County-level analysis of the impact of temperature and population increases on California wildfire data

The extent to which the apparent increase in wildre incidence and burn area inCalifornia from 1990 to 2006 is aected by population and temperature increasesis examined. Using generalized linear models with random eects, we focus onthe estimated impacts of increases in mean daily temperatures and populationsin dierent counties on wildre in those counties, after essentially controlling forthe overall dierences between counties in their overall mean temperatures andpopulations. We nd that temperature increase appears to have a signicant posi-tive impact on both total burn area and number of observed wildres. Populationgrowth appears to have a much less pronounced impact on total burn area thando annual temperature increases, and population growth appears to be negativelycorrelated with the total number of observed wildres. These eects are especiallypronounced in the winter season and in Southern California counties.