The Fuel Loading Model (FLM) surface fuel classification system characterizes wildland surface fuel. FLMs provide a simple and consistent way for managers to describe onsite fuel for input into fire behavior and effects software. FLMs contain representative loading for each fuel component (e.g., woody and non-woody) for typical vegetation classification systems. They characterize fuel loading across all vegetation and ecological types.
To develop FLM classes, maximum soil surface heating and total PM2.5 emissions were simulated for a large set of surface fuelbeds sampled across the contiguous United States. The simulated effects were then grouped into ten Effects Groups using a statistical clustering routine. Finally, classification tree analysis was used to predict duff, litter, fine woody debris (FWD) and log load that resulted in the soil heating and emissions seen in each of the Effects Groups.
The FLM layer may be used to prioritize fuel treatment areas, evaluate fire hazard and potential status, and examine fuel loading characterizations. It may be used as input into wildland fire simulation software.