Abstract
So much in literature has been reported on the complex nature of desertification processes, and extents, but very little is known about the proportional contribution rate of these processes in a given landscape and hence the ultimate aim of this study. RS/GIS change detection techniques was employed in the landscape change analysis. The natural jenks classification in the spatial analyst tool in ArGIS was used to evaluate and map the landscape sensitivity areas. Twelve specific indicators representing specific processes and effects were analysed and three aggregated to represent four types of landscape; vegetation, soil, hydro-geomorphic and micro-climatic. A total of 8923km2 (29%) of the Vegetation landscape showed either positive or negative changes in vegetation cover. Low sensitivity areas contributed the highest (40.2%), followed by very high (4.6%), moderate (2.6%) and very low (2.5%) of vegetation degradation. 50% of the landscape recorded vegetation degradation while the other 50% recorded regeneration of vegetation. A very large extent (70.5%) of the soil landscape experienced either positive or negative soil changes. Soil degradation was contributed by Moderate (26.4%), High (17.8%, Low (5%) sensitivity landscapes. About 50% of the soil landscape revealed various forms of degradation. Only a small extent of the hydro-geomorphic landscape (7.8%) of the landscape underwent changes either positive (degradation) or negative (recovery). Out of this extent the very high sensitivity class contributed 32.1%, while moderate (14.5%) and Very Low (3.4%) of degradation. The pattern of contributions of changes in extents in the micro-climatic landscape indicated only a small extent of the landscape (9.6%). The high sensitivity landscape alone contributed 31.6% of the areas that observed degradation, followed by very high (10.1%) and Moderate (8.3%), this put together a total of 50% of the landscape recorded degradation.