Spatial Variability of Wildfire Causes in French Eastern Mediterranean Regions ^†

The study of wildfire’s causes and ignition patterns, which in the Mediterranean area, are mainly directly or indirectly linked to human activities, is essential for designing effective wildfire risks reduction measures and to mitigate the related impacts on ecosystems and livelihoods.

The causes that underlie the ignition pattern vary across the socio-economic and environmental factors. Furthermore, within the same territorial context, wildfire causes are not spatially uniform and often are aggregated in spatio-temporal clusters. This substantially increases the variability of wildfire ignition patterns even within the same territory.

The main difficulty in studying the spatio-temporal distribution of wildfire causes is due to the limited data available and lack of homogeneity in the available databases. However, the detail and reliability of the databases of some countries are better than in the past; for instance, the case of the French database Promethèe (https://www.promethee.com/ accessed on 18 November 2020), which since 2012 classifies wildfire causes with greater detail than in the past.

In this work, using data from the Promethèe database, we investigated the spatial variability and the incidence rate of different wildfire causes in the French Eastern Mediterranean regions PACA (Provence-Alps-Cote d’Azur) and Corse, within the framework of the Italy-France Maritime MED-Star project. For each administrative unit of the European NUTS3 level, the incidence rate of the different wildfire causes was identified. Furthermore, using the DFCI grid, the level of analysis of the fire causes’ spatial variability was further detailed, allowing us to identify the spatial clusters of aggregation of the most frequent causes of wildfires.

This work allowed us to demonstrate and describe the strong spatial variability of wildfire causes, providing a basis for further follow-up studies on wildfire ignition patterns and supporting territorial-specific policies for better contrasting wildfire ignitions.