The impact of land cover changes on soil erosion hazard in a semi-arid sub-catchment

Land use and land cover change (LULCC) is a key global phenomenon with mixed consequences to earth systems. This study applied remote sensing and GIS modelling techniques to estimate soil loss and LULCC in Mutirikwi sub-catchment, Zimbabwe. In 1976, built-up area was 9.01% and increased to 27% by the year 2017. Agricultural fields increased from 1.50–11.32% from the period of 1976–2017. The CHIRPS 1 km2 spatial resolution rainfall data were spatio-temporally assessed for bias and used to analyse and estimate rainfall events related to rainfall erosivity. Results from monthly satellite rainfall performance validation were satisfactory with root mean square error (RMSE) = 5.08 mm and correlation coefficient = 1). The Revised Universal Soil Loss Equation (RUSLE) was used to estimate soil loss (1976–2017). Model simulation results indicate an average soil loss range of 0–531.05 tꞏha−1ꞏyr−1 in 1976, 0–373.70 tꞏha−1ꞏyr−1 in 1986, 0–200.82 tꞏha−1ꞏyr−1 in 1998, 0–106.16 tꞏha−1ꞏyr−1 in 2008 and 0–530.64 tꞏha−1ꞏyr−1 in 2017. Soil loss increased by 4.22% in 2017 for the 'high' class and increased by 2.88% for the 'very high' classes. About 7.10% of the study area lies within soil erosion hazard hotspots that indicate that water bodies within the sub-catchment are at risk from extreme rates of sedimentation. These results are important for catchment protection within the context of integrated water resources management.