Meteorological conditions and Occurrence of Forest Fires in Portugal (1971-2010)

Abstract

In Portugal, over the last forty years, there has been a significant increase in the number of occurrences of forest fires, as well as the size of the burned area, a situation that causes many environmental and socio-economic damage, gradually leading the country to an alteration / degradation of their forest. Although the genesis of forest fires, mostly correspond to causes of anthropogenic nature, because “the spontaneous development of the fire, although possible, is rare” (Rebelo, 2003: 15), the weather conditions are an integral part of behavior of fires, especially in regions of Mediterranean climate, as is the case of most generality of the mainland, and that they often end up dictating the characteristics of forest fires. For demonstrate, we analyzed the relationship between the occurrence and development of forest fires in Portugal mainland, over a period of forty years, with the existing weather conditions, expressed through the respective values of temperature and relative humidity of the air and the precipitation , and the results clearly point to a high correlation between certain types of weather and high values of the outbreak and spread of fires, in the same way that other types of time prove to be extremely harmful to the manifestation and development of fire.