Evaluating the Impacts of Soil Erosion on Selected Hillslopes in UNN Using WEPP Model

Abstract

Soil erosion is a major form of degradation experienced by Nsukka agricultural lands. Literatures have proven the problem to be one of the major reasons for reduced agricultural yield and other forms of land use. However, the use of hydrological models has aided the problem-solving approach towards its remediation. The Water Erosion Prediction Project (WEPP), a physically based hydrological model, was used in this study to estimate runoff and soil loss through predictive mechanisms across different scales of space and time. A number of hillslopes were considered, and different rainfall events were also monitored within the University of Nigeria, Nsukka (UNN) environment Data on soil, topography, land use, and rainfall events were entered into the model and the predicted runoff and soil loss values were compared to the measured values. However, observations from the WEPP model predicted a maximum soil loss of 0.038 kg/m² at 1111.460 m and 1145.140m along the hillslope profile and a minimum soil loss of -0.199 kg/m² at 3368.060 m along the hillslope profile. Therefore, it can be concluded that the amount of soil loss varies with the steepness or land configuration. These findings are particularly useful for farmers and engineers in improving farm management techniques, informing better soil and water conservation methods and site preparation, planning and design respectively.