United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/S7-89/010b/c Dec. 1990
SEPA Project Summary
The 1985 NAPAP Emissions
Inventory: Development of
Spatial Allocation Factors
Lysa G. Modica and Daniel R. Dulleba
This report documents the develop-
ment and application of the spatial
allocation factors for the 1985 National
Acid Precipitation Assessment Program
(NAPAP) Emissions Inventory (Version
2). The 1985 annual inventory and related
modelers' inventory represent the most
comprehensive and highest quality
emissions data available. The inventory
spans the 48 contiguous United States
and 10 Canadian provinces. Emissions
data are included for 9,175 plants and
area source categories from 3,073 coun-
ties in the U.S. and the 10 Canadian
provinces. One application of the NAPAP
inventory is to provide an emissions data
input file for regional atmospheric models
used to simulate the transport and
transformation of acid deposition pre-
cursors and the patterns and magnitudes
of deposition products. Annual emissions
data were resolved into a consistent
spatial grid pattern, into hourly values for
12 representative day types and into 59
pollutant species for modeling applica-
tions. This report discusses the develop-
ment of the spatial allocation factors that
were used to distribute county and
province level area source emissions
estimates to a grid pattern defined by
1/6-degree latitude and 1/4-degree lon-
gitude covering the contiguous U.S. and
Canada to 60 degrees north latitude. The
report also documents the computer
software used to formulate the spatial
allocation factors. These factors were
implemented in a modular computer
program known as the Flexible Regional
Emissions Data System (FREDS).
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
The 1985 NAPAP Emissions Inventory
(Version 2) has been developed by the
NAPAP Task Group on Emissions and
Controls. One purpose of the inventory
is to support NAPAP and other research
efforts by providing a high quality model-
ers' emissions inventory that can be used
as input for regional modeling applica-
tions. The emissions inventory was
developed principally for application to
the Regional Acid Deposition Model
(RADM); however, it was developed with
resolution suitable for use in other models,
such as the Acid Deposition and Oxidant
Model (ADOM) and the Regional Oxidant
Model (ROM).
The 1985 NAPAP Emissions Inventory
(Version 2) was resolved spatially, tempor-
ally, and by pollutant species to support
these models. Spatial, temporal, and
species allocation factors were devel-
oped and applied to create the modelers'
inventory. Spatial allocation factors are
based on statistical representations of the
distribution of surrogate indicators which
can be used to estimate the spatial
distribution of emissions from area source
categories.
The spatial allocation factors applied to
the 1985 NAPAP Emissions Inventory
were based largely on factors and meth-
odologies developed for the 1980 NAPAP
Emissions Inventory. The additional effort
completed for the 1985 Inventory devel-
Printed on Recycled Paper
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opment resulted from quality assurance
(QA) and quality control (QC) procedures
that identified problems and errors in the
1980 spatial factors. Details of the QC
procedures and the enhancements to
spatial factors that resulted from the QC
program are also described In the report.
Spatial Factor Overview
The spatial allocation factors were
compiled in a data file which describes
the fraction of the county or province level
totals of each of the surrogate indicators
that are included in each Inventory grid
cell. The spatial allocation surrogate
indicators applied to the 1985 NAPAP
Inventory are summarized in Table 1. Data
reported at various levels of geographic
coverage were used to derive the spatial
allocation factors. In each case, the level
of resolution of the spatial indicators was
modified to be relative to the county or
province level, to be consistent with the
level of resolution of the emissions
estimates.
The development and application of the
spatial allocation factors for the U.S. and
Canada are discussed separately, due to
differences in the methodologies used to
prepare and process the spatial allocation
data. The development of U.S. spatial
allocation factors was based on two main
sources of data: U.S. Department of
Commerce, Bureau of the Census, Cen-
sus of Population and Housing, 1980; and
land use/classification data derived from
1972-1973 Landsat satellite imagery and
land use/cover maps. Canadian spatial
factors were based on data supplied to
Environment Canada by Statistics Can-
ada which represent the base year 1981.
Environment Canada supplied data for the
grid cell resolution by province. All data
processing was completed using the EPA
National Computer Center's Sperry UUI
VAC 1100 and the IBM 3090.
Conclusions
The objectives of this project were to
develop and document the software used
to generate the spatial allocation factors
used in the development of the 1985
NAPAP Modelers' Emissions Inventory
(Version 2). The series of computer
programs described in the document
support the spatial resolution require-
ments of regional acid deposition and
photochemical oxidant models. The
information provided in the report will
facilitate the use and interpretation of the
spatial allocation factors by all Inventory
users.
Table 1. Spatial Allocation Surrogates Used in the 1985 NAPAP Emissions Inventory
Surrogate No.
Surrogate Indicator
Source
1
2
3
4
5
6
1
2
3
4
5
6
7
8
U.S. SPATIAL FACTORS
Population
Housing
Urban Land
Agricultural Land
Composite Forest
Land Area
CANADIAN SPATIAL FACTORS
Population
Oil Homes
Gas Homes
Total Homes
Industrial Labor Force
Commercial Labor Force
Agricultural Labor Force
Mining Labor Force
1980 Census
1980 Census
Landsat
Landsat
Landsat
EPA/Alliance
Statistics
Statistics
Statistics
Statistics
Statistics
Statistics
Statistics
Statistics
Canada
Canada
Canada
Canada
Canada
Canada
Canada
Canada
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Lysa G. Modica and Daniel R. Dulleba are with are with Alliance Technologies
Corporation, Bedford, Massachusetts 01730.
R. Lagemann and C. T. Ripberger are the EPA Project Officers (see below).
The complete report consists of paper copy and magnetic tape entitled "The
1985 NAPAP Emissions Inventory: Development of Spatial Allocation
Factors:"
Paper Copy
EPA/600/7-89/01 Ob, (Order No. PB 90-2371731 AS;
Cost: $31.00, subject to change)
Magnetic tape:
EPA/600/7-89/010C, "1985 NAPAP Emissions Inventory
Spatial Allocation Factors") (Order No. PB 90-5041271 AS;
Cost: $340.00, subject to change)
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/600/S7-89/01 Ob/c
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