Emissions Modeling Clearinghouse
Inventories

BACKGROUND

The starting point for development of a modeling inventory is a database of emissions related data, often referred to as the base year inventory (see the National Emissions Inventory web site.) It is important to understand that a spreadsheet containing only the annual emission estimate for the base year would not be sufficiently robust enough data set to support modeling inventory development. Examples of other emissions-related data would be included in the base year inventory are facility information, material types and throughputs, stack parameters, etc. A full list of the parameters required for emissions modeling can be found in the individual source files of the NEI Input Format.

These additional data are needed to support the modeling and end-uses such as analyzing source impacts and assessing the effectiveness of air pollution control strategies. The base year inventory data also typically include fields for coding the emissions-related data. Coding systems are usually keyed to source types and facilitate the extensive manipulation of modeling inventory data. Without coding systems, data manipulation becomes difficult, if not impossible. Coding systems are used to assign appropriate temporal profiles, spatial surrogates, and/or speciation profiles to emission estimates.