtd
K>lid» mg/l
Tot Vol.
SM.
Depth
m.
OBSERVED PROBLEMS
1- Mintmum,4-S«v«fe
»? < Z a
NES DATA
1973
we chta
m. ufl/l
MORPHOLOGY
D«pth(rmtwt)
Mom Max.
HYDRAULIC FACTORS
•
S« I, li |l
II 11 it II
BIOTA
IE
if
ro
ro
ro
East Loon
Sam Dale
Summerset
Third
Glen 0. Jones
Mesa
Stephen A Forbes
Wolf
3a mean
Devils Kitchen
Lincoln Trail
Little Grassy
3b mean
Marlon
Paris East
Moses
Murphysboro
Sara
DuQuoln
West Frankfort 0
3c mean
Sand
West Loon
Deep
Zurlck
Round
Catherine
Gages
Cedar
West Frankfort N
Highland
3d mean
Cluster 3 mean
-053
-124
-186
-155
-110
-184
-078
-017

-128
-013
-119

-129
-025
-028
-037
-026
-098
-030

-147
-156
-150
-154
-066
-058
-152
-055
-031
-153


10
8
12
6
18
20
14
14
13
3
5
10
6
7
8
2
11
9
0
1
5
13
12
18
8
20
12
14
6
7
0
11
10
14
11
13
11
10
14
14
18
13
0
1
5
2
12
14
9
13
10
13
6
11
9
9
10
8
16
9
12
9
10
2
9
10
17
22
17
16
15
15
20
17
18
14
16
10
13
29
28
27
23
20
24
24
25
8
4
3
0
5
13
9
7
12
2
6
15
17
19
9
10
20
17
21
20
17
25
27
17
23
30
37
35
29
30
23
25
30
6
6
4
0
3
5
5
9
11
3
5
16
2
16
.
.
6
.
12
8
9
0
2
2
1
6
7
12
18
2
13
3
9
10
2
2
5
9
.
7
3
3
-
6
7
2
7
.
..
6
.
9
8
6
0
2
1
1
4
4
9
15
1
12
3
7
8
2
2
5
9
.
12
3
2
-
5
6
1.53
.81

.
1.00
.
.89
1.47
1.14
4.52
2.20
3.20
3.31
.84
1.18
.47
.51
1.83
.59
1.31
.95
.84
2.08
2.15
1.24
.92
.
.64
1.30
1.42
-
1.32
1.43
1
3
1
2
1
1
2
2
1.6
1
1
1
1.0
3
2
2
2
1
3
1
2.0
2
1
1
1
2
1
2
1
1
1
1.3
1.5
3
3
2
4
3
1
2
1
2.4
1
2
1
1.3
4
2
2
3
2
2
3
2.6
2
2
1
1
2
3
3
2
2
2
2.0
2.2
3 .91
3
2
2
2
4
3
3
2.7 .91
1
3
1
1.7
3
2
3
1
3
3
4
2.7
3
3
3
2
2
2
3
3 2.77
3
3
2.7 2.77
2.6 1.84
27
,
.
.
.
-
.
-
27
.
.
-
-
m
.
.
-
-
.
-
-
_
.
-
.
-
_
-
6
-
-
6
17
1.8
2.4
6.1
5.7
4.4
4.0
4.3
2.1
3.8
11.0
3.8
7.8
7.5
4.3
3.1
2.7
4.3
6.1
2.1
2.4
3.6
3.0
6.4
5.9
3.3
3.5
5.1
3.2
1.2
2.4
3.2
3.7
4.1
7.9
5.5
14.3
18.9
9.1
7.9
8.5
6.4
9.8
27.4
12.5
23.5
21.1
7.0
8.1
6.4
9.8
15.8
9.1
6.1
8.9
10.1
11.3
15.8
9.8
10.7
12.2
14.6
12.2
4.6
10.7
11.2
11.3
4.7
10.2
38.6
90.0
48.1
67.2
16.2
-
39.3
76.1
26.2
81.2
61.2
22.6
4.0
23.5
35.4
47.2
7.4
13.9
22.0
145.0
211.3
196.2
60.5
150.7
.
36.1
48.7
10.7
50.3
90.9
53.8
.2
.3
1.9
4.4
1.3
2.2
.6
-
1.5
2.1
.9
2.3
1.8
.6
.2
.7
1.1
1.9
.2
.4
.7
7.1
10.4
9.7
3.0
7.4
.
1.7
1.7
.3
2.5
4.2
2.3
.70
.35
.95
.43
.10
.07
.18
-
.40
.04
.18
.04
.09
.18
.74
.19
.13
.07
.43
.38
.30
.03
.03
.03
.07
.03
-
.15
.10
.32
.43
.13
.32
54
50
10
3
5
6
31
-
9
5
15
5
6
17
32
27
11
5
86
46
32
2
1
1
4
2
.
7
5
59
5
7
19
2.3
7.2
-
-
.8
-
2.9
.8
2.8
.1
.2
1.0
.4
.4
1.5
23.7
6.9
.2
1.0
2.8
5.2
.1
1.3
.2
.5
.5
-
1.5
.2
.2
-
.6
2.3
                                                                                                    (continued)

-------
                                             TABLE A-5.  (continued)
LAKE NAME -No.
SPECTRAL INDEX
SIGNATURES
Reflectance Scaled %
CRN RED IR1 IR2
GROUND TRUTH
(1977)
Suspended
solidi mg/l
Tot Vol.
Sec.
Depth
m.
OBSERVED PROBLEMS
1- Minimum,4-Severe
NES DATA
1973
sec. chla
m. ug/l
MORPHOLOGY
Depth(meteri) '
Mean Max.
HYDRAULIC FACTORS
U It M M
£ §• » E ^-£ =-i
S 8 O '.P > a* u. *
BIOTA
Algal count
1000/ml.
ro
r\>
CO
Charleston
Spring
Quiver
Little Swan
Spring
Chain
Clear
Moscow
4a mean
Oepue
Marshall
B1g
Fourth
Jack, Swan, Gras
4b mean
Anderson
Upper Smith
Canton
Raccoon
Senachwlne
4c mean
Decatur
Fox
Mattoon
Paradise
Commonwealth Edi
Carlyle
4d mean
Cluster 4 mean
-016
-008
-090
-185
-067
-083
-086
-164

-003
-081
-134
-151
-165

-034
-180
-036
-080
-104

-073
-060
-024
-015
-137
-014


48
50
47
52
52
53
52
52
51
45
44
47
47
46
46
57
54
57
63
49
56
34
34
46
34
46
68
44
49
55
57
55
56
58
56
55
53
56
53
50
48
53
49
51
56
54
55
59
57
56
43
38
45
44
53
59
47
53
47
47
43
45
45
53
51
50
48
48
50
43
43
45
46
46
45
40
40
44
43
29
27
28
34
24
27
34
41
25
23
26
29
29
29
26
29
27
26
29
28
17
21
24
18
24
24
16
10
18
12
4
18
20
5
4
11
21
63
104
127
-
17
-
.
-
78
_
120
-
-
-
120
95
-
15
22
97
57
36
.
12
33
.
-
27
62
11
83
29
.
4
.
_
-
32
_
27
-
-
-
27
37
-
7
6
40
23
12
.
4
11
_
-
9
23
.23
.19
.07
.
.71
-
.
-
.30
_
.11
-
.
-
.11
.12
-
.75
.59
.10
.39
.28
_
.55
.23
.
-
.34
.28
4
3
4
2
3
4
4

3.4
3
4
-
2
4
3.3
3
2
3
3
4
3.0
4
3
2
4
_
2
3.0
3.2
1
2
2
3
2
2
2

2.0
3
1
-
1
-
1.7
3
2
3
2
2
2.4
2
3
2
1
_
2
2.0
2.1
1
2
1
3
1
1
1

1.4
1
2
.
3
1
1.7
1
2
2
3
1
1.8
1
1
2
2
_
1
1.4
1.6
.25
.
.
.
-
.
.
-
.25
.15
.
.
-
-
.15
_
-
-
.41
-
.41
.46
.36
-
_
_
.48
.43
.37
18

_
.
-
.
„
-
18
58
_
.
1.2
-
58
„
-
-
10
-
10
43
38
.
_
.
20
33
31
.9
.9
.8
2.4
3.2
-
.5

1.4
.9
.3
.
1.8
1.2
.8
1.1
1.2
4.3
1.2
.3
1.6
2.2
1.7
3.2
2.3
1.8
3.3
2.4
1.7
4.3
4.3
1.2
9.5
10.7
.
.9

5.1
1.8
1.5
_
45.0
-
1.6
1.6
1.8
10.7
3.7
1.5
3.9
7.0
6.7
10.7
7.0
4.9
10,. 7
7.8
4.9
.1

_
10.9
6.8
.
_
.
5.9
.
_
.
2.2
-
45.0
43.4
-
11.1
3.9
-
19.5
1.1
.4
9.6
3.5
.
5.0
3.9
11.7
.0

_
.5
.3
_
_
_
.3
.
_
_
.12
-
2.2
2.1
-
.6
.1
-
.9
.1
_
.4
.1
_
.2
.2
.6
8.50

_
.30
.42
-
_
_
3.07
.
_
.
6
-
.12
.10
-
.26
.60
-
.32
5.00
_
.23
.80
_
.06
1.52
1.49
2,083

.
35
56
.
»
_
725
.
»
.
.
-
6
18
-
57
129
-
98
112
»
13
37
.
26
54
234
.2
5.4
.2
-
2.4
-
.
.
2.1
.
1.0
_

-
1.0
71.3
-
3.7
1.5
.7
19.3
5.8
_
6.2
.3
.
-
4.1
6.6
                                                                                                      (continued)

-------
                                            TABLE  A-5.   (continued)
ro
no
LAKE NAME -No.
Argyle -157
Pana -113
He-Ma-Tuk -033
Cedar -039
Sunflsh -126
5a mean
Dtter -167
f ampler -023
Horseshoe -001
5b mean
Sawmill -103
'urner -102
Swan -172
Spring -004
.ake of the Wood -115
Jorley -117
-yerala-Autumnal -120
>ooked -149
>c mean
:atta11 -125
Celthsburg -092
Ipen Pond -174
ikokle Lagoons -022
id mean
1cG1nn1s -020
i locum -054
.aRue-Plne -121
ie mean
Muster 5 mean
SPECTRAL INDEX
SIGNATURES
Reflectance Scaled %
CRN RED IR1 IR2
44 42 37 37
44 44 39 36
40 44 39 33
40 50 44 39
40 48 45 34
42 46 41 36
36 39 45 41
34 36 41 34
32 36 51 37
34 38 46 37
37 49 55 26
36 47 55 29
37 48 51 27
36 47 55 35
50 54 58 36
45 50 58 36
47 42 55 45
66 38 56 24
44 47 55 32
35 42 54 58
35 39 52 58
40 41 57 65
42 43 69 64
38 41 58 61
30 31 74 39
39 22 65 22
24 27 77 95
31 27 72 52
40 42 54 41
GROUND Tl
11977)
Suspended
wild. my/I
Tot Vol.
4 2
4 3
33 21
14 9
27 14
27 18
27 16
31 16
31 16
45 26
114 72
37 22
65 40
25 21
25 21
32 22
*UTH
Sec.
Depth
m.
1.90
1.94
.33
1.37
.33
.33
.33
.30
.30
.08
.09
.25
.14
.34
.34
.50
OBSERVED PROBLEMS
1- Minimum,4-Severe
i! * 11
*6 < f-fi.
322
332
223
1 2 1
2 2 1
2.2 2.2 1.8
3 - 3
1 2 1
333
2.3 2.5 2.3
4 1 1
1 3
3 1 1
4 2 1
4 3 1
3 3 3
232
3.3 2.0 1.7
323
332
4 4 1
3.3 3.0 2.0
1 3 4
4 4 1
244
2.3 3.7 3.0
2.7 2.5 2.0
NES DATA
1873
we. chla
m. u«/l
1.07 8
_
-
-
.31 241
.31 241
.69 125
MORPHOLOGY
Depth(meteri)
Mem Max.
5.3 11.6
4.2 11.6
1.8 7.6
7.0 12.2
1.8
4.6 9.0
.6 1.2
1.5 4.9
1.1 1.7
1.1 2.6
1.4 3.4
.5 .9
.5 .9
.9 3.1
4.3 9.8
1.5 3.6
.3 1.5
.8 1.8
.8 1.8
.6 1.7
.5 1.2
1.2 2.7
.6 1.8
.8 2.0
1.8 4.3
HYDRAULIC FACTORS
1* !' '1 Si
h II i£ II
12.1 .6 .45 32
.2 .0 4.00 758
2.2 .1 .14 289
39.4 1.1 .07 10
13.5 .5 1.17 272
15.9 .8 .28 40
15.9 .8 .28 40
44.1 2.1 .08 14
15.9 .5 .27 24
30.0 1.1 .12 19
9.0 .5 .48 70
4.8 .2 .70 53
6.9 .3 .59 62
13.1 .7 .72 143
BIOTA
Algal count
1000/ml.
.2
13.3
1.3
4.9
8.3
14.2
11.3
2.9
2.9
.7
7.7
13.8
7.4
30.5
30.5
11.4
                                                                                                    (continued)

-------
                                            TABLE A-5.   (continued)
ro
LAKE NAME -No.
B1g -176
fatanza -089
Vorkey -179
"hautauqua -087
Goose -101
Bath -166
Pekln -116
Lower Smith -181
Crane -085
Long -177
-Iverpool -088
Bakers -019
6a mean
L1ly -136
Sanganols -009
Carbondale -038
Sugar Creek -178
Meredosla -010
New Plttsfleld -100
6b mean
Coal City Recrea -138
South Wilmington -140
Soose Village -139
Swan -093
6c mean
Calumet -018
dnneman -168
Sahara Coal Comp -175
6d mean
Cluster 6 mean
RC:mr/4848/sp
SPECTRAL INDEX GROUND TRUTH OBSERVED PRO
SIGNAIUHtS |1»//| 1.Mlnl««,m.«
Raf lactanca Scaled * Suspended Sac. •
iolidsmg/1 Depth ^f &
CRN RED IR1 IR2 Tot Vol. m. «l <
57 60 50 26 	
56 60 50 26 68 20 .11 4 2
57 60 51 29 - - - 2
57 61 54 26 - - - 4 2
53 61 59 28 4 1
56 59 58 39 	
56 61 57 38 - - - 4 1
57 61 51 39 - - - 2 1
67 72 58 30 - - - 4
65 67 58 35 	
60 66 63 48 4
69 59 76 35 - - - 1 2
59 62 57 33 68 20 .11 3.2 1.5
65 75 65 47 3 2
68 75 64 41 - - - 4 2
67 72 73 42 2 2
72 80 72 48 - - -
75 84 60 29 150 39 .11 4 3
71 76 51 28 - - - 3 2
70 77 68 39 150 39 .11 3.2 2.2
85 49 48 61 - - - 2 1
75 49 44 53 2 1
66 63 60 70 - - - 2 1
58 62 65 65 4 2
71 56 54 62 - - - 2.5 1.3
100 100 60 27 - - - 4 1
89 67 81 80
83 97 100 100
91 88 80 69 - - - 4 1
67 68 62 44 58 17 .11 3.1 1.6
BLEMS NESDATA MORPHOLOGY HYDRAULIC FACTORS

— ueptn(niater») || g 5 a is o>5
|| tac. chla filfc * £• 1 2
I •& m. ug/l Maan Max. sffi'S > 5? E £
2 - 1.5 2.4
1 - - 1.2 4.6 - - - -
1 - .6 1.2
1 . . ....
1 - - .5 .9 - - - -
2 .6 1.2
1 - .6 1.2
4 - 1.1 4.9 23.1 1.1 .15 11
BIOTA
s
§1
ll
-
1.5 - - .9 2.3 23.1 1.1 .15 11
1 - - 1.2 2.1 	
1 - - - 	
2 - 2.4 6.4 17.2 .5 .25 22 .2
1 .8 1.5 164.4
1 - 3.8 10.3 12.7 - .25 30 .8
1.2 - - 2.0 5.0 14.9 .5 .25 26
2 - - 8.7 17.3 - ...
1 . . . . . ...
1 - 7.6 19.8 - ...
1 - - - - .3 .01
1.3 - - 8.0 18.6 .3 .01
1 - 2.4 3.1
1 - - 2.4 3.1 - - - -
1.4 - - 2.4 5.5 13.2 .56 .22 21
55.1
-
-
55.1

-------
                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing}
 1. REPORT NO.
  EPA-600/3-79-123
                                                           3. RECIPIENT'S ACCESSION-NO.
  TITLE AND SUBTITLE
 TROPHIC CLASSIFICATION OF SELECTED ILLINOIS WATER
 BODIES:  Lake  Classification Through Amalgamation of
 LANDSAT Multispectral  Scanner and Contact-Sensed Data
             5. REPORT DATE
                December 1979
             6. PERFORMING ORGANIZATION CODE
  . AUTHOR(S)
 D. H. P. Boland,  D.  J.  Schaeffer*, D. F. Sefton*,
 R. P. Clarke*, and R. J.  Blackwell**
             8. PERFORMING ORGANIZATION REPORT NO.
 9. PERFORMING ORGANIZATION NAME AND ADDRESS
 Environmental Monitoring and Support Laboratory
 Office of  Research  and  Development
 U.S. Environmental  Protection Agency
 Las Vegas, Nevada   89114
             10. PROGRAM ELEMENT NO.
                 1BD613
             11. CONTRACT/GRANT NO.
 12. SPONSORING AGENCY NAME AND ADDRESS
 U.S. Environmental  Protection Agency—Las Vegas
 Office of Research  and  Development
 Environmental Monitoring and Support Laboratory
 Las Vegas,  Nevada   89114
             13. TYPE OF REPORT AND PERIOD COVERED
                  Final  1976-1978
             14. SPONSORING AGENCY CODE
                 EPA/600/07
 15. SUPPLEMENTARY NOTES
 Jointly sponsored with  the Division of Water Pollution Control,  Illinois  Environmental
 Protection Agency,  Springfield, IL 62706    *Illinois EPA  **Jet Propulsion Laboratory
 16. ABSTRACT
      A project was  initiated to determine the feasibilwty of assessing  and classifying
 a group of  Illinois lakes through the utilization of a combination  of contact- and
 satellite-acquired  data.   LANDSAT multispectral scanner  (MSS)  digital multidate data
 for 145 Illinois  lakes  were extracted from computer-compatible tapes  and  adjusted
 through regression  analysis to a common acquisition date.  Next,  MSS  lake pixel counts
 were converted to lake  surface area estimates.  Regression models employing transformed
 Mss bands as  independent  variables were developed for the estimation  of several water
 quality parameters  and  two multivariate trophic state indices.  The water quality
 parameter estimates were  then used to develop lake rankings that, when  evaluated, were
 found to be in general  agreement with ancillary data.  Complete linkage-based  cluster
 analyses of the raw MSS data and the LANDSAT-derived water quality  parameter estimates
 for the 145 lakes resulted in the identification of physically significant lake groups,
 each of which may be characterized by its overall quality, physical and chemical
 properties, biology, watershed factors, morphology, and use impairment.   LANDSAT, when
 used with the appropriate calibration data, is capable of providing a comprehensive,
 objective, rapidly  acquired, synoptic view of lacustrine quality  and  use  impairment.
 It is a flexible, cost-effective means for monitoring lakes on a  Statewide basis.
 7.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.IDENTIFIERS/OPEN ENDED TERMS
                          c.  cos AT I Field/Group
 water quality, limnology,  lakes,  artificial
 satellites, remote sensing, multivariate
 analysis, mapping, classifiers
  eutrophication,  LANDSAT
  image processing,
  trophic state  index,
  multispectral  scanner,
  Illinois lakes,
  lake classification
  08H
  20F
 8. DISTRIBUTION STATEMENT

        RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)'

   UNCLASSIFIED	
21. NO. OF PAGES

     244
                                              2O. SECURITY CLASS (This page)

                                                 UNCLASSIFIED
                                                                        22. PRICE
EPA Form 222O-1 (9-73)
                                                      *U.S. GOVERNMENT PRINTING OFFICE: 1980-685-124

-------