Wildfire Frequency-Area Statistics in Spain

The term wildfire regime refers to the wildfires characteristics in a given region during a given period of time. Here we examine one aspect of the wildfire regime, burned area frequency-area statistics of wildfires, for different regions of Spain, as defined by climate zones, for the period 1988-2007. We use the EGIF (General Statistics of Wildfires) database from the MARM (Ministry of Environment and Rural and Marine) using the Reports of Wildfires of the Autonomous Communities. An initial exploration of data showed some inconsistency in reporting sizes of fire both spatially and temporally, with in general underreporting of fire sizes below about 1 ha. For the five climatic regions examined, frequency-area statistics showed robust inverse power-laws, with exponents ranging from 1.54 to 1.99. We found that in Spain, lower values tended to correlate with Mediterranean climate regions, and higher values with Oceanic climate region. The use of frequency-area statistics characteristics has allowed us to examining the spatial and temporal variability of the power-law exponents. The characteristics of these values might further inform the complex environmental and human factors that have changed both spatially and temporally in Spain.