Sensitivity of fire occurrence to meteorological variables in Mediterranean and Atlantic areas of Spain

Abstract Wildland fires are common in most areas of Spain, even in areas with a mesic climate. Weather plays a crucial role in fire, but the relationship between fire incidence and meteorological variables is not usually strong. Assessing the relationship between meteorological variables and fire from the recent past can eventually aid in evaluating fire risk in future climate scenarios. In this paper we report on the relationships between the number of fires and the surface burned per year and several yearly temperature and precipitation variables for three areas of Spain: North, Central and the Levant. The three areas differ in their climate as well as in the ignition sources. We used the fire records from 1974 to 1988. The relationships between meteorological and fire variables was tested by least square simple regression models. Our results show that some of the meteorological variables used are good predictors of either number of fires or surface burned in all three areas. The northern area was better related to meteorological variables than the Levant. Fire occurence in the northern and central areas was mainly related to temperature variables whereas in the Levant it was related to precipitation variables. Fires caused by pasture burning or by lightning had less relationship to meteorological variables than those caused accidentally. Fires caused by arsonists were very highly related to meteorological variables in all three areas. Fires caused by unknown sources had a similar pattern of relationships to that found for arsonist-caused fires. Our study indicates that the degree of relationship between meteorological variables and fire occurence may be related to the current climate and weather patterns of a given area.