Sensitivity analysis and calibration of the EUROSEM model for application in the northeast arid zone of Nigeria

Sensitivity analysis on the European Soil Erosion Model (EUROSEM) was conducted and it was found out that the parameters that affect infiltration of the soil are the most sensitive in the model as far as runoff volume is concerned. These parameters are maximum relative saturation of the soil. The model was calibrated using field data from the northeast arid zone of Nigeria. Calibration of the model was based on varying three parameters (maximum relative saturation, porosity and effective net capillary drive) within their range values until best fit between observed and simulated was achieved. Validation was achieved by comparing predicted runoff volumes with observed data not used in calibration. The model was evaluated using coefficients of efficiency and determination. Coefficients of efficiency of 0.82 and 0.74 in calibration and validation. The summary statistics confirmed that the EUROSEM model could adequately simulate surface runoff on the degraded lands of northeast Nigeria and therefore can be applied to runoff related research in the area.