Relative Risk to Communities from Wildland Fire of Idaho
Summary
For this analysis, it was assumed that a relative measure of the risks to communities from wildland fire could be characterized by integrating relative wildland fire risk, relative wildland fire hazard, and wildland urban interface. That is, within the wildland urban interface, risks are directly associated with the probability that an area will burn, as well as the likely fire behavior that would occur if that area did in fact burn. It was assumed that burn probability and likely fire behavior would contribute equally to the risks to communities. Agriculture, rock, urban, and water were not assigned a burn probability or relative fire behavior. Consequently, by definition, communities within these cover classes would not be at risk [...]
Summary
For this analysis, it was assumed that a relative measure of the risks to communities from wildland fire could be characterized by integrating relative wildland fire risk, relative wildland fire hazard, and wildland urban interface. That is, within the wildland urban interface, risks are directly associated with the probability that an area will burn, as well as the likely fire behavior that would occur if that area did in fact burn. It was assumed that burn probability and likely fire behavior would contribute equally to the risks to communities. Agriculture, rock, urban, and water were not assigned a burn probability or relative fire behavior. Consequently, by definition, communities within these cover classes would not be at risk from wildland fires. For those communities occurring within burnable areas, a community’s risk to wildland fire could be characterized as follows: CAR = (WUI + Relative WildlandFireRiskstd + Relative WildlandFireHazardstd)/3 Using the three components mentioned above, RelFireRiskCommunities_ID_BLM, "Relative Risk to Communities from Wildland Fire in Idaho" was derived.
These data were designed to characterize mid-scale patterns across Idaho of the the risks of wildland fire to communities. They were developed specifically for use in characterizing relative wildland fire hazard which was then used to assess the risks of wildland fire to communities. This dataset was used in the "Idaho Interagency Assessment of Wildland Fire Risk to Communities, 2007", Map 2 . It was created for the Statewide Interagency National Fire Plan Working Group to which the Bureau of Land Management (BLM), Idaho is a member. It has also been used in other BLM planning efforts such as Resource Management Plans, Fire Management Plans, and NEPA analysis. These data were designed to characterize mid-scale patterns of the risk of wildland fire to communities for regional and subregional assessments. The data were intended to be used for prioritizing subwatershed for fuel treatment projects across the state of Idaho. GENERAL LIMITATIONS These data were designed to characterize mid-scale patterns across the state of Idaho at a scale of approximately 1:100,000. The use of these data at scales less than 1:100,000 is not recommended without field verification. The expected accuracy of these data does not warrant its use for geographic extents smaller than approximately 10,000 acres. That is, these data were not designed to be used for "project level" assessments that typically require 1:24,000 scale data.