Aspect was used as a surrogate to characterize areas that are relatively drier, therefor have lower live/dead fuel moistures. If the effects of vegetation are ignored, it was assumed that fuel moisture varies according to aspect. That is, with all else being equal, fuels are typically drier on southwesterly aspects, and moister on northeasterly aspects. Relative fuel moisture was assigned to 3 aspect classes : Azimuth (degrees) Relative Solar Radiation Relative Fuel Moisture 1 to 80; 351 to 360 low high Flat; 81 to 170; 261 to 350 moderate moderate 171 to 260 high low Excluding the effects of real-time weather, fire behavior is dependent upon the structure, composition, and arrangement of fuels; fuel moisture, and slope.These data were designed to characterize mid-scale patterns of relative wildland fire risk across the state of Idaho. 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, 2006", Map 5B. It has also been used in other BLM planning efforts such as Resource Management Plans, Fire Management Plans, and NEPA analysis. 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. Although the resolution of this theme is a 90-m cell, the expected accuracy 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.
