MULTISPECTRAL REMOTE-SENSING OF BIOMASS BURNING IN WEST-AFRICA

Remote sensing measurements provide a vauable means of determining the extent of burning areas and of estimating the overall distribution of pollutant sources (identified from experimental studies) in time and space. This distribution has to be taken into account in the boundary conditions of chemistry atmospheric models. Recent methods developed f or the remote sensing of active fires in tropical or temperated forest zones, have been found to be completely inadequate for fire detection on West African savannas. In order to accurately estimate the active fire distribution in the function of different sorts of West African s avannas (Sahelian, Sudanian and Guinean) and forests, a multispectral methodology has been developed based on NOAA/11-AVHRR satellite data, with the purpose of eliminating as much as possible the problems relat ed to large surface heterogeneity, confusion and bias, produced by clo uds, smoke, haze, background emissivities, etc. Unlike other methods, the results show that the multispectral method, in spite of its select ivity, provides realistic results, and does not under- or over-estimat e the number of fires that can be sensed by the satellite. Consequentl y, this methodology is more appropriate than the simplest ones for a s ystematic sensing of this phenomenon.