Thursday, 15 November 2001: 10:30 AM
Statistical forecasts of western wildfire season severity
The existence of links between seasonal climate anomalies and seasonal fire activity in the Western US motivates a forecast of seasonal acres burned (May to October) on a 1 x 1 degree grid in the western contiguous United States using lagged values of the Palmer Drought Severity Index (PDSI). Many areas contain a characteristic pattern that links fuels to climate-high fire activity tends to occur when the preceding year is moist (positive PDSI) and the concurrent year is dry. These relationships motivate our choice of predictor variables. The forecast model is estimated using Canonical Correlation Analysis (CCA) to calculate linear relationships between principal components of the seasonal acres burned and lagged PDSI data sets. The best model produced cross-validated forecasts for the 1980 to 2000 fire seasons with statistically significant results in one quarter of the grid cells. A forecast, developed retrospectively, for the very active fire season of summer 2000, was fairly successful in reproducing the observed acres burned.