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 ------- 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 ------- 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 BULK RATE POSTAGE & FEES PAID EPA PERMIT No. G-35 Official Business Penalty for Private Use $300 EPA/600/S7-89/01 Ob/c ------- |