Wildland Urban Intermix areas, California

Wildland Urban Intermix
This layer contains polygon features of urban intermix zones. This zone (WUI) is an area where human habitation is mixed with areas of flammable wildland vegetation. It extends out from the edge of developed private land into Federal, private, and State jurisdictions.

Abstract from CDF-FRAP wui03_1 grid layer:
These data describe relative risk to areas of significant population density from wildfire by intersecting residential housing unit density with proximate fire threat to give a relative measure of potential loss of structures and threats to public safety from wildfire. These data are consistent with general National Fire Plan ideals, but is more refined both in terms of mapping extent and in terms of quantification of risk. Within California, both wildfire risk and asset characteristics can vary in the same area. To account for these multiple combinations, spatial data is used to distinguish fire-related characteristics from assets, and spatial rules are applied for determining relative risk of loss (see the Assessment document Assessment Information Systems ).