Monitoring 25 years of land cover change dynamics in Africa: A sample based remote sensing approach

The study examines the changes in sub-saharan's natural land covet resources for a 25 year period. We assess these changes in four broad land cover classes - forests, natural lion-forest vegetation, agriculture and barren - by using high spatial resolution Earth observing satellites. Two sets of sample Images. one 'historical' targeted at 1975 and a second 'recent' targeted at the year 2000. have been selected through a stratified random sampling technique over the study area. targeting a sampling rate of 1% in each of the strata. The results, presented at eco-region level and aggregated at sub-Saharan level, show a 57% increase in agriculture area at the expense of natural vegetation which has itself decreased by 21% over the period. with nearly 5 million hectares forest and non-forest natural vegetation lost per year. The impacts of these changes on the environment on one site and on the socio-economy on the other site are discussed and possible pressures oil human well being are highlighted. (c) 2008 Elsevier Ltd. All rights reserved