Spatial analysis of soil erosion sensitivity using the Revised Universal Soil Loss Equation model in Nyamasheke District, Western Province of Rwanda

Abstract

AbstractPrevious studies have identified that Nyamasheke District in Rwanda is highly vulnerable to soil erosion. This has led to a loss of fertile soil, with a high level of land degradation. Nevertheless, the district’s spatial and temporal sensitivity to soil erosion remains unknown in different specific parts of the district. This study aimed to analyze spatial soil erosion sensitivity and mapping of vulnerable areas to soil erosion in the district. The Revised Universal Soil Loss Equation (RUSLE) model integrated within a GIS environment was used to estimate annual soil loss for the district. The RUSLE factors were derived from a 30 m resolution digital elevation model, digital soil map of the world, monthly rainfall records from 20 stations within and around the district, and Landsat7/ETM + and Landsat8/OLI imagery. Annual soil loss change was statistically analyzed using an empirical model in the district. The results showed a decreasing trend in soil erosion over time, with the highest annual soil losses estimated at 92.4, 16.1, and 15.1 t ha−1 year−1 in the years 2008, 2015, and 2018, respectively. Areas with the highest soil erosion sensitivity, with soil loss ranging between 10 and 40 t ha−1 year−1, were found in sectors of Kanjongo, Cyato, Rangiro, Macuba, and Karambi.