Monitoring ten years of fire activity in West and Central Africa

Fire has an important ecological role in many ecosystems worldwide, particularly in the African savannahs where the fire activity is regular and affects large areas every year. In the savannah fires contribute to maintain the balance between the herbaceous and the woody vegetation, and it can also stimulate grass regeneration with positive impacts on the animal community. Fire’s effects can be positive or negative depending on the timing of burning, the rate of fire spread and the environmental conditions where fire occurs. Besides its ecological role fire is also important for many land use practices like farming, agriculture and hunting. Understanding the temporal and spatial patterns of fire is therefore fundamental for an effective land manage-ment, civil protection and natural hazard control as well as for conservation purposes and the sustainable use of natural resources. As study area we chose Central and West Africa because this is a transitional region between the Sahara desert and the humid forests embracing different ecosystems. Our analysis provides information on the fire occurrence and its seasonality which can support fire management and decision makers. We used the MODIS active fire product from the year 2001 to 2011. For each year we considered the period from September to May to include the complete dry season. We arranged fire data in 10-day periods and applied a grid with 0.25 degree cell size. We determined, for each dry season, the number of decades when the first and third quartiles of the cumulative fire pixels were reached. Using this approach we also determined the length of the core fire season as the difference between the first and third quartiles (in decades). Results highlighted regional patterns in the temporal distribution and duration of fires, which were often associated to a change of ecoregion or the land cover type.JRC.H.3-Global environment monitorin