Fuelscape datasets for wildfire risk assessment in the sagebrush biome (270m)

The foundation of quantitative wildfire hazard or risk assessment is a current-condition fuelscape (i.e., fuel and terrain layers), ideally updated to account for recent disturbances and calibrated to reflect the fire behavior potential observed in recent historical wildfire events. This data publication provides the fuelscape generated for a wildfire risk assessment focused on the sagebrush biome of the western United States (US). The data depict ca. 2020 fuel conditions, after customization, to better reflect expected fire behavior in sagebrush ecosystems, including influences from exotic annual grass (e.g., cheatgrass) invasion and conifer (e.g., pinyon, juniper) encroachment. These data are presented as used for biome-wide geospatial fire modeling at a 270-meter resolution. The work was conducted using simulation units called “pyromes,” which represent areas of relatively homogenous contemporary fire regimes. The sagebrush biome is represented by 31 pyromes, covering about 450 million acres in total area. Fuelscapes for the 31 pyromes are included in this data product as separate multiband GeoTIFFs. The bands of each GeoTIFF store eight layers of data that describe terrain (aspect, elevation, slope), tree canopy (cover, height, base height, bulk density), and surface fuel (FBFM40). These data form the Landscape (LCP) file commonly used by US wildland fire behavior modeling systems (e.g., FlamMap, FSPro, FSim). Each fuelscape dataset includes a 30-kilometer buffer to avoid truncating the simulated fires at pyrome boundaries. A shapefile and geopackage containing the boundaries and size of each pyrome are also included.
In the western United States, hundreds of thousands of acres of highly imperiled sagebrush ecosystems are lost or degraded each year as a result of altered wildfire regimes. In response to these wildfire threats, extensive fuel treatment investments have been proposed throughout the region. Regional-scale assessment of wildfire risk offers a consistent means of evaluating threats to valued resources and assets, thereby facilitating the most cost-effective investments in management activities that can mitigate those risks. We used a large-fire simulation system (FSim) to estimate the probabilistic components of wildfire risk across the sagebrush biome, which includes portions of 13 western states. This publication includes the customized fuelscape data used for that fire-modeling work.