Uncovering current pyroregions in Italy using wildfire metrics

ELIA, MARIO; GIANNICO, VINCENZO; ASCOLI, DAVIDE; ARGAÑARAZ, JUAN PABLO; D'ESTE, MARINA; SPANO, GIUSEPPINA; LAFORTEZZA, RAFFAELE; SANESI, GIOVANNI

Alghero

Conferencia; III International Conference of Fire Behaviour and Risk; 2022

National Research Council of Italy, Institute of BioEconomy, and University of Sassari

Pyrogeography is a major field of investigation in wildfire science because of its capacity todescribe the spatial and temporal variations of fire disturbance. We propose a systematicpyrogeographic analytical approach to cluster regions on the basis of their pyrosimilarities. Weemployed the Affinity Propagation algorithm to cluster pyroregions using Italian landscape asa test bed and its current wildfire metrics in terms of density, seasonality and stand replacingfire ratio. A discussion follows on how pyrogeography varies according to differences in thehuman, biophysical, socioeconomic, and climatic spheres. The algorithm identified sevendifferent pyroregion clusters. Two main gradients were identified that partly explain thevariability of wildfire metrics observed in the current pyroregions. Firstly, a gradientcharacterized by increasing temperatures and exposure to droughts, which coincides with adecreasing latitude, and secondly, a human pressure gradient displaying increasingpopulation density in areas at lower elevation. These drivers exerted a major influence onwildfire density, burnt area over available fuels and stand replacing, which were associatedto warm-dry climate and high human pressure. The study statistically highlighted theimportance of a North-South gradient, which represents one of the most important drivers ofwildfire regimes resulting from the variations in climatic conditions but showing collinearity withsocioeconomic aspects as well. Our fully replicable analytical approach can be applied atmultiple scales and used for the entire European continent to uncover new and largerpyroregions. This could create a basis for the European Commission to promote innovative andcollaborative funding programs between regions that demonstrate pyrosimilarities.