Modeling the Impact of Landscape Dynamics on Soil Erosion in Eastern DR Congo: Implications for Sustainable Land Management

Abstract

Human activity and related land-use/land cover (LULC) changes are the primary causes of accelerated soil erosion during the 21st century. However, there is limited information about the spatiotemporal dynamic of soil erosion under diferent conditions of LULC changes in mountainous regions of eastern DR Congo. In addition, the impact of landscape structure on soil erosion dynamics has not been assessed yet in this region despite that this information is crucial for sustainable land management. Terefore, the Kalehe territory which is subjected to an upsurge of hydroclimatic risks (erosion, landslides, and fash foods) was used as a case study. Te revised universal soil loss equation (RUSLE) modeling was integrated into the GIS environment to assess the synergy between the spatiotemporal changes of LULC and the dynamic of soil loss by erosion during the 1987–2020 period. Te historic LULC maps were obtained through the supervised classifcation of Landsat images. Te relationship between the annual soil loss and the landscape characteristics was assessed using the Pearson correlation, principal component analysis, and multiple linear regression model. Te results demonstrated that the soil erosion rate has increased over time from 32.08 t/ha/year in 1987 to 44.35 t/ha/year in 2020 due to the changes in landscape structure and composition. Te landscape metrics, which signifcantly infuenced the erosion dynamics with composition indices, collectively explained 60.9%, while the landscape structure metrics explained 34.89% of annual soil erosion rate variability in the best ft developed models. Te increase in soil erosion is positively infuenced by the deforestation, landscape diversity, and land fragmentation but negatively infuenced landscape complexity (irregularity of patch’s shape) and patch size. Tese fndings highlight the need for landscape-level management strategies to mitigate soil loss in Eastern DR Congo, emphasizing the importance of maintaining forest cover, preserving larger patches, reducing fragmentation, reducing the landscape diversity, and encouraging complex patch shapes.