Investigation of the weather conditions leading to large forest fires in the area around Athens, Greece

Abstract

Large forest fires are of great concern in all fire prone countries. Understanding them and predicting the possibility for their occurrence can be very helpful for forest fire management. They usually occur under very adverse fire weather conditions so any investigation about them is sure to take this into consideration. The Fire Weather Index (FWI) of the Canadian Forest Fire Danger Rating System which enjoys very broad use not only in the vast forests of Canada but also in other parts of the world, is a composite index that represents fire weather conditions quite well. The study presented here is an investigation of the possibility to associate fire weather conditions, as captured by FWI, with the occurrence of large forest fires in the broader area around Athens, the capital of Greece. It is based on forest fire data from the Greek Fire Service for the 2003-2011 period, matched to FWI values for this period, calculated using gridded observation data from the ERA Interim data sets, that were interpolated using the Thin Plate Spline Technique in order to obtain high resolution (1 km) spatial analysis data. Correlations between FWI and burned area per fire proved to be very poor, precluding regression modelling, so an alternative analysis method was used in order to determine, according to the data for the study period, the minimum FWI above which it is possible for fires to exceed certain burned area thresholds.