Monitoring land cover dynamics in Sub-Saharan Africa: a Pilot Study using Earth Observing Satellite Data from 1975 and 2000
human welfare (Foley et al. 2005). In many developing countries populations are heavily dependant on freshwater, forests croplands and fisheries (Homer-Dixon and Blitt 1998) to which we should add pastures. Shortages in these sectors can give rise to increased poverty, environmental refugees (Jacobson, 1988) and even conflict. Some authorities have even suggested a new age of insecurity (HomerDixon, 1991 ), the so-called “neo-Malthusian” theory. There is a growing body of literature on environmental scarcity and conflict (Raleigh and Urdal, 2005, Urdal, 2005) which reflects not only current concerns but that of future scenarios based on climate change prediction and its subsequent impact on water resources, land degradation and food production. Just how much land cover change has occurred over the last 25 years is not entirely clear – as reliable statistics are hard to come by (see section 1.3). Our study aims to use an independent method to quantify the areal extent of four broad land cover classes: forests, natural non-forest vegetation, agriculture and barren areas, at two key dates 1975 and 2000. We hope to demonstrate that such an approach can give consistent and repeatable results for natural resource assessment, valid at sub continental levels, and propose improvements to the methodology. Due to the limited availability of satellite data our study does not cover ‘desertification’ processes, which require multi-temporal analysis so as to remove possible seasonal and inter-annual effects.
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