LAND-COVER/LAND-USE CHANGES IN THE DEREKOLLI CATCHMENT OF THE SOUTH WELO ZONE OF AMHARA REGION, ETHIOPIA

A land-cover analysis carried out in the catchment of Derekolli stream, using image analysis and GIS technologies, in conjunction with data collected through field surveys, revealed two types of changes, i.e., land-cover modification and conversion. The shrubland, which apparently formed the climax vegetation of the study site, and accounted for 16.4 % of the watershed in 1957, disappeared at the rate of 1.6 and 0.31 per cent per year from 1957 to 1986, and from 1986 to 2000, respectively. This change involved a gradual thinning of the shrub and its modification to shrub grassland, and then grassland, due to the selective cutting of the woody biomass for fuelwood and charcoal production. A significant conversion from natural vegetation cover to cropland was observed only between 1957 and 1986, where the cultivated land expanded by 7 per cent. There was very little change in the cropland area since 1986, as most of the land suitable for cultivation was already in use and the limit for expansion had almost been reached. The other type of conversion, i.e., the change from cultivated land to urban area, was insignificant since the land taken up by the emerging town, together with the roads accounted for less than 1.5 per cent of the total area of the catchment. Eastern Africa Social Science Research Review Vol.XVIII(1) 2002: 1-2