Estimation of Soil Erosion Risk in Mubi South Watershed, Adamawa State, Nigeria

The study aims to estimation soil erosion risk in Mubi South watershed with the aid of RUSEL model and Geospatial techniques. RUSLE model parameters such as rainfall, soil map, topography map, cover management and conservation practice factor map were derived. The method employed includes the use of RUSLE model and Geospatial techniques using ArcGIS 10.3 Software, for analysis and presentation of result. It was found that sandy soil are the dominant soil of the watershed which covered about 65%, 18% silt and 17% clay. The land use landcover has about 29% of area covered by agricultural activities, 19% were covered by forest and 25% were not cultivated and covered by bare land. The study area has about 0.58 to -0.07 normalized difference vegetation index (NDVI) with majority of the area within the lower topography of 570 m above sea level. The Soil cover management factor ranges from the higher value of 0.5 to the lower value of 0.01 in the watershed, 15.8 mm to 15.7 mm occurrences of daily rainfall and 492.34 mm rainfall and runoff covered when rainfall per-day is greater than 15 mm rainfall. The results of the study also show that average rate of soil detachment is 1 t ha-1 yr-1. The average transport capacity of overland flow is 1.5 t ha-1 yr-1. Average soil per detachability by raindrop is 69.6 t ha-1 yr-1 total soil particle detachments is 69.66 t ha-1 yr-1 and average estimated soil erosion of 3.52 t ha-1 yr-1. It is recommended that other soil erosion model to be applied in the study area for further comparative analysis of soil erosion risk.