Soil degradation: Its aspects and modelling a case study of Northeast Nuba Mountain South Kordofan State, Sudan

The study was carried out at Abujubeha area (10? 52 48.17 ‐11? 23 08.79 N and 30? 00 05.99 ‐ 31? 28 04.91’ E) in Northeast Nuba Mountain, South Kordofan region, Sudan. In order to investigate the soil degradation aspects in the study area, its causal, rate per time and mapping; the remote sensing and GIS technologies were used beside the routine soil survey and laboratory analyses. Quantitative information on soils degradation and vegetation cover changes was acquired. Using multi‐spectral satellite imagery the most dynamic land cover types have been able to be mapped with 64% accuracy (Dense Forest, Moderate Forest, Light Forest, Fallow and Bare soils). The result showed that 38% of the forested areas were lost in the last two decades at annual rate of 1.8%. Forest clearance in the last 5 (199‐2005) years equal two times the clearance happened in the previous 15 years (1986‐1999). The geostatistical characterization of soil variability showed that soil properties are highly spatially dependent, with significant sensitivity to soil‐forming factors. Soils dynamic are affected by land use system as well as with soil physiographic position. The Red soils (Gardud) are more dynamic than the Dark clayey soils. The Universal Soil Loss Equation (USLE) was used; the result revealed that the study area is potentially susceptible to be eroded by water. The Erosion rate was measured in term of erosion Risk Assessment. The model indicated that the overall average of soil loss is 1.32 t/ha /y