Sierra Nevada U.S. Forest Service (USFS) Wildland Urban Intermix Zones

This dataset depicts Wildland Urban Intermix zones within the Sierra Nevada Forest of Region 5. These Forests include Modoc, Lassen, Plumas, Tahoe, Lake Tahoe Basin Management Unit, Eldorado, Stanislaus, Sierra, Inyo, Sequoia and Toiyabe portion of the Humbolt-Toiyabe of Region 4. 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 http://www.frap.cdf.ca.gov/_assessment/Introductory_Materials/infosystems.html).