The Western United States (U.S.) is on fire like never before, with over nine million acres burned in 2020 (National Interagency Coordination Center). There are 13 Department of Defense (DoD) and two Department of Energy land holdings in six Western states that are at risk of experiencing devastating wildfires in the coming years. Current fire behavior models are inadequate for predicting fire dynamics in Western shrubland fuel types and discontinuous fuels of the West and many of the fuel breaks being considered for the West have yet to be evaluated in relation to fire behavior models. This multi-agency project will evaluate effectiveness of vegetative features on Western rangelands by conducting a series of test burns that will allow for rigorous and well-documented in-fire measurements. These test burns will evaluate a next generation physics-based fire model. Key objectives are: 1) field test and evaluate the performance of a new physics-based model as it predicts fire behavior in discontinuous fuels; 2) evaluate fuel break performance in relation to the modeled, physical fire spread components of combustion, radiative and convective heat transfer, and fuel particle heat exchange and ignition; 3) engage DoD Western facility range managers in developing technology transfer products to apply the modeled science to their installation fire management; and 4) creation of an Range Commanders Council vetted Range Commanders Guidebook which outlines best management practices and range community initiatives in a comprehensive and science-based framework.

The technology is a physics-based, one-dimensional - fuel particle to fuel particle - model that directly quantifies the interaction among the individual components of fire spread, fuel characteristics including gaps in continuity, and environmental variables. Innovative fire scale and computational speed make it practical for decisions regarding planned discontinuities in vegetative fuels, and specifications for treating fuels on the fireline. The simulation takes seconds to run but represents the key physical processes of fire spread including gaps in the fuel, which are represented explicitly at resolutions of centimeters, no longer requiring the assumption of homogeneous fuel. Thus, the simulation will relate fuel and environmental characteristics in determining spread thresholds as a function of gaps, loading, height, fuel moisture, wind speed, and slope.

This model is critical to the Western states in predicting and understanding fire behavior in discontinuous fuels. Results from the demonstration will guide Defense Department investment in strategically constructed fuel features transferring innovative technology into fire control features in operational range settings. This project represents enormous cost savings and infrastructure protection potential on 13 military facilities in six Western states that represent about seven million acres, or 26% of all continental DoD owned lands and will support investment in fuel treatment best management practices and pre-suppression technology development rather than fire suppression. The tactics techniques and procedures suggested to coordinate within the Office of the Secretary of Defense Range community will show utility throughout the Continental U.S. Range Complex within the U.S.