1 Use of GIS and GPS as a QA Tool in Emission Inventory

Spatial data is increasingly important in emission inventories. Over the last 5 years, the Internet, public “right to know”, and environmental justice programs have greatly increased the visibility and use of emission inventory data. The increased visibility of inventory data in turn increases the need for accurate spatial inventory data. Geographic information systems (GIS) and global positioning system (GPS) technologies are invaluable tools that can be used by state and local government agencies to address spatial deficiencies of inventory data. This study addresses the spatial quality of large point source data. For the 1999 inventory year, large point sources accounted for 8.5 % of NOx emissions and 9.5 % of Reactive Organic Gas (ROG) emissions in California. One GIS technology, address matching, can be used to assess the accuracy of point source coordinate data. The spatial data quality of a subset of point sources in the California Air Resources Board’s tabular California Emission Inventory Data and Reporting System (CEIDARS) was analyzed using geographic information systems. The reported coordinates of point sources were compared with coordinates determined by address matching the street address of the point source. The accuracy of reported coordinates varied widely. The net emission impact of these point sources on neighborhoods can be significant