S. Serneels et al., Land cover changes around a major east African wildlife reserve: the Mara Ecosystem (Kenya), INT J REMOT, 22(17), 2001, pp. 3397-3420
The dynamics of savannah vegetation are still poorly understood. This study
aims at analysing land cover changes over the past 20 years in the rangela
nds area of Narok District, Kenya. To analyse the impact of inter-annual cl
imate variability and human activities on land cover modifications in the a
rea, change detection techniques based on remote sensing data at different
spatial and temporal resolutions were used. Coarse spatial, high temporal r
esolution NOAA (National Oceanic and Atmospheric Administration) data were
analysed to investigate the role of inter-annual climate variations on the
ecosystem. A combination of time contextual and spatial contextual change d
etection approaches was used on a set of three high spatial resolution Land
sat images to map land cover modifications over the past 20 years. Both dat
asets are highly complementary in the detection of land cover dynamics. On
the one hand, the coarse spatial resolution data detected areas that are se
nsitive to inter-annual climate fluctuations, but are not subjected to land
cover conversion. On the other hand, the high spatial resolution data allo
wed the detection of land cover conversions or modifications between two co
nsecutive dates that have a more permanent character and are independent of
climate-induced fluctuations in surface attributes.