The current state and future projections of the fire weather risk in western Iberian Peninsula

Abstract

The study aims to know the current state of the fire weather risk and its tendency for the future based on climate projections over four areas in the western Iberian Peninsula. In order to reach this goal, the Fire Weather Index (FWI) has been considered with a temporal coverage from 1979 to the present derived from the ERA5 reanalysis dataset. Regarding future FWI projections, the dataset was derived from regional climate models developed under the EURO-CORDEX initiative. Initially, the data of the historical period of 40 years were considered (ERA5_HIS), and then the current climate projections until 2098 and for the RCP4.5 scenario. The mean of all the models (called Multi-Model) was used, as well as the historical period from 1970 to 2005 (MMM_HIS), and the projections considering the period from 2006 to 2098 (MMM_PRO). The results show a fire weather risk positive trend in all areas and, in general, there is an increase in the frequency of years with extreme FWI values. The historical model values correlate well with the ERA5_HIS values, however, the MMM_HIS does not represent the extreme years observed in the ERA5_HIS. Looking at the MMM_PRO data, there is a positive trend for the FWI until the end of the century, well above the MMM_HIS. Also, the density plot of FWI values for each scenario (historical, 2021-2060, and 2061-2098) showed that the FWI values are shifted to the right in relation to the historical data, confirming that there is an increase in fire weather risk for the 2021-2060 and 2061-2098 scenarios in all areas considered in the study.