The fire regime of Senegal and its determinants

Abstract

Biomass burning in Senegal has a range of different causes and affects many different environments. Each cause has a unique spatial and temporal distribution with its own consequences for the fire regime in Senegal. To date, this regime has been only poorly understood due to numerous methodological problems with monitoring fires and mapping their extent. Satellite remote sensing techniques provide the only realistic means of obtaining fire information at the national scale, yet even their use involves considerable problems. This paper uses NOAA AVHRR data from 1989, 90. 91 and 92, supplemented with Landsat and SPOT data, to describe the Senegalese fire regime based on the ‘active fire detection approach’. Possible explanations for the observed patterns will be discussed. The results show that the northern limit of intense fire activity in savannah woodlands can not be adequately explained by variations in rainfall, herbaceous biomass distribution or land cover type. Senegal may be divided into regions characterized by a more or less well-defined pattern of fire occurrences. High frequency of fires, especially early in the dry season, is typical of the savannah woodlands in the east-central part of Senegal. While the central, predominantly agricultural areas experience relatively few fires, areas in the margin of the central ‘Peanut Basin’ have an abundance of fires late in the dry season. In the northern rangelands of the Ferlo few fires occured in the years studied.