Utilization of NOAA AVHRR for assessing the determinants of savanna fire distribution in Burkina Faso

Temporal and spatial patterns of active fires, detected using NOAA AVHRR LA C data, in Burkina Faso are identified and related to vegetation, tree cove r and land use classes. Initially, fires are classified into early and late dry season fires (EDSF and LDSF). Early dry season fires are defined as fi res occurring earlier than 45 days after the start of the dry season, marke d by a levelling out in the post-rainy season temperature increase, determi ned on the basis of surface temperature data derived from NOAA AVHRR. The d ate of the start of the dry season, defined in this way, is shown to be a l inear function of the latitude. The distribution of fire occurrence are sho wn to display distinctively different patterns. These distribution patterns are related to information on vegetation class, woody biomass and land use intensity as well as net primary productivity, estimated from NOAA AVHRR r ainy season data. It is shown that overall fire frequency and the ratio of early to late dry season fire activity depend strongly on net primary produ ctivity, land use intensity and vegetation class. Late fires tend to occur mainly in agricultural areas, whereas early fires are much more frequent in areas of low land use intensity in the wooded savannas of southern Burkina Faso.