FOREST SERVICE
US DEPARTMENT OF AGRICULTURE
'4 OFFICE OF RESEARCH AND DEVELOPMENT
^ US. ENVIRONMENTAL PROTECTION AGENCY
SILVICULTURAL ACTIVITIES
AND NON-POINT
POLLUTION ABATEMENT:
A Cost-Effectiveness
Analysis Procedure.
EPA-600/8-77-018
November 1977
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a 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 "SPECIAL" REPORTS series. This series is
reserved for reports targeted to meet the technical information needs of specific
user groups. The series includes problem-oriented reports, research application
reports, and executive summary documents. Examples include state-of-the-art
analyses, technology assessments, design manuals, user manuals, and reports
on the results of major research and development efforts.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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Silvicultural Activities and
Non~Pbint Pbllution Abatement:
A Cost-Effectiveness Analysis Procedure.
Authored by a Committee of Scientists of the
United States Department of Agriculture, Forest Service.
Robert McDonald, Denver, Colorado Coordinator
Greg Alward, Fort Collins, Colorado Economics
William Arlen, Asheville, North Carolina
Randy Perkins, Wenatchee, Washington \ Silviculture
Glen Parham, Tallahassee, Florida
Leland Fansher, Denver, Colorado Engineering
Ecoregion descriptions were authored by Dr. Robert Bailey, U.S. Forest
Service, Ogden, Utah.
Prepared under Interagency Agreement No. EPA-IAG-D6-0660 with the
Environmental Research Laboratory, Office of Research and Development, U.S.
Environmental Protection Agency, Athens, Georgia 30605. Project officers were
Lee Mulkey, ORD, EPA, Athens, Georgia 30605, and Michael A. Barton, USDA,
Forest Service, Washington, D.C. 20250.
NOVEMBER 1977
FOREST SERVICE I O \ OFFICE OF RESEARCH AND DEVELOPMENT
U.S. DEPARTMENT OF AGRICULTURE 15S2Z ' ENV(R0NMENTAL PROTECTION AGENCY
%«o^c"
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DISCLAIMER
This report has been reviewed by the Environmental Research Laboratory,
Athens, Georgia, U.S. Environmental Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily reflect
the views and policles of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or
recommendation for use.
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FOREWORD
Environmental protection efforts are increasingly directed towards
preventing adverse health and ecological effects associated with secific
compounds of natural or human origin. As part of the Laboratory's research on
the occurrence, movement, transformation, impact, and control of environmental
contaminants, "fhe Techn6logy Development and Applications Branch develops
management or engineering tools for assessing and controlling adverse
environmental effects of non-irrigated agriculture and of silviculture.
SiIvicultural activities that disturb surface soil and cause accelerated
rates of erosion are associated with increased sediment loads that adversely
affect water quality in a watershed. This report assesses the erosion
potential of common si IvicuItural practices and provides a method to identify
costs related to the.control of this non-point source of pollution as an aid
to forestry managers and water quality planners.
David W. Duttweiler
Director
Environmental Research Laboratory
Athens, Georgia
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PREFACE
The passage of the Water Pollution Control Act Ammendments of 1972
requires that actions be taken to control sources of pollution that affect the
nation's waters. One of the areas of concern is the pollution resulting from
non-point sources. Non-point source pollution arises from several categories
of land use, one of which includes si Ivicultural activities. Within this
category, a major concern is the water quality changes associated with
sedimentation that can result when si IvicuItural activity disturbs the surface
soil and causes accelerated rates of soil erosion.
In order to formulate non-point pollution control strategies and plans,
it is necessary that the water quality planner be able to recognize the
potentials for pollution associated with specific activities. The planner
must also be able to identify the costs of controlling the sources of
pollution and place these costs in perspective.
This report stems from these two basic requirements:
.A broad level assessment of the erosion potential associated with
common si IvicuItural activities on a nation-wide basis;
.A methodology to identify costs associated with erosion control in
order to conduct a cost-effectiveness analysis of erosion control
practices.
The assessment of erosion potential is intended to facilitate the
identification of potential erosion problems associated with commonly used
si Ivicultural activities. This is presented as a series of regionalized
tables. The tables describe the commonly applied siIvicultural activities and
rank them relative to erosion potential.
i v
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The method for cost-effectiveness analysis is presented by discussing the
basic concepts of cost-effectiveness analysis and their application to erosion
control problems. Examples are provided that illustrate applications of the
method.
The non-point pollution phenomenon is extremely complex and to fully
describe the relationship between erosion and water quality is beyond the
scope of this report. The report is intended to present information that is
useful for gaining a perspective on the erosion potential of si Ivicultural
activities and to describe a method that can be used for cost-effectiveness
analysis of erosion control practices.
The user of this report must recognize that the erosion potential
assessment is not intended to be used as a mandate for change in si Ivicultural
practices or as the specification of site-specific "Best Management
Practices." Because of the broad nature of the assessment, much of the
site-specific siIvicultural information about erosion potential is lost in the
aggregation.
The cost-effectiveness methodology relies on input data that are external
to this report. The subject data are dependent on highly variable
environmental and operational conditions and must be supplied by competent
technicians. The method assumes that the precision of the input data is
compatible with erosion control goals. It further assumes that the goals are
known and that the costs associated with erosion control are at least equal to
the benefits.
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ABSTRACT
This report focuses upon erosion that contributes to non-point source
pollution occurring in forested environments as a result of si IvicuItural
activities. Specifically, the document discusses three topics: (1)
si IvicuIturaI practices that are currently being applied throughoijt the United
States, with indications of how these practices may affect the rqte of
erosion, (2) a method for determining the cost-effect Ivenes^ of erosion
controls that could mitigate or prevent the adverse effects of si 1vicuItural
practices, and (3) examples applying the described method for economic
analysis using information presented in (1). The informatlpn and outlined
method are Intended for forest managers and water quality planners to enhance
analysis and improve decisions concerning the reduction of non^polnt pollution
probI ems.
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CONTENTS
Foreword i i i
Preface iv
Abstract vi
Figures viii
Tables ix
1 . Introduction 1
2. Si IvicuItural Practice and Erosion Potentials 6
3. Basic Concepts of Cost-Effectiveness Analysis 27
Define objectives 31
Establish alternatives 31
Assessment of effectiveness and costs 32
Analysis 44
Conclusion 50
4. Applications of Cost-Effectiveness Analysis 53
Review of the steps 55
Example 1: Cost-effective analysis applied to control
selection on a single site 63
Example 2: Choice of preventive erosion control for mechanical
site preparation in the South 83
Example 3: Large area analysis 87
References 103
Bibliography 105
Glossary • . . 107
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FIGURES
Number Page
1 Report contents compared with management objectives 2
2 Ecoregion 2100: humid warm-summer continental
(Lake States and Northeast) 11
3 Ecoregion M2100: humid warm-summer continental
(Columbia forest) 14
4 Ecoregion 2200: humid hot-summer continental . . 16
5 Ecoregion 2300: humid subtropical 18
6 Ecoregion 2400: humid maritime 20
7 Ecoregion 2600: mediterranean 22
8 Ecoregion 3100: semi arid steppe 24
9 Ecoregion 2500: prairie 26
10 Relationship of cost-effective analysis to
resource allocation and decision-making 29
11 A simple cost-effectiveness model 45
12 An illustrative example of the tabular display 46
13 An illustration of a choice criterion 48
14 Cost-effectiveness flowchart 53
15 Cross section of a roadbed 64
16 Total cost for erosion control for access activities 76
17 Total cost curves for all activities 79
18 Total cost for erosion control 81
19 Tabular display 86
20 Program costs 102
VIII
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TABLES
Number Page
1 Classification of Control Methods, with Examples 4
2 Major SiIvicuIturaI Activities and Access Practices
in Ecoregion 2100 (Lake States and Northeast) 12
3 Major Si IvicuIturaI Activities and Access Practices
in Ecoregion M2100 (Columbia Forest). ... 15
4 Major SiIvicuItura I Activities and Access Practices
In Ecoregion 2200 17
5 Major SiIvicuItura I Activities and Access Practices
In Ecoregion 2300 19
6 Major Si I vicuItura I Activities and Access Practices
In Ecoregion 2400 21
7 Major SiIvicuItura I Activities and Access Practices
In Ecoregion 2600 23
8 Major Si IvicuIturaI Activities and Access Practices
In Ecoregion 3100 25
9 Estimated Erosion from Source Areas 65
10 Erosion Control Alternatives 66
11 Total System Effectiveness of Controls 68
12 A Standard Accounting Framework Applied to Control 11 70
13 Multi-period Costs Attributable to Erosion Control
for Water Pollution Abatement 71
14 Summary of Erosion Control Alternatives 73
15 Total Costs of Erosion Control for Access Activities 75
16 Cost-Effectiveness Alternatives for All Forms of
Erosion Control 78
17 Total Cost Relationship to Effectiveness Levels 80
18 Regional Stratification 88
i x
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19 Erosion Control Strategies 90
20 System Effectiveness of Strategies 91
21 Total Costs for Region 93
22 Summary of Alternative Strategies 94
23 Marginal Analysis 97
24 Alternatives Ranking 99
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CHAPTER 1
INTRODUCTION
This report is intended to be a tool for both water quality planners and
forest land managers who deal with the problem of non-point source pollution,
and more specifically, erosion as an indicator of pollution. Clearly,
management goals may vary widely among users of this report. Forest managers,
for example, have a set of goals that extend beyond the control of non-point
water pollution; water quality planners, on the other hand, may be directing
their attention solely upon pollution abatement. In either case, this report
is intended to serve both classes of users although emphasis is placed on
pollution abatement to the diminution of other goals.
Figure 1 shows how the contents of this report interface with overall
management strategies. It furnishes information which when integrated with
overall objectives in management provides a perspective on the role of erosion
control. Once this integration has been achieved, a method for cost-
effectiveness analysis is provided as a tool to assist in attaining the
objectives.
There are three objectives for this report. This report: (1) broadly
summarizes current si Ivicultural practices in the United States; (2) indicates
the erosion potentials associated with these practices; and (3) presents an
economic model (cost-effectiveness) for determining the most appropriate
controls for reducing erosion.
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Non-point pollution aspects
of silvicultural management
Erosion
potential
Silvicultural
activities
Contents of this report
Information
Management
objectives in-
cluding erosion
reduction
Erosion
hazards
Alternative
mitigative or
preventive
controls
Perspective
Cost-
effective-
ness
analysis
Decision tool
Most probable
conditions
without erosion
control
Reduced
erosion
impact
Figure 1, Report contents compared with management objectives.
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(1 ) Si IvicuIturaI systems (including access practices) as they are
currently applied throughout the United States are summarized (see Tables 2
through 8). This is not a presentation or implication of "best management
practices." The purpose is simply to transfer information to the user which
will sensitize him to the current operational techniques of si IvicuItural
management. It is broadly based and describes these activities by region
while maintaining a national perspective.
(2) Si Ivicultural activities, including access practices, currently
applied are evaluated to assist planners In Identifying erosion potentials.
The evaluation Involves ranking the activities that could contribute to
non-point pollution (see Tables 2 through 8). Wide diversity exists in the
expertise with which these activities are formulated and carried out as well
as the environmental conditions within which forest managers operate. The
evaluations reflect these variables.
The report deals with silviculture in its broadest sense: the art and
science of cultivating forest crops and the establishment and growth of
forests. Activities pertinent to silviculture—harvesting practices, logging
systems, slash disposal, Intermediate cultural treatments, and the
establishment of access—are discussed, as are the major si IvicuIturaI
systems—clearcut, seed tree, shelterwood and selection. (Refer to the
glossary for extended discussions of these important terms.)
Each of the si Ivicultural systems and the activities related to them
interface with the natural environment in ways that could result In non-point
pollution from accelerated erosion and mass wasting. Cutting intensities,
understory and soil disturbances, and time Intervals between activities on a
site are major factors influencing the rate of soil loss. However,
sllvlcultural practices can be amended by altering the quantity, nature, or
time of the erosion phenomena and thus contribute to non-point pollution
reductIon.
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Controls can be described as "preventive" or "mitigative" according to
the mode of application. Preventive controls apply to the pre-implementation
phase of an operation. These controls involve stopping or changing the
activity before the soiI-disturbing activity has a chance to occur.
Mitigative controls include vegetative or chemical measures or physical
structures which alter the response of the soil disturbing activity after it
has occurred. Table 1 illustrates some of the major characteristics of the
two types of controls and provides some examples.
TABLE 1. CLASSIFICATION OF CONTROL METHODS WITH EXAMPLES
Mitigative
Preventive
A. Surface protection:
1. Access: Seeding, mulching,
riprap, or mat on cut-and-fill
slopes
2. Timber harvest: Maintenance of
vegetative cover; distribution
of slash
3. Cultural treatments: Seeding;
planting; fertilization
B. Flow diversion and energy:
1. Access: Berms above cut
slopes; benches on cut slopes;
checkdams in ditches; drop
structure at culvert ends;
water bars on road surface;
flow diversion from potential
mass failures or at mid-slope
2. Timber harvest: Buffer strips;
water bars on skid trails
3. Cultural practices: Plowing,
furrowing, bedding
C. Access design modification
A. System design and maintenance
1. Access: Minimize cuts and
fills, roadway widths and
slopes; control road density
2. Timber harvest: Minimize soil
compaction from equipment
operation; use site-compatible
log removal system; control
harvested volume within a
watershed; limit harvest on
unstable slopes
3. Cultural treatments: Minimize
re-entry disturbances; fire
control
B. Timing:
1. Access: Closure of temporary
roads; limited access; closure
during adverse conditions
2. Timber harvest: Limit
operation during adverse
climatic conditions; site
preparations during favorable
conditions
3. Cultural treatments: Inten-
sive and number of thinnings
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(3) A final objective is to present a method for economic evaluation.
Several choices may be available for preventing or mitigating erosion. The
question then becomes: Which of these is "best"? Cost-effectiveness analysis
is provided as one solution to the problem.
The following chapters have been developed to meet the three objectives
stated above. Chapter 2 contains information describing current si IvicuItural
practices found throughout the country; erosion potentials these activities
entail are also described. The chapter is intended primarily as a source of
information to planners and managers, both as a description of erosion-related
si IvicuItural activites and as a information reference for persons conducting
a cost-effectiveness analysis of erosion controls.
Chapter 3 presents basic concepts underlying cost-effectiveness analysis,
with emphasis upon applications of the method to erosion-reduction problems in
silviculture. A definition for cost-effectiveness analysis and a comparison
with other forms of economic analysis are presented initially. Following this
is a step-by-step discussion of the method used to conduct a cost-effective-
ness analysis. This chapter should serve both as an introduction to cost-
effectiveness analysis for the novice and as a reference to those conducting a
current analysis.
The last chapter illustrates procedures for applying cost-effectiveness
analysis to erosion problems in silviculture. It begins with a review of the
major steps in the method, along with major information requirements and
suggested information sources. Following this, examples are presented that
illustrate cost-effectiveness analysis in different situations. Reference is
made to information presented in Chapter 2.
Finally, glossary and literature cited sections are presented. The
glossary contains definition to words and phrases used throughout the text.
The literature cited section contains references to the major source documents
referred to in the preparation of the text.
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CHAPTER 2
SILVI CULTURAL PRACTICES AND EROSION POTENTIALS
Erosion is a natural phenomenon. It is the process which gradually
removes soil and rock from a site by various agents Including wind and water;
In the case of mass wasting, gravity is the major agent. The rate of erosion
is the consequence of physical site characteristics, biotlc features and the
hydrologic cycle. These include the type of soil materials, topography,
macro- and micro-climatic conditions and the density and distribution of
vegetation. The observed rate of erosion results from the Interaction of all
these factors.
Man's activities often disrupt this complex interaction. In the case of
silviculture, this might occur by removing the protective cover of trees, thus
exposing the forest floor to the erosive energy of precipitation. Two related
but distinct concepts need to be discussed In terms of surface erosion—
erosion potential and erosion hazard. Both are pertinent to evaluating
si Ivlcultural management systems.
Erosion hazard Is directly associated with physical site characteristics.
Energy from radiation, precipitation, gravity or flowing water provides the
effective force for erosive action. In forested environments energy Inputs
are dissipated by the vegetative cover or the litter layer, for example. The
degree to which a site could respond, In the absence of these modifying agents
can be viewed as the erosion hazard. The erosion potential is the extent to
which management activities affect the modifying factors or site
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characteristics themselves. Thus, erosion hazard is an inherent property of
the site while erosion potential relates to the effect of siIvicuItural
activities upon that site.
It becomes clear that the relationships between rate of erosion and
siIvicuItural activities are complex and depend upon various environmental
conditions and the extent or Intensity of si Ivicultural actions. In the
following discussion attention is focused on erosion hazard in a regional
context and erosion potential in terms of various activities.
Relating the various environments occurring throughout the United States
to siIvlcultural management requires an aggregation of information to a
manageable scale. Such Information has been prepared by Bailey (1976) in the
form of a map which organizes and interprets inventories of the Nation's lands
and resources, taking into account both biotlc (flora and fauna) and abiotic
(climate, soils and land-surface form) factors. The map delineates
"ecoreglons" which are similar with respect to broad ranges of environmental
parameters. Bailey's format provides a convenient basis for discussing both
erosion potential and erosion hazard, for identifying vegetation types, and
for discussing related siIvlcultural activities.
The ecoreglon descriptions appearing on the map pages have been largely
adapted from Bailey's classifications that appear in Ecoreglon Descriptions
(To Accompany Map of Ecoregions of the United States) (in press). Some areas
In the continental United States were not characterized (the Mojave-Sonoran
desert south of the Rocky Mountains, for example) because little or no
siIvlcultural activity takes place. Descriptions of some factors (fauna, for
example) that Bailey considers were not Included, again because they are not
directly pertinent to a discussion of non-point pollution abatement, or to
sMvicultural activities In general.
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The use of ecoregions or the ecoregion system does not imply that this is
the only applicable land classification system. Bailey's ecoregion system is
relatively new and largely untested in an operational sense. However, since
erosion response to siIvicultural activities arises from the complex
interaction of many environmental factors, it was concluded that a
classification system that encompasses this concept should be employed.
The remainder of this chgpter is structured around seven major ecoregions.
Each is discussed separately. Included is a map which delineates the areal
extent of the ecoregion together with a brief narrative describing the major
characteristics related to the environment and silviculture.
In addition to the map and its narrative, a table is presented which
relates each major siIvicultural type within the ecoregion to harvesting
paractice, logging system, slash disposal, intermediate cultural treatment,
and access. Each element of the array contains a brief summary of the
individual practices which are currently being employed. For example, the
currently applied methods for slash disposal in the white pine type would be
noted, along with an indication of the frequency or generality of use. The
information contained here is not intended to be prescriptive, but reflects
the current situation. Little siIvicultural activity occurs in Ecoregion
2500. For this reason, no table for Major SiIvicultural Activities and Access
Practices in Ecoregion 2500 has been includgd. Refer to adjacent areas for
required information.
Access activities are only indirectly related to specific forest types.
However since these activities are closely correlated with geographic
characteristics and harvesting activities/cultural treatments, a discussion of
common access practices typical of the ecoregion itself is included in each
table.
A summary of siIvicultural techniques is presented at the bottom of the
table to provide a short review of the information contained above. Major
activities are emphasized.
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The principal basis for presenting the information on current
si IvicuItural methods is to indicate where problems of erosion might arise,
not to identify "best management practices." This objective is accomplished
by using a scale which indicates the relative severity of erosion potential
for these activities. Silviculture activities are ranked relative to
themselves, not in comparison to other erosion-causing activities like
construction or agriculture, for instance. Similarly, the indications for
erosion potentials relate to the ecoregion only—not to comparisons between
ecoregions. Dark green highlighting is used to signify an activity or
practice that could present significant erosion problems; light green
highlighting denotes a somewhat lower or moderate potential. The lack of
color highlighting is an indication that little or no erosion potential should
generally be expected.
The purpose of this technique is to emphasize where problems couId arise
in the application of si IvicuItural management, rather than to indicate where
problems presently occur. Similarly, specification of high erosion potential
for an activity does not preclude the opportunity for mitigation to the extent
that the activity may have little or no erosion impact. The inherent
variability of environmental conditions within any ecoregion is large.
Combined with the range of alternative management strategies which can alter
these conditions, the task of producing a quantitative, objective estimate of
erosion impacts is substantial—especially at the indicated geographic scale.
The reader must not reach unwarranted conclusions from the information
presented on erosion potentials. For example, clearcutting is often rated as
having a relatively high erosion potential when compared with selection
cutting. The conclusion that selection should be preferred over clearcutting
as an erosion reduction practice need not follow. There are other factors to
take into account. For example, the regeneration prescription for the desired
forest type may require even-aged management as opposed to uneven-aged.
Second, when considered with other management goals, the harvest system should
be economically efficient—just as clearcutting often is. Third, openings
caused by smaller clearcuts or selection cuttings may require a more extensive
road network—often identified as a major source of erosion. Trade-offs
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between reduced harvest impact and access impacts must be included in the
evaluation. In perspective, the erosion potential specification is only to
identify and focus on possible problems rather than mandate changes in
management.
The premise for evaluating the various activities in terms of the
potential scale included a number of factors: Field surveys were conducted to
sample activities in each ecoregion. Forestry researchers from both private
industries and public agencies were consulted for information about current
practices and problem areas. As a result, the scaling is a reflection of
judgment based on present knowledge and the expertise of many individuals.
A detailed literature search on the state-of-the-art status of
si IvicuIturalIy-related erosion knowledge was not conducted due to the
existence of several current sources (for example, the EPA reports, Forest
Harvest, Residue Treatment, Reforestation & Protection of Water Quality. 1976
and Non-point Water Quality Modeling in Wildland Management; A
State-of-the-Art Assessment (Volume I—Text) 1977.
A concluding paragraph is presented at the bottom of each table which
reviews erosion potentials that arise from si IvicuItural management in each
ecoregion. This review discusses the major practices which contribute to
erosion potentials and indicates the individual activities that contribute to
the rating. Again, this information comes from a diversity of sources.
To provide quantitative assessments of wh ich si IvicuIturaI operations
create greater erosion potentials is beyond both the purpose and scope of this
report. Most erosion potentials created by si IvicuItural operations are
site-specific and should be dealt with on a site-specific basis. When applied
to specific situations, general rules will frequently be unworkable, ineffec-
tive, or both. Hence, this report is not intended to present blueprints, but
to identify problems. Solutions to these problems will require the planner
and forest manager to apply their experience and ingenuity to ^peci flc si teg.
10
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M 2100
Figure 2. Ecoregion 2100 (After Bailey 1976).
HUMID WARM-SUMMER CONTINENTAL (LAKE STATES AND NORTHEAST)
This region occupies about 367,800 square miles, or 11.1 percent, of the total land mass in the United States.
Most of the area has low relief, but rolling hills and low mountains occur in many places. Lakes, poorly drained
depressions, morainic hills, outwash plains, and other glacial features are characteristic as a result of Pleistocene
glaciation. Elevations range from sea level to 4,000 feet with a few isolated peaks of more than 5,000 feet.
Polar continental air masses on the north and maritime or continental tropical air masses on the south create
strong seasonal temperature contrasts. There are four to eight months of over 50° F. The warm summer has an average
temperature in which the warmest month is below 71.6° F. Rainfall is ample at all times, but distinctly greater during the
summer.
Soils vary greatly from place to place and include peat, rrtarl, clay, silt, sand, gravel, boulders and various
combinations of these materials. Alfisols and Spodosols (Podzols) are strongly leached but with an upper layer of
humus. Cool temperatures inhibit bacterial activity which would normally destroy organic matter in tropical regions;
these soils are deficient in calcium, potassium, and magnesium and are, in general, acid in chemical nature. These are
not highly productive for crop farming, but well suited to the growth of conifers.
Conifer and mixed conifer deciduous forest extend throughout the ecoregion. Vegetation is characterized as
"transitional" between the boreal forest and deciduous forest zone. Forests are made up of either mixed stands of a few
coniferous species, or an arrangement in which pure deciduous forest exists where there is a favorable habitat and
good soils, and pure coniferous forest exist on less favorable habitats with poor soils.
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M 2100
Figure 3. Ecoregion M2100 (After Bailey 1976).
HUMID WARM-SUMMER CONTINENTAL (COLUMBIA FOREST)
The Columbia forest occupies about 45.300 square miles, or 1.4 percent, of the total land mass in the United
States. It consists of steep rugged mountains which rise to over 9,000 feet and have local relief in excess of 3,000 feet.
Most of the region has been glaciated.
This ecoregion is characterized as a "highland" province, separate from that of Ecoregion 2100 (Lake States and
Northeast) It represents a special problem in classification in that, as with all mountain regions, the middle and upper
slopes do nofhave the same climate as their adjacent lowlands; however, they do have the same climatic regime as the
lowlands. In this particular warm-summer continental region having a humid climatic regime, valley bottoms are
humid and the montane zone is the lowest zone present. The coldest month is below 32°F and warmest is below
71.6° F. Rainfall is adequate throughout the year, but summer tends to be dry because Westerly air masses bring the
summer dry climate of the Pacific Coast inland across the area. Theeffect is a distinct climatic grad ient from both north
to south and east to west.
Soils are Alfisols, Spodosols, and Inceptisols. A variety of igneous, sedimentary and metamorphic rocks form
mountain masses. In comparison with other parts of the Rocky Mountains, however, shallowness and stoniness of
soils play a relatively minor part in forest distribution. In the foothills of the Rockies and to the south of the glacial
borders, loess and volcanic ash have been deposited on the slopes, thus helping to form the soils.
Effect of the climatic gradient in this region is reflected in both the flora and vegetation types. Mixed coniferous-
deciduous forest predominates, with Douglas-fir forest and cedar-hemlock-Douglas-fir forest being the major forest
types.
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M 2100
Figure 4. Ecoregion 2200 (After Bailey 1976).
HUMID HOT-SUMMER CONTINENTAL
This region occupies about 367,800 square miles, or 11.1 percent of the total land mass in the United States. The
land-surface form in this region is rolling, though some parts are nearly flat; in the Appalachian Mountains there is high
relief up to 3,000 feet. The northern areas have been glaciated, but not the southern.
This ecoregion shares the same characteristics as Ecoregion 2100 except it is more moderate with a strong
annual temperature cycle and cold winters and a hot summer; the warmest month is above 71.6°F. Precipitation is
markedly greater in summer months. Because temperatures are warm, the soils are rich in humus and moderately
leached.
Soils are Alifsols, Spodosols and Inceptisols. They are rich in humus and moderately leached as to have a
distinct, light-colored leached zone.
Forest vegetation is deciduous, with a dense canopy in summerwhich produces a thick litter layer. Lower layers
of small trees and shrubs are not well developed. Common trees of the deciduous forests are oak, beech, birch,
hickory, walnut, maple, basswood, elm, ash, tulip tree, sweet chestnut and hornbean. In the more poorly drained
habitats, the deciduous forest consists of such trees as alder, willow, ash and elm and many shrubs. Pines readily
develop as second-growth vegetation where the forests have been cleared.
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Figures. Ecoregion 2300 (After Bailey 1976).
HUMID SUBTROPICAL
This region occupies about 408,000 square miles, or 12.3 percent, of the total land mass in the Un ited States. It is
characterized largely by low relief (less than 300 feet), but some parts are gently rolling. In the lower coastal plains the
streams are sluggish; in the upper coastal plains, they range from swift to turbulent. In some areas, there are many
marshes and swamps.
This area is characterized as a temperate rainy climate with hot summers. The average temperature of the
warmest month is over 71.6°F. Rainfall is ample, but distinctly greater during the summer; even the driest summer
month receives more than 1.2 inches of rain. Thunderstorms are especially frequent in the summer.
Soils of the moister, warmer parts of the region are strongly leached red-yellow soils related to the Oxisols and
Ultisols (Latosols) of the humid tropical and equatorial climates. Rich in iron and aluminum oxides, these soils are poor
in many plant nutrients essential for successful agricultural production. Soils of the cooler parts of the region are
similar to those found in Ecoregion 2200 (Alfisols, Podosols).
Vegetation of the outer coastal plain, is characterized by temperate pine, pine-hardwood, hardwood and
wetland forests. There are also large areas of loblolly and slash pines and bald-cypress, butthisvegetation represents
forms in excessively dry or wet habitats. The climax vegetation is conifer-oak forest. There is a well developed strata of
vegetation that in different places may include mosses, ferns, palms, shrubs and herbs. The inland area is
characterized by summer green deciduous forest like that described in Ecoregion 2200.
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Figure 6. Ecoregion 2400 (After Bailey 1976).
HUMID MARITIME
This region occupies about 76,000 square miles, or 2.5 percent, of the total land mass in the United States. It
consists of a series of steep, rugged mountains, but in places there is a narrow coastal plain. Mountains along the coast
rise to 5.000 feet above sea level and have local relief of 1,000 to 3,000 feet. The interior Cascade Range consists of high
mountains 8.000 to 9.000 feet in altitude, surmounted at intervals of 5 to 85 miles by volcanoes of much higher
elevation. Much of the region has been glaciated, especially in the northern portion.
This maritime West Coast climate is characterized as rainy with warm summers. Average temperature of the
warmest month is under 71.6° F, but at least four months average 50° F or more. Precipitation is considerable (30 to 150
inches or more) but is well distributed throughout the year, although there is a distinct reduction during summer
months. Cooler air temperatures reduce evaporation and produce a very damp, humid climate with much cloud cover.
The small annual temperature range makes for mild winters and relatively cool summers.
Soils of this climate are the Alfisols, Spodosols, and Inceptisols; they are of a strongly leached type and acid in
nature. Bacterial activity is slow because of the cool temperature, and organic matter is not consumed readily, forming
conifer surface deposits. Bases are removed because organic acids from decomposing vegetation react with soil
compounds.
These dense conifer forests are primarily montane in character. Douglas-fir, western hemlock, western red
cedar, and spruce grow on the coastal ranges of the Pacific northwest. Shrubs of many kinds are well developed in and
around the forest. x
The humid conifer forest changes in southwestern Oregon due to the fact that amabilis fir is replaced by
redwood. In northwestern California, redwood is the characteristic tree of the fog belt. Associated with it are Douglas-
fir and other conifers. These are perhaps the densest of all coniferous forests, with the world's tallest trees. In the
higher mountains a well marked subalpine belt is present.
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Figure 7. Ecoregion 2600 (After Bailey 1976).
MEDITERRANEAN
The topography of this region is greatly varied, for it includes the Coast Range along the Pacific Ocean, the
plains of the central valley of California, and the glaciated Sierra Nevada range Elevation ranges from sea level to over
14,000 feet. This region occupies about 86,300 square miles, or 2.7 percent, of the total land mass of the United States.
This area is subject to alternate wet and dry seasons because it is located in the transition zone between the dry,
West Coast desert and the wet, West Coast climate. It is characterized as a temperate, rainy climate with dry, hot
summers and summer droughts.
Soils of this climate are not readily subject to classification. Reddish chestnut (Alfisols, Mollisols) and reddish
brown soils (Aridisols), typical of the semiarid climate, are present.
The presence of a wet winter and a dry summer is unique among climate types and results in distinctive natural
vegetation of hardleafed evergreen trees and shrubs — sclerophyll forest. Various forms of sclerophyll woodland and
shrub are also typical. The vegetation must be able to withstand severe summer drought. Ecologic zones are
exceptionally well marked. Grassland covers the floor of the larger valleys; a zone of oaks and chaparral occupies the
hills and lower mountains; the montane and subalpine belts together include conifer forests of the higher mountains;
and the alpine zone is the treeless area above timberline.
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Figures. Ecoregion 3100 (After Bailey 1976).
SEMIARID STEPPE
This ecoregion occupies about 911,200 square miles, or 27 9 percent, of the total land mass in the United States
It is characterized by flat and rolling plains, tablelands of moderate to considerable relief, high elevation plateaus.
interior basins, high rugged, glaciated mountains rising steeply from semiarid plains, mtermontane depression having
floors less than 6,000 feet in altitude, and volcanic mountains
This region is associated with a semiarid continental climate regime in which, despite a summer rainfall
maximum, evaporation exceeds precipitation on the average. The steppe is a transitional belt surrounding the desert
and separating it from humid climates beyond. Winters are cold and dry; summers warm to hot. In mountainous areas,
precipitation in winter is greater than in the plains areas
Soils of this region are dominantly Mollisols, Aridisols and Alfisols, but timbered areas have many Inceptisols
(Brown Forest, Gray-Brown Podzolic, Chernozem). The dominant soil process in this area is calcification, with
salinization on the poorly drained soils. Humus content is relatively sparce wherever vegetation is sparse Soils often
contain an excess of precipitated calcium carbonate and are very rich in bases
There are all gradations of vegetation into both semidesert and woodland varieties In the plamsareas are many
species of short, bunched, prairie grasses (including alkali-tolerant ones), scattered xerophtic shrubs (sagebrush, for
example) ana low trees. Ground coverage may be small and much bare soil exposed Mountainous areas are
characterized as alpine tundra; trees absent In the subalpine area. Englemann spruce and subalpine fir predominate,
with aspen and lodgepole pine. In the montane areas are ponderosa pine and Douglas-fir
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Figure 9. Ecoregion 2500 (After Bailey 1976).
PRAIRIE
The North American Prairie consists of smooth to undulating plains with low relief (less than 300 feet), but some
areas are hilly. Elevation ranges from sea level to 2,000 feet. The northern part has been glaciated. Theecoregion
occupies about 511,000 square miles, or about 15.5 percent, of the total land mass in the United States.
This area lies on the more arid western side of the humid continental climates, and with decreasing latitude
extends over into subtropical climates. The temperature characteristic of the climate corresponds to those of adjacent
humid climates. However, in summer air and soil temperatures are high, so that on uplands, soil moisture is not
adequate for tree growth, and deeper water sources are beyond the reach of tree roots.
Soils of this region are Mollisols and Alfisols (Chernozem, Chestnut and Brown soils). The soil process
associated with prairie vegetation is calcification and results in soil profiles characterized by thick, dark-brown A and 8
horizons. Grass roots penetrate these soils deeply Bases brought to the surface by plant growth are released upon the
surface and restored to the soil, thus perpetuating soil fertility.
The natural vegetation of the prairie consists of tall grasses comprising the dominant herbs, and subdominant
(orbs (broad-leaved herbs). Trees and shrubs are almost totally absent but may occur in valley or other topographic
depressions as forest or woodland patches.2
2This ecoregion has not been characterized by silvicultural type, and therefore it has no ecoregion table that
accompanies it. For a discussion of silvicultural types that do occur in this ecoregion, see the appropriate ecoregion
tables.
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CHAPTER 3
BASIC CONCEPTS OF COST-EFFECTIVENESS ANALYSIS
The objective of this chapter Is to outline the basic concepts of
cost-effectiveness analysis. These concepts form the general method for
conducting an analysis. Individual applications of the method may require
more detailed and rigorous procedures to fit specific characteristics of any
single analysis.
Cost-effectiveness analysis Is an economic model that applies to specific
types of problems and can be used In decision-making. The proper context for
applying It, and the inputs (I.e., measures of effectiveness and costs), are
the essentials for successful application of the model.
The use of cost-effectiveness analysis assumes that there are alternative
ways of reaching an objective, each alternative requiring certain resources
and producing certain results (ARINC Research Corporation 1970). A key
characteristic of cost-effectiveness analysis is that the objective can be
reached by more than one single system or program. Thus, the purpose of the
analysis Is to determine the "best" system or program for meeting the
objective.
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An example will illustrate these ideas more fully. Suppose a forest
manager is charged with developing a program to reduce non-point source
pollution from erosion caused by si Ivicultural activities. The objective is
erosion reduction; and the manager has several options for meeting it,
including the choice of harvest system, equipment employed, intensity of
management, etc. Cost-effectiveness analysis will provide him a model to deal
with evaluation of those options contributing to meeting the goal.
Specific conditions for using cost-effectiveness analysis need to be
discussed.
First, this kind of analysis is an attempt to mjnimize dollar costs
subject to a performance requirement (which may or may not be measurable in
dollar terms) or, conversely, to maximize some measure of output subject to a
budget constraint (Washington Operations Research Council 1967). A conclusion
that could be drawn is that cost-effectiveness analysis can result in economic
suboptimlzation; that is, because the analysis deals only with cost and not
the relationship between cost and revenues, there is no basis for evaluating
the efficiency of the solution.
In the case of non-point source erosion controls, cost-effectiveness
analysis can be used to examine alternative sets of controls to determine a
"least-cost" solution subject to a performance standard. The emphasis is
placed upon the relationship between the value of resource inputs (outlays or
opportunity costs) and the indicators of program outputs (effectiveness). The
benefit or revenue ledger plays a subordinate role, especially with regard to
external benefits or alternate operating scales, because these benefits are
either unquantif lable or only indirectly quantifiable in the context of a
single unit of measure (e.g., dollars).
This does not mean that benefits may not exist. Implementation of
pollution abatement may result in management changes which improve
productivity or increase regional income, for example. The point is that
cost-effectiveness analysis deals only with changes in input costs and output
performance, not costs and benefits which, when evaluated using models like
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benefit-cost or internal rate of return, provide information relating to
economic efficiency. Further, it would be incorrect to concjudg that the pet
cost of pollution abatement Is equal to the cost of Input resources as used in
the cost-effectiveness model.
Second, cost-effectiveness analysis is not resource allocation, which is
concerned with the allocation of resources (time, manpower, money, etc.) among
competing uses. The distinction is illustrated in Figure 10.
SELECTION OF
BEST SYSTEMS
FOR INCORPORATION
INTO
RESOURCE ALLOCATION
RESOURCE
ALLOCATION
COST-
EFFECTIVENESS
ANALYSIS
SPHERE OF
-DECISION-MAKING
Figure 10. Relationship of cost-effectiveness analysis to resource
allocation and decision making (after Kazanowski 1968, p. 117).
To continue the discussion of the forest manager, if his objective is to
determine the extent to which he should concentrate his resources on erosion
control as opposed to thermal problems (as well as reducing non-point water
pollution In general) he has moved from the area of cost-effectiveness
analysis to resource allocation.
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These are separate kinds of analyses applied to different situations.
However, in some Instances the two analyses can be used in conjunction, as
schematically shown in the figure above. In this case the decision might
Include the determination of the best erosion control strategy (cost-
effectiveness analysis) in light of the total program for water pollution
reduction (resource analysis).
In summary, cost-effectiveness analysis is an effective model for
economic analysis of alternative erosion controls for si IvicuItural activities
given the following conditions:
1. There Is a specified performance level (erosion reduction standard)
set as a goal toward which the effectiveness of a control can be measured.
Cost-effectiveness analysis is predicated on the specification of this goal.
2. The benefits of erosion control arise largely from preventing
off-site diseconomies or externalities relative to si IvicuItural objectives
and are characteristically "public goods." These benefits (monetary or
Intangible) are Implicitly assumed to be valued by society at least as much
as the cost of the control and are not explicitly enumerated.
3. The unit for siIvicuItural management has a specified level of output
(wood products, for example) measured as revenues or benefits. Since cost-
effectiveness analysis deals only with costs, the benefit side (in terms of
production) must remain relatively fixed as a point of reference during
analysis.
4. The focus of attention is on the changes In cost of controlling
erosion to Improve water quality and the relationship between resource inputs
and output performance, not on the economic efficiency of the entire
operation.
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The method for cost-effectiveness analysis Involves a set of activities
performed in sequence; its execution Is a process. Following is a description
of each of the steps In the process in the order they generally occur although
the Idiosyncrasies of any Individual application may alter the sequence.
STEP 1. DEFINE OBJECTIVES
Identification of goals and definition of objectives Is the most
Important aspect of any analysis. Problem Identification is critical to
defining the appropriate tool for analysis. Although specific objectives of
cost-effectiveness analysis of erosion controls may vary with alternate
applications of the model, the basic objective can be stated as—meeting a
specified level of erosion control for non-point pollution abatement in a
least-cost manner. The minimum level of effectiveness Is generally assumed to
be an expression of a standard.
STEP 2. ESTABLISH ALTERNATIVES
The second step entails determination of feasible erosion control
strategies. This Is a process of integrating the objectives of si Ivicultural
management with the response by the site via Its biological and physical
attributes, and the available mitigative or preventive techniques for
controlling erosion. Each of these conceptual strategies should meet or
exceed the erosion control objective.
A meaningful comparison of alternatives requires the strategies to
be significantly dlsslmilar so that a cost-effectiveness evaluation Is
warranted. Slight variations are not necessarily separate alternatives.
Developing alternatives often calls for novel or innovative ideas, and In many
cases an erosion control strategy will consist of a number of Individual
control practices. When comparing two such strategies composed of many of the
same controls, focus should be on the cost-effectiveness of the dlfferences
between the two, with the similar aspects taken as equal and, therefore, not
constituting a basis for making a decision.
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The feasibility of various erosion controls frequently depends upon the
scale of operation, the stage of the operation, and environmental conditions.
For example, small scale si IvicuItural operations are typically somewhat
restricted in the availability of capital equipment; this in turn reduces
harvesting options. In this case, then, erosion control opportunities arise
largely from proper design and execution of activities. On the other hand,
large scale operations, measured in such terms as volume, acreage, or expense,
characteristically have greater access to capital goods and planning
expertise. This broadens the range of erosion reduction options available.
The stage of the siIvicuItural operation also influences alternatives
available for erosion control. The pre-implementation phase Includes many
options in the form of preventive measures. In contrast, operations which are
currently on-going seldom present any but mitigative options.
Land type and precipitation patterns encompass most of the environmental
conditions that influence the application of erosion controls. Local
variations may be significant and the site of the si Ivicultural operation
should be evaluated in terms of local environmental conditions.
STEP 3, ASSESSMENT OF EFFECTIVENESS AND COST
Once the various control strategies have been defined, both their costs
and effectiveness must be determined. These two measurements should be broad
enough to encompass the range of factors needed to evaluate each strategy.
Their measurement may be simple or complex depending upon the complexity of
the problem or the expertise of the user. This discussion focuses on the
various attributes to be considered when measuring or evaluating both costs
and effectiveness. Specific procedures for estimating either costs or
effectiveness depend largely upon individual situations and should rely upon
external assistance by technicians.
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Step 5A; Effectiveness
Erosion is a complex process; its intricacies and the aberrations caused
by si IvicuItural management are in the realm of hydrologists and soil
scientists and are beyond the scope of this report. However, in order to
conduct a cost-effectiveness analysis of erosion controls, it is necessary to
define the information needed about the process. In the context of this
report, effectiveness should embody a measurement of on-site soil loss as it
relates to water quality. In some cases this may be directly quantifiable. In
others, various attributes may need to be used as indicators of increased
erosion; these generally arise from cause-effect relationships, and include
the percent removal of forest canopy, degree of soil disturbance, number of
miles of road, and so forth. Effectiveness can be a relative measure such as
the percent reduction of the probable erosion without controls to the
predicted erosion with controls, or it can be an absolute measure like
kilograms of soil loss per hectare per year.
System effectiveness—
At this point in the discussion it becomes useful to develop the concept
of "system" effectiveness. The effectiveness of most erosion controls,
notably mitigative ones, is measured at the source. For example, installing
water bars may be 80-percent effective in reducing erosion from skid trails in
certain conditions. However, the impact of si Ivicultural management, a set of
activities which interacts with the environment in many ways, is usually
considered on an area basis—hence the concept of non-point source pollution.
The point is, the measurement of a control's effectiveness should be
representative of its contribution to the reduction of management impact
rather than to a single source.
To illustrate, suppose a forest manager has conducted an appraisal of the
impacts that are likely to occur from a si Ivicultural operation. He has
determined that skidding logs to landings will contribute to approximately 20
percent the impact of the entire operation, the installation of the road
system will account for about 50 percent of the entire impact, and other
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activities will account for the remaining 30 percent of the impact.
Previous research has shown that In these conditions water bars will
reduce skid trail erosion by about 80 percent; and that proper Installation of
culverts, ditches, and energy dlssipators In the course of road construction
should reduce Its Impact by 50 percent. (This type of analysis should extend
to all major activities and their Impacts.)
On the basis of partial effectiveness alone, water bars would appear to
be more effective In reducing erosion than would modifications in road design.
However, In terms of system effectiveness, or by taking all activities, their
respective Impacts and the effectiveness of reducing these Impacts by applying
controls, road design modifications become more effective than water bars.
This can be shown by using the simple relationship:
(L,) x (CA> = EI
where
L] = partial effectiveness of control number 1 for reducing
the erosion Impact of activity A;
C/\ = contribution of activity A to total project Impact;
Ej = system effectiveness of control number 1.
In this example, the calculations are:
80% X 20$ = 16$ system effectiveness for water bars
(or potential erosion reduced by 16$);
50$ X 50$ = 25$ system effectiveness for road design
modifIcatIons(or potential erosion reduced by
25$).
Time and system effectiveness—
Time may also be Important when evaluating effectiveness. To Include
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time in the analysis, a slight redefinition of system effectiveness is needed.
This requires estimating the total project Impact over the planning period
(e.g., over a number of years) and also determining the portion of the total
impact that occurs in each time segment (e.g., annually).
To Illustrate, refer again to the example above Involving water bars on
skid trails. Partial effectiveness Is 80 percent although the contribution of
the skidding activity Is 20 percent of the total Impact of silviculture. Now,
suppose this evaluation applies on ly to the first year of an operation that
will continue over a period of 4 years. Further suppose, of the total project
impact that occurs during the 4 years, only 10 percent of It occurs in the
first year. By redefining system effectiveness of an erosion control In terms
of the reduction In total Impact that occurs over a number of years, the
normalization formula becomes:
x (lt) = E1ft
where
L1 ,t = partial effectiveness of control number 1 in year t;
C/\,t = contribution of activity A to the project Impact that
occurs in year t;
If .= portion of the total project impact that occurs In year t;
El,t = Vear "*" effectiveness of control 1 for reducing total
Impact.
For year 1 in the example, the calculations are —
(80$) x (20%) x (10$) = 1.6$.
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Given the conditions in the example, placing water bars on skid trails in the
first year of operation will reduce the total 4-year impact on erosion by 1.6
percent, assuming weather conditions are similar over all years.
If the estimates are extended to each of the 4 years, the following
tabulation can be developed.
Year L1>t CA,t It El,t
t = 0 80 20 10 1.6
1 50 30 40 6.0
2 40 20 30 2.4
3 30 20 20 1.2
£ = 11.2$
Total system effectiveness of an erosion control over time, then, is
equal to the sum of the annual effectiveness measures. In this example, total
system effectiveness of water bars on skid trails is 11.2 percent; this
control would reduce erosion impact occurring over 4 years by 11.2 percent.
If time preference Is important to the monetary aspects of erosion
control decisions, discounting can be applied to the annual values (see the
section "Cost" in this chapter for a discussion of discounting).
This example presents a simple approach to determining the effectiveness
of erosion reduction techniques; its purpose, though, illustrates the concept
of system effectiveness which must be incorporated into the analysis in order
to make these measurements commensurable with project costs. Only when the
data are normalized in this fashion Is It correct to speak of
cost-effectiveness criteria for evaluations.
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Many other factors could be taken into account when considering various
aspects of effectiveness measurements. Some will be subjective and depend
upon judgment or experience while others can be fully quantified. The major
consideration is that the measurement of effectiveness must contain the
information that is relevant to the criteria upon which the decision will
eventually be made.
Step 3B; Cost
As a definition, cost is the measure of what must be given up in order to
achieve something. Cost estimates need not be accurate to the last dollar,
but an informed decision requires that cost information be accurate enough to
be comparable to the measures of effectiveness. Frequently the actual and
exact costs and effectiveness figures will not be known. A probable range,
however, can frequently be agreed upon. Thus the cost and effectiveness
components can be expressed in most probable ranges such as costs: $35-$50,
the probability of cost being within this range is 90 percent (e.g., 10
percent of the time the costs will be higher or lower).
Application and performance of erosion controls are closely linked to
on-site characteristics. Similarly, the relevant costs used in evaluating
controls are those directly linked to the si IvicuIturaI activies on the site.
Indirect costs stemming from erosion control which occur "off-site" (for
example, loss of regional income or unemployment) are beyond the scope of this
cost-effectiveness analysis method.
Costs can generally be classified into two distinct groups—outlays or
opportunity costs.
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Step 3B1 : Outlays-
Outlays are the total money expenditures necessary to achieve a specified
level of erosion control. Outlays can be classified in various ways.
Identifying (a) the total incremental costs due to erosion control, (b) the
portion of this increment that is composed of separab I e or traceable costs,
and (c) the Joint costs of the increment is the most useful procedure.
Incremental costs are the relevant costs for evaluating erosion controls
that are related to non-point source pollution. As an example of determining
incremental costs (following a discussion by Kemper and Davis 1976), assume a
gross classification of management costs including harvesting, access, and
cultural treatment costs. The computation for the net cost of erosion control
becomes :
C = (Hj - Hs) + (Aj - As) + (Tj - Ts)
where,
C = the net or incremental cost of erosion control;
H- = harvesting costs including erosion controls;
H = costs of commonly used harvesting practices;
A- = costs of including erosion controls to access;
A = costs of providing "standard" access;
T- = costs of cultural treatments including erosion controls;
T = costs of commonly used cultural treatments.
Actual applications of this technique will likely require greater
disaggregation among costs.
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Separable and joint costs for erosion control should be identified only
for the i ncremental costs that arise in si Ivicultural management as a result
of increased pollution abatement efforts. This focuses the analysis on the
two major objectives—erosion control and silviculture. These costs are
identified to facilitate cost accounting procedures. In this way costs can be
allocated to their sources, such as labor, materials or equipment.
Separable costs can be directly traced to outputs—in this discussion, the
output Is erosion control. To illustrate, suppose an area that has been
harvested is seeded with grass so that a protective cover is quickly
established. The purpose of this activity is solely to reduce erosion and
protect water quality until the forest crop becomes established. The cost
(incremental to "usual" si IvicuItural management) of seeding the area,
composed of the labor, equipment, and materials used, can be separated from
the other siIvicultural expenses. This total value is the cost of erosion
control.
Joint costs are somewhat different. These costs are not directly
traceable to any specific outputs—expenses are incurred that produce more
than one output. Thus, the use of labor to produce erosion control may also
produce another beneficial output, and the link between the costs and the
individual outputs may not be directly traceable.
For example, suppose an access road is modified as a result of pollution
abatement activities. Some construction expenses arise because the road
itself must be protected from erosion. Other expenses are due to water
pollution abatement. Although it may be possible to identify the separable
costs for erosion control in general, it may be difficult if not impossible to
separate the expenses directly related to erosion control for the purpose of
water quality protection from the costs of protecting the road prism. This is
a case of joint costs.
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The difficulty with joint costs stems from the problem of Identifying a
realistic total cost figure. If the entire joint costs for erosion control
were charged to pollution abatement in the example above, the total costs for
pollution abatement would be overstated. Conversely, if joint costs were not
included, the total cost would be understated. Since the true total cost of
erosion control for water pollution abatement includes some portion of the
joint costs, and yet the proportion is not directly separable, an additional
method is needed to allocate the joint costs between the two outputs.
Several methods have been suggested. These include (a) relative sales
value of production, (b) physical measurements of output, and (c) average unit
cost method (Backer and Jacobson 1964). Since there are no direct revenues
generated by erosion control, method (a) will not apply here. Method (c) does
not involve directly tracing costs to specific outputs but rather calculates a
unit cost for the production In general (in the example. It would simply be a
unit cost for erosion control). It is suggested here that method (b) be used
to allocate joint costs for erosion control.
Application of the cost allocation method based on measurements of
outputs requires that the output units be specifically identified. As
previously shown, the effectiveness of reducing accelerated erosion can be
sed to compare alternative controls. A similar measure could be developed
for road prism protection as well. The joint costs could then be allocated on
the basis of the ratio of the two effectiveness measures.
To illustrate, suppose that for the joint costs Incurred in the example,
erosion controls for the road protection are estimated to be 80-percent
effective while the estimated effectiveness for water pollution abatement Is
40 percent. The ratio of the two effectiveness measure is 2:1, which suggests
that two-thirds of the joint costs should be borne as a cost of road
protection while one-third of the joint costs is due to pollution abatement.
By employing this method the portion of joint costs can be Identified and
added to separable costs to obtain a total cost figure that can be used In
cost-effectiveness analysis.
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Step 3B2: Opportunity Costs--
Opportunity costs present the second aspect of costs. In economics it is
considered appropriate to define costs in terms of the value of alternatives
foregone when achieving something (Bannock, Baxter, and Rees 1972). If the
prices for the alternatives reflect their value, these costs are identical to
outlays and should be treated as such. If the value for the alternatives are
not reflected by their prices, as in the case of "public goods" (for example,
water quality values affected by timber harvest), the opportunity cost
measures the real sacrifice involved in the decision.
Step 3C: Time as a Major Component of Cost and Effectiveness—
Measurements for costs to this point have dealt with the static case;
that is, time has not been thoroughly discussed. In order to evaluate
long-term strategies for controlling erosion, the analytical framework must
account for the effectiveness and costs that will exist In each time segment
over the planning period. To accomplish this, two conditions must be met:
first, the analyst must be able to estimate both effectiveness and costs for
each time period as far into the future as the plan dictates. Second, a
method must be available for weighing the importance of future costs or
effectiveness relative to their occurrence in the immediate future.
Stream of costs and effectiveness—
To satisfy the first condition, estimates of cost and effectiveness can
be made for each time period in the same fashion as outlined above. For each
discrete time period (month, year, etc.) costs incurred and effectiveness
gained can be estimated. These can, in turn, be arrayed to illustrate the
stream of costs and effectiveness which will be encountered over time. For
example, the cost estimates for two erosion controls over time might look like
that shown in the tabulation below. Once the data are arranged in this
manner, the second condition can be pursued.
41
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Year
1234
Control X $100 $10 $5 $0
Control Y 0 100 10 5
Discounting (the calculation of present value)—
The procedure for dealing with costs that occur In the future and the
weighing of these against the present is well established in economic
analysis. In fact, it is an economic axiom that costs incurred in the present
are weighed more heavily than the same costs that might occur at some future
date. Further, there is an inverse relationship between the weight placed on
costs and the length of time between the present and the future date in
question. This relationship is the basis of discounting or the calculation of
present value.
For example, if the choice is to pay equal costs now or next year, the
money could be placed in a bank to earn interest until next year and then be
used to pay for the cost of control. Thus the rate of bank deposit interest
would be a measure of the real value foregone (an "opportunity" cost) if the
control costs were paid in the present rather than next year. Extensive
literature exists concerning the debate on the choice of an appropriate
discount rate (see Haveman and Margolis 1977). It will simply be noted here
that the analyst should choose a discount rate that adequately reflects the
relevant opportunity costs in his temporal analysis.
To illustrate an application of discounting, refer to the tabluation for
the stream of costs for control X, shown above. In the current year costs
amount to $100, $10 for the next year, $5 for the third year, and no costs
encountered in the last year.
By utilizing the discount formula,
42
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Present value of costs
f 100 , 10 , 5 0
(1+0. 5)1 (1 + .05)2 (H.05)3
= 95.24 + 9.07 + 4.32 + 0.00
the present value of these costs amount to $108.63 at a discount rate of 5
percent. To compare the costs of controls when costs are distributed over
time, the present value of costs are the only indices that should be used.
These can be compared with discounted values for effectiveness when obtained
as previously outlined.
Step 3D Choice of analysis technique—
The measurement of costs and effectiveness is conducted in the evaluation
of each alternative. Once completed the analyst must make the choice between
one of two approaches to cost-effectiveness analysis: fixed-cost or
fixed-effectiveness. The choice must be made because cost-effectiveness
analysis is used to evaluate the contribution of a program to a specified
goal—either a budget constraint or a requisite level of effectiveness. The
choice is non-trivial because both effectiveness and costs represent many
variables as noted above.
The fixed-cost method usually relates to the objective of operating
within a budget constraint. Effectiveness indices may include many factors,
each evaluated with respect to the constrained level of cost. The alternative
which produces the greatest degree of effectiveness given the fixed cost is
usually preferred.
43
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The fixed-effectiveness procedure is essentially the converse. A
specified level of effectiveness is sought and alternatives are evaluated to
determine the least-cost given this restriction. This wiI I be the method most
often employed in evaluation of erosion controls. Given the desired level of
erosion reduction in any one time frame, the least-cost control is sought. It
is still important, however, to remain sensitive to the choice between the two
methods.
STEP 4. ANALYSIS
Analysis of the candidate programs for erosion control can proceed in
various ways. The procedure employed often depends upon the specificity of
the information available to make decisions and upon the relative magnitude of
differences between the candidate strategies. There are basically two methods
which are used to organize and analyze cost and effectiveness information.
These are (a) the model approach which relies to a large extent upon
mathematical relationships and (b) the tabular display method which is
somewhat more subjective but also more versatile (Kazanowski 1968). Either of
these methods, or some modification, can be employed in the analysis of
erosion control programs. Each has its merits and the choice between either
the model approach or the tablular display method largely depends upon the
situation. Major commitments of resources, easily quantifiable evaluation
criteria, small differences between alternatives and the availability of
analytical expertise characterize situations where the development of a model
would likely be warranted. In other cases where more subjective criteria
become important it may be that the tabular format will more adequately serve
as the analysis tool.
Model Approach
The model approach is generally used when the differences between choices
are small, parameters of costs and effectiveness are easily quantifiable and
other factors affecting choices are relatively unimportant or essentially
identical among the alternatives. To develop a model, estimates of costs and
effectiveness are made for each alternative. These estimates should include
44
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disaggregated costs for elements (labor, equipment, materials, etc.) as well
as annual estimates for both costs and effectiveness. This information can be
used later Fn project planning when the chosen control will be implemented.
Both effectiveness and cost measures are then reduced to total value indices
(present value If discounted) and these values represented in a coordinate
system. The candidate programs can then be readily plotted using the
estimated value of each index as shown for strategies A through D (see Figure
11).
i i.
AB
ADDED
DOLLAR
COSTS
SYSTEM EFFECTIVENESS
Figure 11. A simple cost-effectiveness model.
This simple example of the approach shown for illustrative purposes only,
could easily be modified to incorporate more complex analysis. For example,
various aspects of either costs or effectivenes (or both) could be represented
by functional relationships or equations and incorporated into a
multidimensional model rather than the graphical two-dimensional model shown
above. Further, uncertainty over estimates could be introduced through the
use of statistical measures of probability or dispersion. It may also be
helpful to incorporate costs disaggregated by activity or their effects of
change over time. In sum the model approach provides a broad range of
analytical opportunities if the conditions for its application are met.
The greatest advantage to using the model approach is that many choices
can be analyzed at once and with rapidity. However, there are also serious
drawbacks in the method. First, models tend to be rigid, in that assumptions
concerning various relationships are initially made, either implicitly or
explicity. If an alternative subsequently requires analysis that conflicts
with these assumptions, the model itself may require modification, often at
the cost of the time and money. Second* a serious disadvantage is the
45
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necessity for simplifying assumptions. Both effectiveness and costs must be
quantified and often expressed in a functional manner. Third, it is Iikewise
necessary that the measures be commensurable. Aspects of the evaluation
criteria that are not easily measured must either be discarded or further
assumptions must be made about their imputed values. Considerable testing of
the model may be required to validate the relationships among variables and
their sensitivity to changes.
Tabular Display
An alternate approach for analyzing choices involves the use of a tabular
display. By using this method, factors that affect decisions are not
restricted to being quantifiable or commensurable. Figure 12 illustrates two
tabular arrays. The array shown in (a) displays the basic components of the
table. Decision variables are listed across the top of the table while
alternative strategies to be considered are listed vertically. Information
can be entered into the table either in a numerical or narrative format.
STRATEGIES
1
2
3
COSTS
EFFECTIVENESS
(a) The basic tabular form
en
HI
C3
STRATE
1
2
3
COST COMPONENTS
DOLLAR COSTS
CAPITAL
NVEST.
OPERATING
COSTS
EQUIPT
LABOR
If
0^
£§
mm
SPECIAL
SKILLS
>-
>-
PPORTUN
COSTS
O
CHANNE
(b) A more detailed table (after Kazannwuki, IHfiM)
Figure 12. An illustrative example of the tabular display.
46
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The table shown In (b) is an embellishment of the basic array. Here,
costs are decomposed into dollar (outlay) costs for various activities or
components, opportunity costs, and into special requirements or other
considerations. Likewise, effectiveness measures could be disaggregated to
show the aspect of erosive action that is modified. Obviously, the possible
modifications to the format are numerous and can be responsive to specific
situations.
The tabular display relies more on judgment by the analyst than does the
model approach with its strict mathematical relationships. There is, of
course, the possibility for subjective bias, but if a consensus among several
decision-makers is used, this outcome should be minimized. In comparison, the
tabular display method mitigates many of the criticisms given the model
approach. Although it is less objective, the tabular display also allows
greater versatiIity for dealing with unquantifiable criteria like aesthetics
which often enter the decision.
STEP 5. MAKING A CHOICE
With the completion of the preceding steps, the choice of the preferred
strategy for controlling erosion must still be made. In order to do this, a^
firmly established criterion (or criteria) for choice must be used. The vital
role this criterion plays in cost-effectiveness analysis is best illustrated
by expanding upon an earlier example.
Consider the fixed-effectiveness model shown in Figure 13. Four
alternatives for erosion control (A-D) have been identified, evaluated, and
subsequently plotted on the graph. A fifth alternative, a combination of A
and B, is also considered. The minimum level of effectiveness that is
acceptable has also been identified and is shown by the broken line. The
objective is to determine which of the alternatives is most cost-effective.
47
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ADDED
DOLLAR
COSTS
MINIMUM LEVEL OF
ACCEPTABLE EFFECTIVENESS
SYSTEM EFFECTIVENESS
Figure 13. An illustration of a choice criterion.
Deductive reasoning provides some inlfial assistance. First of all, any
alternative which does not provide the mfrfimum effectiveness, or which lies to
the left of the broken line, can be eliminated from consideration. Similarly,
option AB is inferior to C and need not be considered further because although
both C and AB provide the same level of effectiveness, AB costs more. The
choice reduces to a selection between C and D with neither being clearly
superior. This is where a specific criterion for choice is needed.
A criterion is a rule or standard which can be used to rank alternatives
and to choose the most promising. In other words, it is a way to weigh costs
against effectiveness. When using a model like the one shown in this example,
the most prevalent criterion employed is the cost-effectiveness ratio, which
is, in fact, a measure of marginal cost.
Returning to the example, the ratio can be illustrated by constructing
rays from the origin to the points on the graph representing the alternatives.
Angles 1 and 2 represent the cost-effectiveness ratios. The smaller the angle
the greater the "cost-effeetiveness" of the alternative. In this case the
choice would be control program C. This choice of course implies that there
is no budgetary constraint and that the objective is to minimize the ratio of
costs to effectiveness. If, however, there had been a limit on the amount of
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additional costs that could be incurred so that it precluded the choice of D
or AB on the basis of excess cost, the choice of C would have been obvious. As
suggested above, this method is equivalent to choosing the alternative which
minimizes the marginal cost of erosion control.
As one last point suppose that the cost-effectiveness difference between
two alternatives is not very large, and/or given the probability approach,
they may be reversed in a ration ranking. It will be desireable then to pick
the alternative that has the greatest potential for greater effectiveness at
the lower cost. Refer again to Figure 13. Although C is preferable to D for
the given minimum acceptable effectiveness it cannot achieve as great
effectiveness as D. If a decision was made to increase effectiveness at a
later time, a cost solution greater than D would probably occur; i.e., the AB
solution. Alternative D therefore presents an option for greater efficiency,
and would be viable if the probabilities of cost between C and D overlapped.
A choice criterion applied in the case of the tabular display method is
somewhat different than that used for the model approach. Since not all the
information in a tabular display can be quantified, a cost-effectiveness ratio
cannot be calculated. In this case, criteria concerning how information
should be structured can be employed that will lead to a solution.
Returning to the sample table shown in Figure 12(b), the various factors
underlying evaluations are listed across the top of the array. To form a
basis for making a choice, it is suggested that these factors be arranged in
decreasing order of importance from left to right. The alternative erosion
control strategies should also be listed in order, vertically, beginning with
the strategy which meets the most important (first) criteria to the greatest
extent, and so forth. By arranging the table in this manner a number of
alternatives can be evaluated and the best two or three identified. The
ultimate selection is then generally based on a judicial evaluation with
reference to the requirements of the situation and the objective of erosion
control (Kazanowski 1968).
49
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By relying upon clearly stated objectives and requirements developed In
lier steps, the possibility for subjective bias should be minimal. That
is given the goals of the analysis and the criteria to evaluate alternatives,
there should be little disagreement about the solution.
ear
By following the steps outlined above and by using good quality
information, the recommended choice for controlling erosion will be
economically expedient. Even so, it is advisable to undertake two final
tasks. It is always a good idea to re-examine the recommended program to
assure its technical feasibility. This Is highly important because of the
wide variety of environmental conditions encountered in si Ivicultural
operations. Second, the entire process (Steps 1-5) should be documented.
This provides the decision-maker with a record of the assumptions,
limitations, and conclusions the analyst encountered while producing his
recommendation. These two final tasks round out the entire procedure for
cost-effectiveness analysis.
CONCLUSION
Cost-effectiveness analysis, as discussed in this chapter, has
demonstrated its usefulness for helping choose between alternatives that
control erosion. It is certainly not the only economic model that Is
applicable to this kind of evaluation; even so. It includes basic economic
principles, and although it can be readily adapted to many circumstances by
modifications, the basic structure will not change.
Some of the limitations of the cost-effectiveness technique should be
identified. (1) ln some cases, reliance upon the ratio between costs and
effectiveness as the sole criterion for choice Is unwarranted. This stems
from the fact that in the use of ratios, the actual magnitude of the numerator
and denominator tends to be Ignored. Even so, If magnitudes are arbitrarily
r ited a selected alternative may be biased because of the limitation.
es where ratios present the greatest problems are those that Involve risk.
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The magnitude of what Is being risked has a bearing on •'he acceptability of
the risk. The use of ratios ignores the effect of the magnitude of the risk,
and hence its acceptability.
(2) Examples that have been used throughout this chapter to illustrate
that certain aspects of cost-effectiveness analysis have been site-specific in
their application. This is not intended to imply that cost-effectiveness
analysis can only be applied to a geographic area of high resolution.
Site-specific examples have been used to illustrate +he close link between
man's activities and the response by the environment, larger scale
applications are well within the realm of cost-effectiveness analysis. In
fact, when very large geographic areas are considered, col-effectiveness
analysis may be one of a very few models that could be used.
As the geographic scale becomes larger, data regarding the environment
and its response to manipulation tend to become more imprecise. Data are
aggregated and specific responses are lost to average measures. In this case,
uncertainty becomes a more important factor in both cost and effectiveness
measurements. The cost-effectiveness model can certainly accomodate this,
although the complexity of the estimating procedures is greatly increased and
the precision of the estimates reduced.
As the scale of application increases, more tools may be. needed to
facilitate analysis. Multivariate statistical techniques may become valuable
as cost or effectiveness estimating devices. Large numbers of alternatives
may lend themselves to analysis by optimization techniques like linear
programming.
(3) A final comparison between a site-specific application of cost-
effectiveness analysis and one that is conducted for a larger area can be
made. Applications involving large areas focus more upon determination of
cost-effective programs of erosion controls and their scheduling rather than
determination of the most cost-effective control among individual alternative
controls. As the shift In emphasis is made from evaluation of individual
controls on a site-specific basis to programs of controls at a regional basis.
51
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the assumption must be made that the alternatives being evaluated are
cost-effective. That is, when evaluating the cost-effectiveness of programs,
the assumption is made that the controls that comprise the program have been
previously subjected to cost-effectiveness evaluations.
In retrospect, this chapter has presented a method for conducting a
cost-effectiveness evaluation of erosion controls. The method has been geared
to the specific requirements of conducting evaluations in forested
environments. The procedure is not a compendium of all aspects of
cost-effectiveness analysis, nor is it intended to be one. It has been
presented here in an effort to provide an adequate guide for conducting a
cost-effectiveness evaluation and to suggest ways to deal with potential
problems. (The reader is referred to the various texts listed in the
bibliography for specific or technical problems that may not have been
included here.)
Finally, the application of the technique need not be overly complex to
arrive at a good decision. As Kazanowski (1968, p. 139) puts it, it is
"...preferable to use simple, understandable techniques to arrive at an
acceptable near-optimum recommendation that is implemented rather than to use
esoteric techniques to define a precise optimum recommendation that runs the
risk of being relegated to dust-gathering because the responsible
dec is ion-maker(s) can neither follow nor comprehend the rationale underlying
the techniques employed."
52
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CHAPTER 4
APPLICATIONS OF COST-EFFECTIVENESS ANALYSIS
The previous chapter developed the basic concepts of cost-effectiveness
analysis. This information was presented as a series of steps performed in
the application of the method. These steps are shown in Figure 14.
OBJECTIVE
ALTERNATIVES
AS
COSTS
EFFECTIVENESS
SESSMENT OF COSTS AND EFFECTIVENESS
ANALYSIS
CHOICE
Figure 14. Cost-effectiveness flowchart.
This chapter Illustrates how, with the assistance of some specific
procedures, the cost effectiveness method presented in the preceding chapter
can be used to choose erosion controls for si Ivicultural activities. First, a
brief review of each step in the flowchart orients the user to the
requirements of an application—what kinds of information are needed and where
S3
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they can be obtained. Second, examples are presented which give the user an
opportunity to see how the steps are executed and to note some of the
I Imitations.
54
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REVIEW OF THE STEPS
Step 1. Define the Objectives
OBJECTIVE
ALTERNATIVES
AS
COSTS
EFFECTIVENESS
SESSMENT OF COSTS AND EFFECTIVENESS
ANALYSIS
CHOICE
This step defines the objective of the analysis toward which performance
can be measured and in the pursuit of which costs are incurred. This requires
famlltarity with si IvlcuItural activities themselves and their erosion
Impacts. In addition, a definition of the framework within which decisions
will be made (applicable standards, regulations, budget levels, etc.) should
be noted.
Another important component is determination of the scale at which the
analysis will be conducted. As geographic scale increases to include a
variety of environments, the objective and attendant information will become
more general to reflect the increase in variation.
Information needs—
1. Performance of alternative controls (effectiveness) is measured
relative to the objective. Thus, the objective must be specified in a manner
that lends Itself to measurement.
2. The objective should reflect the geographic scale at which the
analysis will be undertaken.
55
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3. The objective should reflect both institutional and environmental
cons(derations.
Information sources—
1. Legislation, regulations, and policies relating to water quality from
Federal, State, and local government agencies (e.g., the Water Pollution
Control Act Amendments of 1972, state water quality standards, local erosion
control ordinances).
2. Technical assistance from government agencies, universities, research
centers, private industry, and professional societies (e.g., the U.S. Forest
Service, Soil Conservation Service, extension agents.)
56
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Step 2. EstabIish Alternatives
OBJECTIVE
ALTERNATIVES
AS
COSTS
SESSMENT OF COSTS
EFFECTIVENESS
AND EFFECTIVENESS
ANALYSIS
CHOICE
Output from this step defines the opportunites for control that are
available for attaining the objective. On a small scale, opportunities arise
by employing individual mitigative and preventive controls. At a larger
scale, opportunities involve combinations (strategies or programs) of controls
that incorporate variations in environmental conditions.
Alternatives investigated are limited only by the prowess of the analyst,
and the time and money available to him. Choices should not be limited to
"business as usual." All opportunities for reducing erosion should be
investigated.
Information needs—
1. To identify opportunities for controlling erosion, information should
be obtained about the si IvicuItura I activities and the environmental
conditions within which they will take place. This information includes
current siIvicultural practices, proposed activities, and the manner in which
the activities interact with the environment.
2. Environmental variations that represent opportunities for reducing
erosion should be identified.
57
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Information sources—
1. Forestry-related technicians including foresters, hydrologists,
engineers, extension agents.
2. Research organizations like universities, government research
institutes, professional societies.
3. Technical literature, (e.g., Water Resources Research, Journal of
Forestry, Journal of SoiI and Water Conservation, Land Economics).
4. New technology, (e.g., trade journal reports on new products, U.S.
Forest Service Experiment Station Reports.)
58
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Step 3. Assessment of Costs and Effectiveness
OBJECTIVE
ALTERNATIVES
AS
COSTS
EFFECTIVENESS
SESSMENT OF COSTS AND EFFECTIVENESS
ANALYSIS
CHOICE
This step is integral to the successful application of cost-effectiveness
analysis. Choices are made almost exclusively on the basis of the attributes
measured in this step. Therefore, they must Include the range of Information
relied upon to produce a decision.
Measuring effectiveness of a control requires technical procedures and
expertise. These technical procedures are beyond the scope of this report.
It is stressed that the measurements of effectiveness must be commensurable
with the objective so that performance can be calculated.
Methods for cost assessment were presented in the previous chapter. The
required index of cost must include the total cost of erosion control related
to non-point source pollution abatement. In terms of management cost, It Is
the Increment to total costs that can be related to erosion control, beyond
"usual" operations. These costs are composed of outlays and opportunity costs
and may occur over time as we 11.
Information needs—
1. Whenever It is possible, the Incremental erosion control costs
Incurred for the purpose of abating pollution should be distilled from other
costs that arise from siIvlcultural management.
59
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2. To obtain a total erosion control cost, both joint and separable
costs must be identified in the accounting framework. Allocation of costs to
factors of production (labor, equipment, materials, etc.) Is also useful
information and should be accounted.
3. If there are commitments over time, the stream of costs should be
reduced to present value.
4. Opportunity costs are important components of total costs and should
be included.
5. Performance should be measured as system effectiveness to assure
commensurabiIity with costs and the objective.
Information sources—
1. For information on the effectiveness of controls refer to specialists
such as foresters, hydrologists, and engineers who are familiar with the
various techniques for evaluating erosion controls in the forested
environment.
2. Cost-estimating guides can be obtained by referring to private
contracting and consulting firms, professional societies, libraries, and
government agencies (USDA Forest Service, State highway departments, county
extension agent, among others).
60
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Step 4. Analysis
OBJECTIVE
ALTERNATIVES
AS
COSTS
EFFECTIVENESS
SESSMENT OF COSTS AND EFFECTIVENESS
ANALYSIS
CHOICE
Analysis uses the information obtained in previous steps and evaluates it
with regard to the objective. The form which the analysis takes depends on
the information that is included in the decision criteria. If information is
quantifiable, the model approach is a good choice. If information is less
rigorously defined and includes subjective evaluation factors, the tabular
display becomes more applicable. Choice between the fixed-cost or
fixed-effectiveness models depends upon the framework within which the
objective was defined. Extensions of analysis to include statistical cost
estimating procedures or sensitivity analysis, for example, are at the
discretion of the user.
Information needs—
1. Information on costs and effectiveness as well as the objective must
be reviewed to determine the best approach (model or tabular).
2. Review constraints on budget or performance (or both).
3. Additional decision criteria should be reviewed.
Information sources—
Refer to previous steps.
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Step 5. Choice
OBJECTIVE
ALTERNATIVES
AS.
COSTS
EFFECTIVENESS
5ESSMENT OF COSTS AND EFFECTIVENESS
ANALYSIS
CHOICE
The final step involves choice of the most cost-effective control(s). As
described in the previous chapter, some alternatives can be intuitively
eliminated, while the choice between remaining alternatives may require a
criterion to rely upon. Following a choice. It Is advisable to review the
selected alternative for technical feasibility.
Information needs—
If a choice criterion Is used (such as a ratio or a preference
consensus), the criterion Itself and how it applies to decision-making should
be explIcitly stated.
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EXAMPLE 1. COST-EFFECTIVENESS ANALYSIS APPLIED
TO CONTROL SELECTION ON A SINGLE SITE
Construction and maintenance of access roads to si IvicuItural operations
in the lodgepole pine type of the central Rocky Mountains can involve erosion
hazards, but controls can be applied to these activities that reduce erosion
and protect or improve water quality.
Step 1. Define Objective
A si IvicuItural operation was proposed for a lodgepole pine stand. The
forest manager evaluated the site and its relationship to the surrounding
environment; he consulted with water quality planners and reviewed local
regulations. As a result, he concluded that the erosion-control objective was
to reduce the total expected erosion impact over the next 4 years by 40
percent. This will keep the project impact well within the acceptable limits
throughout the duration of the project.
In steps 2-5 of this example access activities are examined and
erosion-reduction measures which must be employed to meet the objective with
controls on Iy on access activities are determined. Step 6 expands the
analysis to determine cost-effective alternatives for al I erosion-control
practices.
Step 2. Define Alternatives
Consultation with the road construction engineer yielded a description of
the access activity and the erosion hazards involved. On this site, road
sections occurred predominately on 50-percent side slopes (Figure 15). The
running surface was 14 feet, with a 2-percent outslope. Most road
construction was to be completed in the first year, harvesting and site
treatments throughout the following 3 years, with project completion in the
fourth year.
63
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CUT SLOPE
Figure 15. Cross section of a roadbed,
64
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Step 2A. Estimate Erosion from Major Source Areas—
With respect to the access activity on this site, erosion could occur on
the fill slope, the cut slope, and the road surface. Estimates by the
engineer for the erosion from these areas over the planning period are shown
in Table 9.
TABLE 9. ESTIMATED EROSION FROM SOURCE AREAS*
A.
B.
C.
Source Area
Cut Slope
Road Surface
Fill Slope
Year
1
75
25
90
2
— Tons
60
25
80
3
per mi le —
40
25
80
4
25
25
50
Total
200
100
300
*NOTE: These figures are exemplary only and are not intended to be
representative of any area.
65
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Step 2B. Determine Appropriate Erosion-Control Practices—
As a result of their knowledge about both the site and the erosion
hazards, the engineer and forest manager were able to determine erosion-
control practices best suited to mitigating specific erosion hazards (Table
10).
TABLE 10. EROSION CONTROL ALTERNATIVES
A. Surface erosion from cut slope^
1 . Grass seed
2. Grass seed and fertilizer
3. Grass seed, fertilizer, mulch
4. Grass seed, fertilizer, jute mat
B. Surface erosion from road surface
5. Close road between uses
6. Close, seed, fertilize
7. Gravel the surface
8. Asphalt surface on base
C. Surface erosion from fi I I slope^
9. Grass seed
10. Grass seed and fertilizer
11. Grass seed, fertilizer, mulch
12. Grass seed, fertilizer, jute mat
Cut slope and fill slopes are 1:1 and 1-1/2:1, respectively (see Figure 16,
p. 76).
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Step 3. Assessment of System Effectiveness
Step 3A. Calculate Local Effectiveness of Alternative Controls—
Partial effectiveness of individual controls were estimated by the forest
manager who consulted the engineeer, computer models of erosion processes,
past records, and an evaluation of specific site conditions. Partial
effectiveness estimated were made for each year of the 4-year period and they
refer to the effectiveness of the control for reducing erosion on the local
source, i.e., the cut slope (this information is shown in Table 11, p. 68).
67
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TABLE 11. TOTAL SYSTEM EFFECTIVENESS OF CONTROLS*
Calcu I at ion:
Alternati vest
A. Cut Slope
1
2
3
4
B. Road Surface
5
6
7
8
C. Fill Slope
9
10
11
12
(Step 3A) x
Partial
Effect! venessf
10
20
30
50
15
25
80
98
20
40
75
90
(Step 3B) x
Local Source
Contr i but ion§
33
33
33
33
17
17
17
17
50
50
50
50
(Step 3C) =
Act! v i ty
Contr i butioMI
75
75
75
75
75
75
75
75
75
75
75
75
(Step 3D)
System
Effectiveness
2
5
7
12
2
3
10
12
8
15
28
34
* All figures in percent.
t Numbers refer to alternative controls shown in Table 10.
t Total effectiveness over the 4-year period.
§ Based on estimated 150 tons/mile/year for a road section divided among
the cut slope, fill slope, and road surface.
^| Proportion of total impact due to access activities.
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Step 3B. Estimate Percentage Contribution of Erosion on Single Source
Area to Total Contribution of Erosion of All Source Areas—
Erosion from any single source, (i.e., cutslope), must be computed in
relation to erosion from all source areas, e.g., cut slope + road surface +
fill slope (see Table 11, p. 53). For example, total erosion over the 4-year
period for cut slopes was 200 tons/mile (see Table 9). For all areas, it was
600 tons/mile. Therefore, the percentage contribution of erosion from the cut
slope to erosion from all source areas was 33 percent, or 600/200.
Step 3C, Estimate Contribution of Activity to Total Project Impact—
Normalizing these estimates to a measure of system effectiveness requires
an estimate of the contribution of the local source to the total impact of the
project. Table 8 in Chapter 2 suggests that in Ecoregion 3100 roads involve
the greatest hazard, although the absolute share due to this activity Is not
indicated. This can only be evaluated by an investigation of site conditions
for the area where the si Ivicultural activity is proposed.
By evaluating the site conditions and comparing them with other
sllvlcultural operations in similar conditions, the impact due to access
activities over the planning period were estimated to be:
Year TotaI
1
30*
2
20$
3
15$
4
10$
Access 30$ 20$ 15$ 10$ £=75
Thus, the impact of access activities were estimated to account for 75 percent
(e.g., 30 + 20 + 15 + 10) of the total erosion impact over 4 years. No
discounting was applied to effectiveness values (see Table 11, p.68 )•
69
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Step 3D. Calculate System Effectiveness—
With information gathered from Steps 3A through 3C, calculations to
determine system effectiveness were carried out (see Table 11). For example,
Control 2 has a 5-percent system effectiveness; this was calculated 20% x 33$
x 15%.
Step 4A. Assessment of Costs
A standard accounting framework was used to develop each of the total
cost estimates. In this case the framework is shown with entries for one of
the controls (Table 12).
TABLE 12. A STANDARD ACCOUNTING FRAMEWORK APPLIED TO CONTROL 11
Unit Cost Units/Mi le =
of road
Direct Costs
Hydroseed and Mulch
Labor
Man hours $8.00 8
Materials
Seed (cwt) 26.00 8
Fertilizer (ton) 72.00 1-1/4
Mulch (ton) 150.00 3
Equipment and Overhead
Hydroseeder (hr) 70.00 4
Overhead (hr) 65.00 4
TOTAL DIRECT COSTS
TOTAL JOINT COSTS
TOTAL COSTS
$64.00
$64.00
208.00
90.00
450.00
748.00
280.00
260.00
540.00
1 ,352.00
422.00
1 ,774.00
70
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A total discounted cost value must also be determined (Table 13). This
requires that the costs be estimated for each time period so that discounting
can be applied. Costs were derived using a standard cost estimating yuicu tor
road construction. They represent costs attributable to erosion control for
water pollution abatement. Total cost figures appearing in Table 14, p. 73
are the discounted values from each time period. A discount rate of 7 percent
was appIied .
TABLE 13. MULT I-PERIOD COSTS ATTRIBUTABLE TO EROSION CONTROL
FOR WATER POLLUTION ABATEMENT
Control Year: 1234
A.
B.
C.
Cut Slope
1
2
3
4
Road Surface
5
6
7
8
Fill Slope
9
10
11
12
$ 172
287
747
5,853
$375
890
8,000 $200 $200 200
30,500 200 200 200
409
682
1,774
13,896
Total Cost*
$ 172
287
747
5,853
306
726
8,525
31,025
409
682
1 ,774
13,896
*Cost per mile of road discounted at 7 percent.
71
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Step 4B. Determine Best Combination of Erosion Controls
Table 10 (p. 66) shows the individual controls that apply to different
areas, but combinations of these controls could also be applied and should
themselves be considered alternatives. All possible combinations of controls
could feasibly be enumerated. In order to reduce the combinations that
required analysis, two steps were taken:
(1) It was noted that the controls applied to any single area (i.e., cut
slope) were generally combinations themselves (i.e., grass seed, fertilizer
jute mate; grass seed and fertilizer). Thus any combinations of controls
could only include one choice from the set of controls that apply to any
area—for example, only one of the four controls that apply to the cut slope
sould be included in a combination of controls.
(2) In order to reduce the number of combinations needing evaluation,
any combination of controls that was less than 40-percent effective was not
enumerated; nor any controls that were greater than 45-percent effective.
Since effectiveness and cost figures were estimated, it was assumed that
the values for combinations were additive. That is, a combination of controls
1 and 5, for example, would have a cost of $478 with an effectiveness of 4
percent. Table 14 summarizes the control alternatives, including possible
combinations their costs and effectiveness.
72
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TABLE 14. SUMMARY OF EROSION CONTROL ALTERNATIVES
Alternative—
A. Cut Slope
1
2
3
4
B. Road Surface
5
6
7
8
C. Fill Slope
9
10
11
12
D. Combinations
12 + 7
12 + 3
11+4
11+8
12+6+3
12+6+2
12+5+3
12+5+2
11 +8+2
11+8+1
11+7+3
11+7+2
11 + 7 + 1
11+6+1
Cost/Mi le
$ 172
287
747
5,853
306
726
8,525
31,025
409
682
1 ,774
13,896
22,421
14,643
7,627
32,799
15,369
14,909
14,949
14,489
33,086
32,971
11,046
10,586
10,471
8,353
System Effectiveness
2%
5
7
12
2
3
10
12
8
15
28
34
44
41
40
40
44
42
43
41
45
42
45
43
40
43
Ratio ($/$x100)
86
57
107
488
153
241
853
2,585
51
45
63
409
510
354
191
820
349
355
348
353
735
785
245
246
262
194
Numbers refer to alternatives listed in Table 10,
73
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Step 5. Analysis and Choice
Step 5A. Calculate Cost-Effectiveness Ratios—
To determine the most desirable control strategy In terms of the
objective, cost-effectiveness ratios were calculated for each control and
control combination. These are derived by dividing costs by effectiveness.
(Ratios are shown in Table 14.)
Step 5B. Determine Best Alternative For Reducing
Erosion for Specificed Level of Effectiveness
Using the lowest ratio as the criterion, the best choice for reducing
erosion by 40 percent was:
Control 11: grass seed, fertilizer, and mulch on the fill slope
plus
Control 4: grass seed, fertilizer, and jute mat on the cut slope.
This combination was 40-percent effective over 4 years and had a total
discounted cost of $7,627 per mile of road.
A sensitivity analysis is another means of showing how responsive total
costs are to various levels of erosion-control effectiveness. To facilitate
analysis, the most cost-effective control(s) was determined for cost-
effectiveness levels 5 through 55 percent at 5 percent Increments. This
analysis Included: (1) determining which controls or combinations met the
effectiveness level, for example, 5 percent (see Table 14); and (2) evaluating
these alternatives on the basis of their respective cost-effective ratios (see
Step 5A or Table 14) to determine the cost-effective choice. The results of
these analyses are shown In Table 15. Using 5 percent Increments Is purely
illustrative of a sensitivity analysis procedure. It should be noted that In
this example although access activities account for 75 percent of the project
impact, a maximum of only 58 percent of the impact could be mitigated using
the controls available, and at a cost per mile of $50,774.
74
-------
TABLE 15. TOTAL COSTS OF EROSION CONTROL FOR ACCESS ACTIVITIES
A 1 ternative
2
10
10
10+2
11
11 + 1
11+3
11+4
1 1+7+3
11+7+4
12+7+4
12+8+4
Step 3D
Approximate
Level of System
Effectiveness
5*
10
15
20
25
30
35
40
45
50
55
58 (maximum
possible)
Step 4A
Total Cost
per mi le
of need
$ 287
682
682
969
1774
1946
2521
7627
11046
16152
28274
50774
75
-------
Figure 16 Is a graph of the Information shown fn Table 15. This cost
curve shows erosion control costs for access activities on this site for
various levels of erosion impact reduction when cost-effective alternatives
are used.
I
1
I
g
s
I
$55.000 .
50.000 -
45.000 -
40.000 .
35.000 -
30.000 .
29.000 -
20.000 .
15,000 -
10.000 -
5.000 -
;
/
/
/
/
/
/
/
/
//
f ! r i i i i i i i
6 10 15 20 25 30 35 40 45 50 55
Percent level of effeeti«ene»
Figure 16. Total cost for erosion control for access activities.
78
-------
Step 6A. Expand Analysis to Determine Cost-Effective Alternatives for All
Erosion-Control Practices
At this point the analysis was expanded to include not only access
activities, but analysis of erosion control alternatives for harvest and
cultural treatments as well. To determine the best strategy for the harvest
area as a whole, it would be possible to simply include the controls for
harvest and cultural treatment activities as further alternatives that could
be combined with access controls. The analysis could then proceed as outlined
above for access activities only.
In this case, the analysis was done a little differently. The most
cost-effective controls for various levels of effectiveness were determined,
but for access, harvest, and cultural treatment activities separately. These
results appear in Table 16 (note that costs are now comparable on a per acre
basis).
77
-------
TABLE 16. COST-EFFECTIVE ALTERNATIVES FOR ALL FORMS OF EROSION CONTROL
Step 6A
A. Access
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
B. Harvest**
1.
2.
C. Cultural
1.
Step 6A
Level of
Effec-
tiveness
*
5
10
15
20
25
30
35
40
45
50
55
58
5
10
Treatments**
5
Step 6A*
Total
Cost
$ 1.32
3.20
3.20
4.54
8.32
9.12
11.82
29.79
51.78
75.71
132.53
238.00
43.00
56.00
2.00
Step 6B
Marginal
Cost
$ 1.32
1 .88
1.34
3.78
.80
2.70
17.97
21.99
23.93
56.82
105.47
43.00
13.00
2.00
Step 6B
Rank
1
2
3
4
6
7
8
9
10
11
14
15
12
13
5
*Cost per acre of harvested area; it was assumed that these were 3 miles
of road per section (640 acres) of harvested area.
**Harvest activities were estimated to account for 15 percent of the
total four-year Impact; cultural treatments for 10 percent.
78
-------
Just as a total cost curve relating costs to various levels of
effectiveness was developed for access controls only (see Figure 16), three
curves were developed showing total costs for each of three activities. This
is shown in Figure 17, and was developed using the information from Table 16.
Figure 17. Total Cost Curves for AI I Activities.
$200 .
$100 -
J50 -
Harvest
Cultural treatments
5 10 15 20 25 30 35 40 45 50 55 60
Percent level of effectiveness
Using this kind of information, a sensitivity analysis can be undertaken
to determine a cost-effective strategy for erosion control In general,
including control possibilities for all three kinds of activities.
Step 6B. Calculate Marginal Costs for All Erosion-Control Alternatives
In Order to Rank Alternatives
The marginal cost, or the additional cost at an increment of 5-percent
effectiveness, were calculated for each alternative. The alternatives from
all activities were then ranked In order of increasing marginal cost (with the
rule that alternatives from any activity must be sequential—i.e., alternative
5 for access must come before alternative 6). The last column in Table 16
shows this ranking.
79
-------
Step 6C. Estimate Total Costs in Relationship to Levels of Effectiveness
Using the ranking (Table 16), a final table can be constructed to show
the strategy as it relates to various levels of effectiveness. Table 17 shows
the levels of strategy effectiveness (cumulative effectiveness), the costs of
the strategy (cumulative cost), and the alternatives that comprise the
strategy for a level of effectiveness.
TABLE 17. TOTAL COST RELATIONSHIP TO EFFECTIVENESS LEVELS
Step 6C Step 6C
Rank Alternatives
1 (A-1)
2 (A-2)
3 (A-3)
4 (A-4)
5 (C-1)
6 /A R ^ -i. f f"*» 1 ^
\ r\ *s j • \ \s i /
1 (A-6)+(C-1)
Q (r\~//'(O**I/
9 (A-8)+(C-1)
10 (A-9)+(C-1)
11 (A-10)+(C-1)
12 (A-10)+(C-1 )+(H-1 )
13 (A-10)+(C-1 )+(H-2)
14 (A-11 )+(C-1 )+(H-2)
15 (A-12) + (C-1)-KH-2)
Step 6C
Cumulative*
Cost
$ 1.32
3.20
3.20
4.54
6.54
10.52
11.12
13.82
31.79
53.78
77.71
120.71
133.71
190.53
296.00
Step 6C
Cumulative
Effectiveness
Percent
5
10
15
20
25
30
35
40
45
50
55
60
65
70
73
Cumulative total of marginal costs.
80
-------
The information In the table can be transferred to a graph to Illustrate
the total cost relationship in effectiveness levels. This is shown In Figure
18.
I
I
o
§ 150
T r \ 1 1 i 1 1 1 1 r 1 i 1 r
5 10 15 20 25 30 35 40 45 50 55 60 6$ 70 75
Percanl Itval of •ff«ctiv*r»s*
Figure 18. Total cost for erosion control.
As shown by the curve, a maximum of 73 percent of the erosion impact of
the project could be reduced by applying the most effective controls, although
this would cost about $296 per acre. The graph clearly Illustrates how costs
Increase with higher levels of control. Notably, costs begin to escalate
dramatically above a 40 percent reduction.
81
-------
SUMMARY
This example has shown, first, how Individual controls can be evaluated.
Second, it demonstrates how controls can be combined Into further alternatives
and how a cost-effective choice can be made from all of these in relation to
one siIvicuItural activity. It has also displayed an application of
sensitivity analysis relating total erosion-control costs to various levels of
control. Finally, the example has illustrated how a cost-effective choice can
be made for controls relating to all activities in a siIvicultural operation.
82
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EXAMPLE 2: CHOICE OF PREVENTIVE EROSION CONTROL
FOR MECHANICAL SITE PREPARATION IN THE SOUTH
This example applies cost-effectiveness analysis to a situation in which
not all cost or effectiveness measurements can explicitly be made.
Opportunity costs not directly measurable in dollar terms are included in the
analysis, and to accomodate these a tabular display is used. Further
difficulty In determining the portion of total costs due to erosion controls
necessitated the use of only management costs—a problem that can often be
encountered.
Objective
Some sort of mechanical site preparation is usually required to establish
a well-stocked plantation with superior trees. Erosion rates can be high
during some mechanical site preparation procedures, and the main control will
be that of maintaining or creating vegetative ground in the treated area, plus
leaving a streamside management zone. The type of mechanical site preparation
is governed by both the tree species to be planted and the size and amount of
residual stand after clearcutting. In this example, loblolly pine is being
planted in the upper coastal plain in an area having a residual hardwood stand
of about 6 inches in diameter. The landowner wants to establish a
we 11-stocked plantation with minimum investment and he needs to cut the
present erosion rate in half—to approximately 6 tons per acre per year. The
6-ton erosion rate coupled with a streamside management zone that is
90-percent effective will reduce erosion to acceptable levels.
Alternatives
The landowner has several alternatives to choose from, but some of them
have environmental tradeoffs. He can choose from two commonly used site
preparation treatments: (1) To fell the residual hardwoods with a KG shearing
blade, rake the debris into a windrow and burn it (which would affect air
quality), and machine plant at a cost of $90 an acre. With this procedure the
erosion rate is expected to be about 13 tons per acre per year; or (2) To
83
-------
shear, rake and windrow, disk, and machine plant at a cost of $112 per acre,
with erosion reduced to 10 tons per acre per year.
Neither of these alternatives meets the 6-ton criteria however; as a
consequence the usual site preparation treatment must be modified. This will
lead, in turn, to other alternatives:
(3) To shear, rootrake and windrow, machine plant, and seed with grass at
a cost of $110 per acre and an expected erosion rate of 4 tons per acre per
year. However, costs will remain relatively high and there will be some
reduction in tre» seedlings survival and reduced timber yields per acre.
(4) To shear and hand plant provided planting crews are available; and
during the second year, release spray with herbicides for a total cost of $66
per acre (present value). The erosion rate is expected to be approximately 3
tons per acre per year. However, there is a tradeoff between erosion control
and introduction of herbicides into the forest environment which could, in
turn, have a water quality impact.
(5) To shear, chop, burn, and hand plant would cost $81 per acre with
erosion expected to be 3 tons per acre per year. Prescribed burning, as wfth
release spraying, minimizes the vegetation that competes with seedlings.
However, burning would impact air quality and some ash could enter the stream.
(6) A final alternative would be to use the seed-tree harvesting
system—scarify the soil, use hand injection of herbicides to kill the
residual hardwood and thin the natural regeneration at the age of 4 to 5
years. Trade-offs include (a) the dead hardwoods left standing would
adversely affect aesthetics and (b) the resulting stand of pine would not be
of superior tree stock, resulting in a 20- to 25-percent reduction in
production. The erosion rate would be about 3 tons per acre, and the
treatment would cost (at present value) $65 per acre.
84
-------
All of the above alternatives are technically possible provided that hand
planting crews, spray equipment, and mechanical site preparation equipment are
available. But in many areas hand planting cannot be used because of the
scarcity of labor crews.
Analysis in this case utilizes the tabular display (Figure 19).
Alternatives are presented in descending order of preference, depending upon
subjective weights placed upon the various aspects of effectiveness and costs,
based on the judgement of several individuals. In this case, the preference
rankings are not entirely related to dollar costs. An important consideration
is in the trade-offs indent!fied for each alternative. The preferred
alternative is shown as number (1).
As a matter of contrast to the alternatives presented, on hardwood stands
less than 4 Inches in diameter, a simple drum chop and hand planting could
have been used, followed by release spray at a cost of $54 per acre and an
erosion rate of 1 ton per acre per year. This demonstrates that the size of
the residual stand has a marked impact on site preparation treatment, the
resulting erosion rate, and the cost of tree planting. With the use of
prescribed burning during the rotation, future plantations could be
re-established using this type of treatment or something similar in intensity,
because the hardwoods will be kept small enough that a light treatment can be
used. Intensely prepared sites are the result of two factors: Forest stands
now contain large hardwoods and many more forest stands are being brought
under management.
85
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STRATEGIES
(1) Shear, hand plant and
release spray Kith herbicide
in the second year
(2) Shear, chop and burn, and
hand plant
(3) :"eod tree harvest, scarify
soil, hand injection of
hardwoods, fhln at 4-5 years
W Shear, root-rake, windrow,
seed with grass, machine
plant
(5) Fell hardwoods with a KG
blade, rake into windrows,
burn, machine plant
(6) S.'mar, rake, windrow, disk,
machine plant
COSTS
Cost per acre'
$ 06
81
65
110
90
112
L
Special Requirements
a) Planting crews
t>) Spray equipment
Special equipment
needud
Special equipment
needed
Trade-offs
Herbicide use
Burnfnq may affect
air
a)Uns!qhtly dead
Ire-PS
b)No superior troe
c)^f-nucf*d yields by
70-25 percent
a^FUfduced seedling
surv i va 1
b)Reduced timber
yield
a)Ai r qua 1 i ty
affected
b)Si ze of residual
trees 1 imit Ing
EFFECTIVENESS
tons/acrefyear
3
3
3
4
13
10
'present value discounted at 7%
Figure 19. Tabular Display.
86
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EXAMPLE 3. LARGE AREA ANALYSIS
This example uses cost-effectiveness analysis to evaluate erosion-control
strategies that apply to extensive areas. This is in contrast to the previous
two examples which determined a cost-effective strategy for reducing erot;cn
in an area generally homogenous with respect to erosion response to manageme-.t
activities. As scope of analysis broadens in a geographic sense,
environmental variety increases and erosion responses to si Ivicultural
management may differ. For example, within a river basin of several thousand
acres, a number of forest types can occur, and si Ivicultural management in
each will likely produce different erosion responses.
Cost-effectiveness analysis applied to large areas shifts its emphasis from
choice between individual controls for specific areas to choice between
erosion control strategies that apply to entire segments of a region. Example
1 produced an erosion control strategy for given conditions in the central
Rocky Mountains. On a large area basis, this strategy would become only one
of the many alternatives relating to other sites. In general, the problem at
the large scale is one of evaluating alternative strategies, made up of
cost-effective combinations of individual controls, which can be combined to
produce a cost-effective erosion reduction program.
Step 1. Determine Objective
This analysis applies to a region in the Southeast, roughly corresponding
to a large river basin. (The data presented in this example are crude and are
not intended to be representative of any specific area.) The region
encompasses portions of two ecoregions (2200 and 2300), several forest types
and two physiographic zones. SI IvicuItural management takes place throughout
the region although the erosion Impacts differ.
87
-------
In this case, a regional agency (such as a State Water Quality Division or
a Regional Council of Governments) instructed the analyst to evaluate
erosion-control strategies that could be applied throughout the region In a
cost-effectiveness analysis framework to determine a set of programs
corresponding to various levels of erosion reduction. Specifically, the
objective included two steps: (1) determine cost-effective programs for
effectiveness levels of 25 and 45 percent on a region-wide basis, and (2)
indicate the total costs of these programs.
Step 2. Identify Alternative Strategies
Step 2A. Stratify the Region —
To identify alternative strategies, the region was stratified into areas.
This was done so that each strategy would be representative of an area in
terms of erosion control costs and effectiveness. Stratification was
accomplished on the basis of two features: (1) physiographic characteristics
and (2) forest types. With reference to local information and to Chapter 2 of
this report, the system in Table 18 was developed.
TABLE 18. REGIONAL STRATIFICATION
1. Mountains
a. Yellow Pine
b. Virginia Pine
c. Oak-Hickory
2. Piedmont
a. Loblolly-Shortleaf Pine
b. Oak-Hickory
88
-------
Step 2B. Identify Strategies for Each Area--
Strategies for each area were identified with the help of foresters and
hydrologists familiar with local conditions. The following procedure was
used:
(1) Tables in Chapter 2 were used to determine erosion potentials
associated with each forest type and for various siIvicuItural
activities in each area.
(2) Cost-effective strategies were developed in response to these
potentials. In some cases, cost-effectiveness analysis was used to
identify the best combinations of controls for an area. (See
Example 1 for details of these procedures.)
(3) Three estimates were made for each strategy corresponding to three
levels of effectiveness. These were generally a low, medium, and
high level representing approximately 20-, 40-, and 60-percent
local effectiveness. (See Example 1 for details of this procedure.)
As a result of this procedure, the alternatives shown in Table 19 were
identified. The table shows, for example, that for the oak-hickory type found
in the mountains a cost-effective strategy with primary control emphasis on
access and harvest activities can reduce erosion impact in that type by
approximately 20 percent when applied at a relatively low level. By incurring
higher costs, the same strategy could increase Its local effectiveness to 40
percent. Thus, for each forest type in the two physiographic areas there is
one erosion control strategy which can be applied at any of three levels.
Each of these levels represents an alternative although a higher level for a
strategy includes the lower levels.
89
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TABLE 19. EROSION CONTROL STRATEGIES
Area
Strategy
Level of
Effectiveness^
1 . Mounta i ns
a . YelIow Pi ne
Access-CuIturaI
treatment
b. Virginia Pine Access-Cultural
treatment
c. Oak-Hickory Access-Harvest
2. Piedmont
d. Loblolly- Cultural treatment-
Short leaf Pine Harvest
e. Oak-Hfckory Access-Harvest
1. Low
2. Medium
3. High
4. Low
5. Medium
6. High
7. Low
8. Medium
9. High
10, Low
11. Medium
12. High
13. Low
14. Medium
15. High
Entries indicate the major emphasis of controls comprising
the strategy.
"Approximate values are
Low = 20%
Medium = 40/K
High = 60%
90
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Assessment of Costs and Effectiveness;
Step 3. Estimate System Effectiveness
In order to normalize local values into measurements reflecting the system
effectiveness of various strategies on a river basin scale, an estimate was
required of the relative proportion that siIvicultural management in each of
the areas made to the total erosion impact within the basin (Table 20).
TABLE 20. SYSTEM EFFECTIVENESS OF STRATEGIES
Area Acres1 ^T Y A^er"ative
Shared X Strategy =
1 . Mounta i n
a. Yel low Pine 20,000 20% 1.
2.
3.
b. Virginia Pine 15,000 15 4.
5.
6.
c. Oak-Hickory 5,000 5 7.
8.
9.
2. Piedmont
a. Loblol ly- 35,000 35 10.
Shortleaf Pine 11.
12.
b. Oak-Hickory 25,000 25 13.
14.
15.
20$
40
60
20
40
60
20
40
60 -
20
40
60
20
40
60
System
: Effectiveness
4%
8
12
3
6
9
1
2
3
7
14
21
5
10
15
Average number of acres undergoing siIvicultural management annually.
2
Percentage share of total si IviculturaI erosion impact occurring within
the total area.
91
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Two steps were taken to accomplish this:
(A) The number of acres managed for silviculture were estimated for each
area. And an estimate for each area was made for the average annual
erosion per acre due to siIvicultural management.
(B) The products of these two values were then translated Into
percentages reflecting the relative share of the river basin erosion
occurring in each area.
These relative shares are shown in the column "Relative Share" in Table 20.
The table shows, for example, that approximately 60 percent of the
silviculture-related erosion within the basin occurs in the Piedmont Area
(e.g., 25 + 35 percent), 40 percent in the Mountain Area, and 35 percent in
the loblolIy-shortleaf pine type.
Assessment of Costs and Effectiveness:
Step 4. Estimate Total Costs for the Region
In Table 21 three cost estimates were made for every strategy corresponding
to the three levels of local effectiveness. (Please note: Only one strategy
for each type is shown In Table 21.)
92
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TABLE 21. TOTAL COSTS FOR REGION
Area Acres* Alternative
1. Mountain
a. Ye I low Pine 20,000 1.
2.
3.
b. Virginia Pine 15,000 4.
5.
6.
c. Oak-Hickory 5,000 7.
8.
9.
2. Piedmont
d. Loblol ly- 35,000 10.
Short leaf 11.
12.
e. Oak-Hickory 13.
14.
15.
Unit
Cost/Acre
$ 2.50
15.00
90.00
3.00
10.00
40.00
20.00
40.00
60.00
5.00
20.00
130.00
3.00
15.00
35.00
Step 4
Total Cost
( I n thousands)
$ 50
300
1800
45
150
600
100
150
350
175
700
4550
75
375
875
^Average number of acres annually undergoing active si IviculturaI
management.
93
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Table 22 summarizes the information pertaining to the alternative
strategies.
TABLE 22. SUMMARY OF ALTERNATIVE STRATEGIES
Step 2A
Area
1. Mountains
a . Ye 1 1 ow
Pine
b. V irginia
Pine
c. Oak-
Hickory
2. Piedmont
d. Loblol ly-
Shortleaf
e. Oak-
Hickory
Step B Step 2B Step 3 Step 4
. .- . Percent Percent ,- . . „ .
An Erosion , - . Total Cost
~ , , -, . Level of System r n
Control Strateqy r,, ,. ._,, ' . For Region
Effectiveness Effectiveness
Access-Cul tura 1 1 .
treatments 2 .
3.
Access-Cultural 4.
treatments 5.
6.
Access-Harvest 7.
8.
9.
Cultural 10.
treatments-Harvest 1 1 .
12.
Access-Harvest 13.
14.
15.
Low (20^)
Medium (40$)
High (60%)
Low (20?)
Medium (40%)
High (6C£)
Low (20?)
Medium (40$)
High (60$)
Low (20?)
Medium (40$)
High (60$)
Low (20?)
Medium (40$)
High (60$)
4?
8
12
3
6
9
1
2
3
7
14
21
5
10
15
( in thousands)
$ 50
300
1800
45
150
600
100
150
300
175
700
4550
75
375
875
94
-------
Erosion-control cost estimates were made on an annual average per acre
basis (Cost per acre x Number of acres = Total cost). That is, the estimates
were intended to reflect the average annual cost per acre of applying the
erosion-control strategy to si IvicuItural management within the area. The
costs depended largely upon controls selected to comprise the strategy and
their individual costs. Again, cost estimates were made by persons familiar
with local conditions. In addition, reference was made to cost estimates by
Federal and State agencies and private forestry companies In the region.
Because the objective of the analysis is to determine the most
cost-effective programs for the region as a whole, it was required that system
effectiveness (Step 3) be compared with total incremental costs (Step 4).
Cost estimates are based on a unit cost (i.e., si IvicuItural type). Because a
different number of acres are undergoing active siIvicultural management in
each unit in each year, to obtain a total cost for erosion control requires
that the total erosion control cost for each area and siIvicultural unit
within it be determined. Thus, the product of the unit cost (in Table 21, for
example, 2.50 per acre in the Yellow-Pine type) and the number of acres
affected (20,000 acres) will yield the total cost for each area ($50,000),
shown also in Table 23.
95
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Ana lysis and Choice
Since the objective could not be reached with the application of a single
erosion-reduction strategy in one area only, the regional program was made up
of strategies that affected various areas within the region. Thus the program
was composed of strategies affecting different areas, although the intensity
at which they were applied could differ from area to area.
Assessment of Costs and Effectiveness;
Step 5. Determine Marginal Costs and Effectiveness
for Each Level of Strategy
Marginal analysis was used to evaluate the strategies and determine how
they should be combined to produce a cost-effective program. To begin, the
marginal cost and marginal effectiveness values for each level of each
strategy were determined (Table 23).
96
-------
TABLE 23. MARGINAL ANALYSIS
Step 5
. A 1 ten-
Area ,.
nati ve
Cost
Total Marginal
Cost Cost
Step 5
Effect! veness
System Margina
Step 6
Margi na 1 *
, C/E
Ratio
( in thousands)
1 . Mounts i n
a. Ye I low Pi ne 1 .
2.
3.
b . V i rg in ia Pi ne 4.
5.
6.
c. Oak-Hickory 7.
8.
9.
2. Piedmont
d. Loblolly- 10.
Shortleaf Pine 11 .
12.
e. Oak-Hickory 13.
14.
15.
$ 50
300
1800
45
150
600
100
150
300
175
700
4550
75
375
875
$ 50
250
1500
45
105
450
100
50
150
175
525
3850
75
300
500
4
8
12
3
6
9
1
2
3
7
14
21
5
10
15
4
4
4
3
3
3
1
1
1
7
7
7
5
5
5
12.5
62.5
375.0
15.0
35.0
150.0
100.0
50.0
150.0
25.0
75.0
550.0
15.0
60.0
100.0
^(Marginal Cost) ^ (Marginal Effectiveness) = Ratio
97
-------
To illustrate, Alternatives 1 through 3 refer to the application of a
single erosion-control strategy to the yellow pine forest type in the
mountains. Alternative 1 is a low level of control, while Alternatives 2 and
3 are more intensive applications of the same strategy to obtain greater
erosion control.
Marginal cost will be defined here to refer to the addition to total cost
that reflects a higher level of erosion control. Thus, the marginal cost of
Alternative 1 is $50,000, or the "additional" cost of obtaining 4 percent
system effectiveness. For Alternative 2, the marginal cost is $250,000
($300,000 - $50,000) and for 3 it is $1,800,000.
Marginal effectiveness is calculated in the same fashion. For the first
three alternatives, the marginal effectiveness values are all a constant 4
percent.
The marginal value for each strategy must be calculated in the same manner.
Analysis and Choice;
Step 6. Determine Cost-Effectiveness Ratios
To determine the most cost-effective program based upon a desired level of
erosion-control effectiveness, the alternatives should be ranked in order of
increasing marginal cost-effectiveness ratios (see Table 23). The marginal
cost-effectiveness ratio is the quotient of the marginal cost and marginal
effectiveness values.
Analysis and Choice;
Step 7. Rank Alternatives In Order of Cost-Effectiveness Ratios
Based upon these ratios, the alternatives for this example have been ranked
in increasing order and are shown In Table 24. (See also Step 5B of Example
1.)
98
-------
TABLE 24. ALTERNATIVE RANKINGS
Step 7
Rank
1.
2.*a.
b.
3.
4.
5.
6.
7.
8.
9.
10.
11. *a.
b.
12.
13.
A 1 ternati ve
1
4
13
10
5
14
2
11
15
7
8
6
9
3
12
Marg ina
Cost
(X1000)
50
45
75
175
105
300
250
525
500
100
50
450
50
1500
3850
Cost
I Total Cost
Cumu I at? ve
(X1000)
50
95
170
345
450
750
1000
1525
2025
2125
2175
2625
2775
4275
8125
EFE
Marginal
Effectiveness
4
3
5
7
3
5
4
7
5
1
1
3
1
4
7
Step 8
Cumu I ati ve
System
Effectiveness
4
7
12
19
22
27
31
38
43
44
45
48
49
53
60
*At this rank, two alternatives have the same marginal ratio.
99
-------
Analysis and Choice:
Step 8. Determine Cumulative System Effectiveness
Once alternatives have been ranked (Step 1, Table 24 above), cumulative
system effectiveness must be determined. These values are obtained by adding
together the marginal effectiveness values (Table 24 above) for each of the
alternatives with higher ranking. For example, Alternative 5 has a cumulative
system effectiveness of 22, or the sum of values of all the alternatives
ranked above it (i.e., 4 + 3 + 5 + 7 + 3 = 22).
Analysis and Choice:
Step 9. Determine Program that Meets Desired Level of Effectiveness
To determine the program that will meet a desired level of effectiveness,
such as the 25-percent level specified in the objective, reference is made to
the Table 22. A system effectiveness of 27 percent can be obtained by
utilizing the alternatives with the first five rankings. This includes
Alternatives 1, 4, 13, 10, 5, and 14. The program, composed of alternatives
relating to levels of intensity for strategies, is:
Alternatives Strategy intensity Area ^^
1 Low Mountains—Yellow pine
5 Medium Mountains—Virginia Pfne
10 Low Piedmont—Lob loI Iy-Short leaf
14 Medium Piedmont—Oak-Hickory
The reason Alternatives 4 and 13 do not appear in the above tabulation is
that they are included in Alternatives 5 and 14 (5 refers to an alternative
which is a medium level intensity application of strategy 2—simply an
extension of Alternative 4, and similarly for Alternatives 13 and 14). This
program would be approximately 27 percent effective for controlling erosion
100
-------
within the river basin at a total cost of $750,000.
Using similar logic, to obtain a 45-percent level of effectiveness, the
most cost-effective program would be:
Alternative Strategy intensity Area
2
5
8
11
15
Med i urn
Medium
Med ium
Med ium
High
Mountain — Yellow pine
Mountain — Virginia pine
Mounta in — Oak-H i ckory
Piedmont — Loblol ly-
Shortleaf
P i edmont — Oak-H i ckory
This program would be approximately 45 percent effective and cost $2,175,000
annua My.
To show how responsive program costs are to increasing levels of erosion
control, Figure 20 was developed from Table 24. It illustrates how the higher
levels of control are increasingly more expensive. The figure also shows that
by implementing all strategies at their highest level of effectiveness, a
maximum of 60 percent of the expected erosion could be controlled in any year.
101
-------
$8.000 -
7.000 J
6.000 J
5,0004
£ 4.000 -|
o
s
5
» 3.000-1
2.000 J
1,000 J
10 15 20 25 30 35 40 45 50
Percent level of syitem effectiveness
Figure 20. Program costs.
To conclude this example, one major limitation should be noted. The total
costs associated with the various levels of effectiveness embodied in the
alternative programs are the costs only for controlling erosion. This
analysis was conducted investigating silviculture on a regional basis—in a
region where silviculture may comprise a significant segment of the economy.
Evaluating only the incremental costs of erosion control does not account for
economic ram if feat tons throughout the rest of the economy—changes in the
relative prices of wood products, improved efficiency in production, or
employment changes, for example. These Impacts can only be estimated by using
a general equilibrium model. Even so, cost-effectiveness analysis provides a
good evaluation of on-site costs.
102
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REFERENCES
ARINC Research Corporation. 1970. Reviewers' guide for cost-
effectiveness analysis study. J_n_ USDA For. Serv., Manage. Notes
33:13-22. [Originally from Guidebooks for systems analysis/cost-
effectiveness. 1969. This guidebook was produced for the U. S. Army
Electronic Command, Fort Manmouth, New Jersey, and was written under
contract by the ARINC Research Corporation.3
Backer, Morton and Lyle Jacobson. 1964. Cost accounting: a managerial
approach. 678 p. McGraw-Hill Book Co., New York.
Bailey, Robert G. [In press.] Ecoregion descriptions (to accompany map
of ecoregions of the United States). USDA For. Serv,, Ogden, Utah.
Bailey, Robert G. 1976. Ecoregions of the United States, {One-page
map). USDA For. Serv., Ogden, Utah. [In cooperation with the USDA Fish
and WlIdlife Serv.]
Bannock, G., R. E. Baxter, and R. Rees. 1972. A dictionary of economics
427 p. Penguin Books, Ltd., Middlesex, Engl.
Committee for Economic Development. 1971. Improving federal program
performance. 86 p. Res. and Policy Comm., Comm. Econ. Anal., New York.
Ford-Robertson, F. C., ed. 1971. Terminology of forest science, technology,
practice and products. 349 p. Soc. Am. For., Wash., D. C.
Haveman, Robert H., and Julius Margolis, eds. 1977. Puu'ic expenditures
and policy analysis. 2d. ed. 612 p. Rand-McNally P. j!. Co., Chicago.
103
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Kazanowski, A. D. 1968. A standardized approach to cost-effectiveness
evaluations, p. 113-150. J_n_ Cost-effectiveness: the economic
evaluation of engineered systems. J. Morley English, ed. John Wiley and
Sons, New York.
Kemper, Robert E., and Lawrence S. Davis. 1976. Costs of environmental
constraints on timber harvesting and regeneration. J. For. 74(11):
754-761 .
Schwarz, Charles F., Edward C. Thor, and Gary H. Eisner. 1976. Wildtand
planning glossary. USDA For. Serv. Gen. Tech. Rep. PSW-13. 252 p. USDA
For. Serv., Pacific Southwest For. and Range Exp. Stn., Berkeley, Calif.
Soc. Am. For. 1958. Forestery terminology: a glossary of technical terms
used in forestry. 3d. ed. 97 p. Soc. Am. For., Washington.
U. S. Environmental Protection Agency, Region X. 1976. Forest harvest,
residue treatment, reforestation and protection of water quality. EPA
910/9-76-020. 273 p.
U. S. Environmental Protection Agency and USDA Forest Service. 1977.
Non-point water quality modeling in wildland management: a
state-of-the-art assessment (vol. 1—text). EPA-600/3-77-036. 146 p.
Washington Operations Research CounciI . 1967. Cost-effectiveness
analysis: new approaches in decision-making. T. A. Goldman, ed. 23! p.
Praeger Publishers, New York.
104
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BIBLIOGRAPHY
Ashraf, Muhammad, and Robert L. Christensen. 1974. Economic costs of
water quality protection on dairy farms. Water Resour. Bull.
10(2):318-327.
Conn, Elchanan. 1972. Public expenditure analysis with special
reference to human resources. 157 p. Lexington Books, D. C. Heath and
Co., Lexington, Mass.
Crews, James E. I973. Establishing priorities in mine drainage
reduction: a cost-effectiveness approach. Water Resour. Bull.
9(3):567-576.
Jacobs, James J., and John F. Timmons. 1974. An economic analysis of
agricultural land use practices to control water quality. Am. J. Agric.
Econ. 56(4):79l-798.
Jones, J. 0., ed. 1972. Land use planning: the methodology of choice.
47 p. Commonw. Board Agric. Econ., Oxford, Engl.
Krueckeberg, Donald A., and Arthur L. Silvers. 1974. Urban planning
analysis: methods and models. 486 p. John Wiley & Sons, New York.
Little, A. D. 1968. Cost-effectiveness in traffic safety. 167 p.
Praeger Publishers, N. Y.
Miller, W. L., and H. W. Everett. 1975. The economic impact of controlling
non-point pollution in a hardwood forestland. Am. J. Agric. Econ.
5(4):576-583.
105
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O'Connell, Paul F., and Harrey E. Brown. 1972. Use of production functions
to evaluate multiple use treatments or forested watersheds. Water
Resour. Res. 8(5) : 1188-1198 .
Seller, Karl, III. 1969. Introduction to systems cost-effectiveness.
108 p. Wiley-Interscience, New York.
106
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GLOSSARY
Sources for most of the terms defined in this glossary include Bannock,
Baxter, and Reed's A Dictionary of Economics; Ford-Robinson's (editor)
Terminology of Forest Science, Technology Practice and Products; SAP's
Forestry Terminology; and Schwarz, Thor, and Eisner's WiIdland PIanning
Glossary. A few definitions have come from the EPA report, Forest Harvest,
Residue Treatment, Reforestation and Protection of Water Quality.
Aerial logging: See "Logging systems—aerial."
Balloon logging: See "Logging systems—aerial."
Benefit-cost analysis: A technique which attempts to identify and evaluate
the social costs and social benefits of investment projects. The
difference between benefit-cost analysis and ordinary investment
appraisal methods is the stress on the social costs and benefits.
Broadcast burning: Allowing a controlled fire to burn over a designated area
within well-defined boundaries, for reduction of fuel hazard, as a
si Ivicultural treatment following harvesting or thinning, or both.
Broadcast seeding: Sowing over a wide area, especially by hand although this
kind of seeding also includes airplane and helicopter seeding, and
manually operated "cyclone" seeding.
Brush hook: A heavy slashing tool used in much the same way as an axe and
having a wide blade, generally curved.
107
-------
Burning—pile: Commonly referred to as "pile and burn." This involves
piling the slash after lopping and subsequently burning the individual
p!les.
Burning—spot: A modified form of broadcast burning in which only the larger
accumulations of slash are fired and the fire confined to these spots.
Burning—swamper: Otherwise known as progressive burning. This is a burning
of the slash as it is piled.
Cable logging: See "Logging systems—cable logging."
Clearcutting: See "Si Ivicultural practices."
Controlled burn: (1) The planned application of fire to natural fuels,
residue left on a site after a logging operation and other slash, with
the intent to confine it to a predetermined area. (2) Any deliberate
application of fire to an area where control is exercised In some
particular respect.
Cost-effectivesnesS analysis: A comparison of the cost or resource inputs
with the performance of program outputs as they relate to a specific
goali This analysis is used when the benefits of the program are
largely unquantiffable.
Crawler tractor: See "Logging—crawler tractor."
Cross slope: Slope of the road bed.
Cut-and-fi11: The process of earth moving by excavating part of an area and
using the excavated material for adjacent embankments or fill areas.
Cut slope: See "Road structure terms."
108
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Design speed t Speed determined for design and correlation of the physical
features of a road that influence vehical operation. Maximum safe
speed.
Discounting (present value): A method for weighting effectiveness or costs
that occur In future time periods against those that occur in the
immediate future. The relative importance given to future costs or
effectiveness depends upon the discount rate. The discounting
relationship for future costs would be:
where
C(o) = the present value of all future costs
t = the measure of time (months, years)
n = total number of time Intervals
r = the discount rate
Discounting for effectiveness can proceed in the same manner.
Drainage dip: A dip in the road surface which runs at a slight angle to the
cross section of the road, thus allowing water to drain off the road
surface.
efficiency,1 Considered most simply, sconomic efficiency is achieved
When the Value of what is produced by any set of resources exceeds by
as much as possible the value of the resources; or when the least
valuable set of resources Is utilized in producing any particular
worthwht le output k
109
-------
tconomic suboptimization: As used in the text, it refers to the possibility
for calculating a least-cost solution which, when compared with
benefits, may not be truly efficient.
End hauling: Hauling of excavated material (dirt) from a "cut" area to a
"filI" area.
Erosion, accelerated: Erosion much more rapid than normal erosion, natural
erosion or geologic erosion, and occurring primarily as a result of the
influence of the activities of man, or in some cases, of other animals
or natural catastrophes that expose bare surfaces.
Even-aged management: The actions that will result in a forest, crop, or
stand composed of trees having no or relatively small differences in
age.
Even-aged stand: A forest stand composed of trees having no, or relatively
small, differences in age. By convention the maximum difference
admissible is generally 10 to 20 years, though with rotations of less
than 100 years differences up to 25 percent of the rotation period may
be admissible.
Fill slope: See "Road structure terms."
Ground lead: "See Logging, ground lead."
Harvesting practices: In this report, specifically in the ecoregion
tables, this term is used to mean cutting systems. The systems are
clearcutting, seed tree, selection, and shelterwood.
High lead: "See "Logging, high lead."
Insloped surface: See "Road structure terms."
1 10
-------
Intermediate cultural treatments: See "Intermediate cutting."
Intermediate cutting: -Any removal of trees from a regular crop or stand
between the time of its formation and the harvest cutting.
Internal rate of return: That rate of interest which, when used to discount
cash flows associated with an investment project, reduces its net
present value to zero.
InterpI anting: Setting young trees among existing forest growth, planted
or natural. May include the planting of land partly occupied by
brushwood or scrub.
Jammer: There are many kinds of high lead equipment—portable steel towers,
mobile shovel yarders or mobile loggers which are track mounted, and the
jammer—either track or wheel mounted and equipped with a steel or wood
boom. These units come with either a one- or a two-drum winch. Jammer
logging is limited to uphill yarding of clearcuts.
Logging—crawler tractor: Used for logging and normally equipped with a
winch and wire rope. When yarding on steep, swampy, rocky or difficult
terrain, the tractor can be located on stable terrain, and the winch
used to skid logs a short distance to the tractor. Various attachments,
primarily arches and sulkies, have been developed for tractors which
reduce the degree of contact between log and ground.
Logging, ground-lead (low-lead cable logging): A method for transporting
logs from the stumps to a collecting point by dragging them along the
ground with a powered cable passing through a block fastened close to
ground level.
Logging, high-lead: A method for transporting logs from the stumps to a
collecting point by using a powered cable, passing through a block
fastened high off the ground, to lift the front end of the logs clear of
the ground while dragging them.
1 1 1
-------
Logging—rubber-tired skidder: A tractor developed during the 1950's
specifically for logging, Rubber-tired wheel skidders have the
advantage of greater speed over crawler tractors, but the disadvantage
of Iimited traction.
Logging systems:
LOGGING SYSTEMS WITH
OPTIMUM YARDING DISTANCES
ANDSLQPe
(From EPA Report 010/9-76-020,
adapted from USFS Qlosaary
of Cable Logging Terms, 1969)
12
-------
Logging systems—aerial: A system for hauling timber from the stump to a
collecting point which employs aerial means of transportation—e.g.,
balloons or helicopters.
Logging systems—balloon; See "Logging systems—aerial."
Logging systems—cab|e logging: Cable systems are designed to yard logs
from the felling site by a machine equipped with multiple winches
commonly called a yarder. Cable logging is highly efficient for logging
steep rough ground on which tractors cannot operate. Some cable systems
can operate in any direction upslope, downslope, and along the contour.
Cable systems could be classified as either high lead, skyline and
balloon.
Logging systems—full suspension: See "Logging sysfems-v-skyl ine" and
"Logging systems—aerial."
Logging systems—?skyIine: "Skyline logging" is a particular type of cable
'ogglng. A method for transporting logs from stumps to collecting
points that uses a heavy cable stretched between high points (such as in
tall trees braced with guy lines) to function as an overhead track for a
load carrying trolley. Logs are lifted up by cables pr other devices
attached to the trolley and powered pables are used to move the load
back and forth along the main cable.
Lop and scatter: Lopping the slash created by primary conversion and
spreading it more or less evenly over the ground without burning.
Primary conversion is the first stage of converting timber Into any kind
of product. It comprises the tppping, trimming, laying off, baring,
cross-cutting, and Initial sawing up, hewing, pr cleaving of a felled or
fa I I en tree.
Lopping: Chopping branches, tops, and small trees after felling, into
lengths such that the resultant slash will Iie c|psg to the ground.
113
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Mass movement: Downslope, unit movement of a portion of the land's
surface—i.e., a single landslide or the gradual simultaneous, downhill
movement of the whole mass of loose earth material on a slope face.
Mass-wasting: A general term for any of the variety of processes by which
large masses of earth material are moved downs lope by gravitational
forces—either slowly or quickly.
Outs I oped surface: See "Road structure terms".
Partial equilibrium analysis: The analysis of the determination of
equilibrium conditions for a small part of the economy.
Regeneration—artificial: Artificial reproduction is obtained either by
planting young trees or by applying seed, sometimes called "direct
seeding."
Regeneration cutting: (1) Any removal of trees Intended to assist
regeneration already present or to make regeneation possible. (2)
"Regeneration cutting" applies generally to the logging stands of
rotation age or greater, and stands below rotation age which cannot
economically be held any longer because of poor stocking, health,
thrift, quality, or composition. (3) "Regeneration cutting" applies to
a I I cutting in virgin stands and to a I I cutting in cutover stands where
the overwood components of the stand are over rotation age.
Regeneration—natural: Natural regeneration is obtained from seedlings which
originate by natural seeding or from sprouts. Natural regeneration
following harvesting requires a source of viable seed. Seedbed
preparation for natural regeneration Is often accomplished by logging
and slash disposal. However, in many cases deliberately-planned
additional site preparation work Is also needed.
114
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Release cutting: (1) Freeing a tree, or group of trees, from more immediate
competition by cutting, or otherwise eliminating, growth that is
overtopping or closely surrounding them. (2) Three principal operations
come under this classification: (a) Treatments to free desired growing
stock trees from over-story vegetation; principally, scrub trees, brush,
and vines that inhibit their growth or desirable development, (b)
Treatments to prevent development of brush and trees that threaten to
overtop desired growing stock trees, (c) Removal cf grass, weeds, or
brush from around individual seedlings or small trees to release them
from competition for soil moisture, shade, or smothering as under matted
grass or weeds. (3) Cutting an immature stand to free the crop trees
from excessive competition by removing the excess of an undesired age
class (such as a young age class which because of excessive numbers is
competing severely with an older but desired regulated age class).
Road structure terms:
'/VQ
ROADBED
THRU CUT
THRU CUT SECTION
THRU CUT
OUTSLOPED 1-LANE ROAD
THRU FILL
ROADBED
THRU FILL
THRU FILL SECTION
INSLOPED 1-LANE ROAD
1 15
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Rubbei—tired skidder: See "Logging—rubber-tired skidder."
Scalping: Paring off low and surface vegetation, together with most of its
roots, to expose a weed-free soil surface, generally preparatory to
sowing or planting thereon. Done in spots only.
Scarification: To break up the surface of the topsoiI In order to expose
mineral soil.
Sediment: Solid material, both mineral and organic, that Is in suspension,
is being transported, or has been moved from Its site of origin by air,
water, gravity, or ice and has come to rest on the earth's surface
either above or below sea level.
Seed tree: See "Si I vicultural practices—seed tree.'1
Selection: See "SiIvicuItural practices—selection,"
Shelterwood: See "Si IvicuItural practices—shelterwood."
Silviculture: Generally, the science and art of cultivating (i.e., growing
and tending) and managing forest crops for profit based on a knowledge
of si I vies. More particularly, the theory and practice of controlling
the establishment, composition, constitution, and growth of forests.
Si Iviculture—"dearoutting: (I) Removal of virtually all the trees, large or
small, in a stand in one cutting operation. This is the meaning of
"clegrcutting" In its narrowest sense and in Its usage as a technical
term of silviculture, The true elearcutting method lays bare the area
treated and leads to, the establishment of an even-aged stand. (2) The
term "elearcutting" is also loosely applied to any type of cutting in
which all the merchgntable timber is cut and all trees that cannot be
utilized profitably are left, This broader usage of the term Is
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technically incorrect but is so common that it is sometimes prudent to
speak of clear-cutting in the si Ivicultural method sense as "complete
clear-cutting."
Silviculture—clear-cutting system: A si IvicuItural system in which all the
trees are cleared over a considerable area at one time. Regeneration is
generally artificial, but natural regeneration is sometimes possible by
seeding from the air, from adjacent stands, or from seed and/or the
ground.
SiIviculture—seed tree: (I) A tree purposely left standing at the time of
cutting in a forest, for the purpose of producing seed for regeneration
of trees in the cut-over area. (2) A tree selected, and often reserved,
to be a source of seed for collection.
Si IvicuIture--seed tree system: (1) Removal in one cut of the mature timber
from an area, save for a small number of seed bearers left singly or in
small groups. (2) A regeneration cutting where the planned source of
the new stand is from seed existing on, or to be produced by, trees
standing on the cut-over area. The cutting removes all the mature
timber except for the number of seed trees which are needed to provide
seed for reproducing the stand.
A cutting which leaves the number of seed trees needed to provide the
optimum amount of seed required to restock, but not overstock, the area.
Silviculture-deselection cutting: Removal of mature timber, usually the
oldest or largest trees, either as single scattered trees or small
groups at relatively short intervals, commonly 5 to 20 years, repeated
indefinitely, by means of which the continuous establishment of natural
reproduction Is encouraged and an uneven-aged stand is maintained.
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Silviculture—selection system: An uneven-aged si IvicuItural system in
which trees are removed individually, here and there, from a large area
each year. Regeneration is mainly natural and the timber crop ideally
alI different ages.
Silviculture—shelterwood cutting: Cutting which leaves enough trees to
provide about half shade or more on the ground. In some places, more
trees than are needed to provide shade for reproduction must be left in
order to prevent wlndthrow.
Silviculture—shelterwood system: Even-aged si Ivicultural systems in which
(in order to provide a source of seed and/or protection for regenera-
tion) the old crop is removed in two or more successive "shelterwood
cuttings," the first of which is ordinarily the seed tree cutting and
the last is the final cutting, any intervening cuttings being termed
removal cuttings.
Skidding: A loose term for hauling loads by sliding, not on wheels. A
timber may slide more or less wholly along the ground (ground skidding);
or with its forward end supported (high-load skidding); or even wholly
off the ground—sliding along a cable—during its main transit (aerial
skidding).
Skyline logging: See "Logging systems—sky Iine."
Slash: The residue left on the ground after timber cutting and/or
accumulating there as a result of storm, fire or other damage. It
includes unutilized logs, uprooted stumps, broken or uprooted stems,
branches, twigs, leaves, bark, and chips.
Species—associate: Otherwise known as accessory species. A species of less
value than the principal species but sometimes useful In assisting the
development of the latter and liable to influence in some degree the
method of treatment. Both accessory and secondary species are
collectively termed associated species.
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Species—principal: The species to which the silviculture of a mixed forest
is primarily directed, eithei for its (or their) economic or protective
value. Please note, a species intrinsically of higher economic value
than another may be less economically important because of its lower
frequency of occurrence and therefore, not the principal species.
Species—secondary: A species of inferior quality and/or size, and of
relatively little or no si Iv(cultural value, associated with the
principal species.
Tree injection: A deliberate introduction, by pressure or simple absorption,
of a chemical—generally a watei—soluble salt in solution—into the
sapstream of a living tree. Purposes include, to kill the tree or to
prevent or control disease or infestation.
Thinning: Cuttings which are made in immature stands to stimulate growth of
the remaining trees in order to increase the total wood yield.
Thinning—commercial: Commercial thinning Is practiced on older stands for
which the thinned trees have marketable value as pulpwood, poles,
saw logs, etc. The objective of commercial thinning is to provide more
desirable tree spacing and to concentrate growth on the remaining trees
as a means of increasing total yield of wood. It nearly always improves
the general quality of the stand. The age at which stands are thinned
is determined both by tree growth rate and market demand for specific
types of wood products. In contrast to precommercfal thinning,
commercial thinning requires entry into stands with logging equipment
for removal of felled trees.
Thinning—precommercial: The basic objective of precommercial thinning is to
increase merchantable yield by concentrating productivity of the site
into few stems per acre. Such thinning is also valuable for control of
mortality due to insects and disease. Precommercial thinning is
accomplished either with chemicals or by mechcnical methods primarily
powersaws.
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Thru cut: See "Road structure terms."
Thru fill: See "Road structure terms."
Turnout: Double lane section along a single lane road which allows passage
of two vehlcals traveling In opposite directions.
Understory: The trees and other woody species growing under a more or less
continuous cover of branches and foliage formed collectively by the
upper portions of adjacent trees and other woody growth.
Uneven-age management: The course of actions involved in maintaining a
forest or stand, composed of Intermingling trees that differ markedly in
age.
Uneven-aged stand: A forest stand composed of Intermingling trees that
differ markedly in age. By convention^ a minimum range of 10 to 20 years
in generally accepted, though with rotations of less than 100 years, 25
percent of the rotation period may be the minimum.
Water bar: A ridge made across a hill road to divert water to one side.
Yarder: A machine equipped with multiple winches used in the cable logging
system.
Yarding: The operation of hauling timber from the stump to a collecting
point.
YUM yarding (yarding unmerchantable material): A practice of yarding the
larger size classes of residues from recently logged units.
Unmerchantable material is yarded during or following log removal and
piled at the landing. In some instances, especially designed cable
logging systems are used to yard residues.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1 REPORT NO.
EPA-600/8-77-018
3. RECIPIENT'S ACCESSIOr+NO.
4. TITLE ANDSUBTITLE
5 REPORT DATE
Silvicultural Activities and Non-point Polluticjn
Abatement: A Cost-effectiveness Analysis
Procedure
November 1977 issue date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Forest Service
U.S. Department of Agriculture
Washington, DC 20250
10. PROGRAM ELEMENT NO.
1BB770
11. CONTRACT/GRANT NO.
IAG No, EPA-IAG-D6-0660
12 SPONSORING AGENCY NAME AND ADDRESS
Environmental Research Laboratory—Athens, GA
Office of Research and Development
U.S. Environmental Protection Agency
Athens, GA 30605
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/01
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This report focuses upon erosion that contributes to non-point
source pollution occurring in forested environments as a result of silvi
cultural activities. Specifically, the document discusses three topics:
(1) silvicultural practices that are currently being applied throughout
the United States with indications of how these practices may affect the
rate of erosion, (2) a method for determining the cost-effectiveness of
erosion controls that could mitigate or prevent the adverse effects of
silvicultural practices, and (3) examples applying the described method
for economic analysis using information presented in (1). The informa-
tion and outlined method are intended for forest managers and water qual
ity planners to enhance analysis and improve decisions concerning the
reduction of non-point pollution problems.
17.
KEY WORDS AND DOCUMENT ANALYSIS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI F;ield/GrOUp
DESCRIPTORS
Non-point pollution
Silviculture
Costs
Pollution control
48D
68D
98D
3 DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
130
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
121
*U.S. GOVERNMENT PRINTING OFFICE:1978-778-5«9 / 314
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