- Metric Name:  Probability of High Fire Severity

- Data Vintage:  2022

- Unit Of Measure: Probability, 0 to 1

These metrics depicts the probability of high severity fire as constructed by Pyrologix LLC. This operational-control probability raster indicates the probability that the headfire flame length in each pixel will exceed 8 foot flame lengths, the threshold that defines fires that would exceed manual control.

Creation Method: Probability of High Fire Severity (defined as >8 ft) was produced by Pyrologix LLC, a wildfire threat assessment research firm, as part of a spatial wildfire hazard assessment across all land ownerships for the state of California. The ongoing work generally follows the framework outlined in Scott and Thompson (2013), with custom methods and significant improvements developed by Pyrologix. The project generally consists of three components: fuelscape calibration and updates, wildfire hazard assessment, and risk assessment. To date, this work has resulted in a wide variety of spatial data layers related to wildfire hazard and risk, including operational control probabilities based on conditions prior to the 2020, 2021 and 2022 fire seasons. Work to date has been funded by the USDA Forest Service Region 5, the California Energy Commission, and the USDI Bureau of Land Management with data contributions from CAL FIRE. Please reference the Pyrologix 2021 project report (Volger et al., 2021) for more information.

Pyrologix uses the Wildfire Exposure Simulation Tool (WildEST) to develop this data layer, a deterministic wildfire modeling tool that integrates variable weather input variables and weights them based on how they will likely be realized on the landscape. WildEST is more robust than the stochastic intensity values developed with FSim. This is especially true in low wildfire occurrence areas where predicted intensity values from FSim are reliant on a very small sample size of potential weather variables.

- Credits:  Pyrologix, LLC

Primary data contact: James Newman (California State BLM Office) jnewman@blm.gov. This 2022 dataset is an update produced by Pyrologix (pyrologix.com) for the Bureau of Land Management (BLM) California State Office. The original 2020 dataset was developed by Pyrologix for the USFS Pacific Southwest Region. Scott, Joe H.; Thompson, Matthew P.; Calkin, David E. 2013. A wildfire risk assessment framework for land and resource management. Gen. Tech. Rep. RMRS-GTR-315. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 83 p: 
Data disclaimer:  
The user must be aware of data conditions and must ultimately bear responsibility for the appropriate use of the information with respect to possible errors, possible omissions, map scale, data collection methodology, data currency, and other conditions specific to certain data.