Standard Fire Behavior Fuel Models

This report describes a new set of standard fire behavior fuel models for use with Rothermels surface fire spread model and the relationship of the new set to the original set of 13 fire behavior fuel models. To assist with transition to using the new fuel models, a fuel model selection guide, fuel model crosswalk, and set of fuel model photos are provided.

Predicting the potential behavior and effects of wildland fire is an essential task in fire management. Mathematical surface fire behavior and fire effects models and prediction systems are driven in part by fuelbed inputs such as load, bulk density, fuel particle size, heat content, and moisture of extinction. To facilitate use in models and systems, fuelbed inputs have been formulated into fuel models. A fuel model is a set of fuelbed inputs needed by a particular fire behavior or fire effects model. Different kinds of fuel models are used in fire science; this document addresses only fire behavior fuel models for use in the Rothermel (1972) surface fire spread model.

Stylized fuel models, or numerical descriptions of fuel arrays, are used as inputs to fire behavior simulation models. These fuel models are often chosen on the basis of generalized fuel descriptions, which are related to field observations. Site-specific observations of fuels or fire behavior in the field are not readily available or necessary for most fire management planning situations. Fuels are thought of in general terms and a single fuel model is often assigned to represent large areas of land. Variations in weather, which can substantially affect fire behavior, are not reflected in the available aids for selecting fuel models. The sensitivity of simulated fire behavior variables to the 13 fire behavior fuel models and two-fuel-model alternatives was analyzed. The two-fuel-model concept demonstrated the effect of combining fuel models on simulated fire behavior results.

Expands upon the basic concepts of fuel modeling to provide a more complete discussion of the technical details of constructing site-specific fire behavior fuel models.