Air Resources h4. California Air Resources Board The following datasets are from the California Air Resources Board: * *arb_california_airbasins -* California Air Basins == The California Air Basins layer is a polygon shapefile coverage representing the 15 California air basins, as defined in state statute and regulation. See the California Health and Safety Code, Section 39606 et seq. and California Code of Regulations, Title 17, Section 60100 et seq. Shapefile coverage. This data layer shows the air basin boundaries and their names, as of March 2004. Projection: Teale Albers, NAD83, GRS 1980. == == Air Basins are designated pursuant to California statute and regulation. Air Basins identify regions of similar meteorological and geographic conditions and consideration for political boundary lines, and are related to air pollution and its transport. == * *arb_california_airdistricts* - California Air Districts == The California Air Districts layer is a polygon shapefile coverage representing the California air pollution control and air quality management districts, as defined in federal and state law. See 40 CFR, Chapter I Section 81, et seq., and California Health and Safety Code, Section 40000 et seq. Shapefile coverage. This data layer shows the air district boundaries and their names as of March 2004. Projection: Teale Albers, NAD83, GRS 1980. == == Air Districts are designated pursuant to federal and state statute. Air districts identify the local and regional authorities who have primary responsibility for control of air pollution from sources that are not motor vehicles. (Motor vehicles are the responsibility of the state Air Resources Board.) == * *arb_california_counties_aligned* - California county boundaries == This California county boundaries layer is a shapefile coverage representing the California county boundaries, at moderate spatial resolution, aligned to match well with the ARB California Air Basins and California Air Districts polygon boundary shapefiles. It is not intended to replace more spatially detailed county boundary layers available elsewhere. ==