What is a fuel model?

Fuel models are used to classify the vegetation that is susceptible to burn. Each fuel model describes the vegetation properties by numerical parameters:

• Fuel loading - the mass of fuel per unit area, live and dead, grouped by particle size classes.
• Surface area to volume ratio of each size group.
• Fuel depth (m).
• Fuel particle density (kg.m^-3).
• Heat content of fuel (kcal.kg^-1).
• Moisture of extinction - the upper limit of fuel moisture content beyond which the fire will no longer spread with a uniform front.

In the STORMS project we use the fuel models developed by the Northern Forest Fire Laboratory (NFFL) (Rothermel, 1972; Andserson, 1982).

Thirteen different fuel models are available, classified in four major groups: grasses; shrubs; timber, and slash. Within the regional study area, eight NFFL fuel models have been identified.