A GENERAL MATHEMATICAL FRAMEWORK FOR MODELING 2-DIMENSIONAL WILDLAND FIRE SPREAD

This work considers the modelling of two dimensional fire spread for h eterogeneous fuel and meteorological conditions. Differential equation s are used as the modelling form, and a set of partial differential eq uations that describes fire growth in terms of the rate of spread at e ach point on the perimeter is derived. These equations require the spe cification of the rate of spread as a function of the variables affect ing it, and form a general modelling framework into which such a funct ion can be placed. To model the relationship between the rate of sprea d and its affecting factors an analysis of point source ignition fires for homogeneous fuel and meteorological conditions is made. Based on this analysis a spread rate model for heterogeneous conditions is prop osed. The resulting differential equations require a sophisticated com puter solution, however there are a number of nontrivial fire situatio ns for which solutions can relatively easily be obtained, and example solutions are presented.