As stated by many authors in the recent past, soil erosion is one of the major environmental problems in southern Africa and it will become even more severe in the future due to population growth and potential climatic changes. This study concerns the detection of different land degradation stages in semi-arid grassland areas in the upper Mbuluzi-river catchment (Kingdom of Swaziland). It has been carried out within the framework of an interdisciplinary EU-funded project aimed at developing an integrated water resources management system (IWRMS) for water resources analyses and prognostic scenario planning in semi-arid catchments of Southern Africa. Keywords: remote sensing, degradation, erosion modelling, Swaziland.