Spatially explicit forecasts of large wildland fire probability and suppression costs for California

In the last decade, increases in fire activity and suppression expenditures have caused budgetary problems for federal land management agencies. Spatial forecasts of upcoming fire activity and costs have the potential to help reduce expenditures, and increase the efficiency of suppression efforts, by enabling them to focus resources where they have the greatest effect. In this paper, we present statistical models for estimating 1–6 months ahead spatially explicit forecasts of expected numbers, locations and costs of large fires on a 0.1258 grid with vegetation, topography and hydroclimate data used as predictors. As an example, forecasts for California Federal and State protection responsibility are produced for historic dates and compared with recorded fire occurrence and cost data. The results seem promising in that the spatially explicit forecasts of large fire probabilities seem to match the actual occurrence of large fires, with the exception of years with widespread lightning events, which remain elusive. Forecasts of suppression expenditures did seem to differentiate between lowand high-cost fire years. Maps of forecast levels of expenditures provide managers with a spatial representation of where costly fires are most likely to occur. Additionally, the statistical models provide scientists with a tool for evaluating the skill of spatially explicit fire risk products. Additional keywords: fire simulations, generalised Pareto distribution, hydroclimate, logistic regression, moisture deficit, spline functions.