THE USE OF FRACTAL DIMENSION TO IMPROVE WILDLAND FIRE PERIMETER PREDICTIONS

Fire managers currently use simple elliptical models to predict the pe rimeter of a fire when the fire starts from a single point. However, w hen examined closely wildland fire perimeters are highly irregular. We tested the hypothesis that a fire is actually fractal in nature and t hus the true length of a fire perimeter depends on the amount of fine- edge detail included in the measurement. The amount of perimeter detai l incorporated is dependent on the length of the base unit of measurem ent; the longer the unit, the less the perimeter detail, and the short er the perimeter. Different forest fire suppression techniques have in herent scale characteristics that are associated with different base u nit measurements of perimeter; therefore, the length of the fire perim eter is dependent on the suppression technique used. Analysis of 14 fo rest-fire perimeters yielded a consistent fractal dimension of 1.15, a nd a relationship was found to adjust predicted fire perimeter with th is fractal dimension for a specific unit measurement length. The fract al length of fire fronts between two identifiable points can also be c alculated given the base unit measurement of the suppression technique . This information should improve fire managers' ability to optimally dispatch suppression resources to forest fires.