Space/time characteristics of errors in an integrated weather/fire spread simulation

This study examines the space/time error characteristics of FARSITE fire spread simulations for a fire in San Diego County in June 2002. A high resolution airborne imaging system developed specifically to observe wildland fires provided accurate fire perimeter locations at 10 minute intervals, which we compared to simulated growth for the same time period. We simulated weather conditions affecting the fire using the MM5 model at a horizontal grid spacing of 1.3 km. We defined error in the spread simulation as the ratio of the actual fire area to the simulated fire area in any given sector, and we described the spatial variability of the error by the sector ratios as a function of compass direction, relative to a reference point in the fire's interior. The error analysis provides the basis for fire risk assessment that incorporates uncertainty in fire spread predictions.