Soil erosion effects and mechanisms in the karst peak-cluster depression area from a multi-scale landscape perspective

Abstract

The karst regions in southwest China are integral to maintaining regional ecological security. However, escalating human activities in these areas have intensified soil erosion and landscape fragmentation. Clarifying the role of landscape patterns in karst regions as drivers of soil erosion processes is essential for providing crucial support in mitigating regional soil erosion. By utilizing unmanned aerial vehicle detection, this study examined the soil erosion characteristics, driving factors, and interaction effects in peak-cluster depression landscapes. The investigation was conducted at multiple scales, including peak-cluster depression, grid, and patch levels, under the combined ecology–agriculture, ecology–economy and near–nature landscape utilization types. Furthermore, an optimal landscape pattern for alleviating soil erosion was identified. The research findings indicate that the proportions of mild and moderate erosion were higher in the ecology-agriculture landscape utilization type compared to the other two landscapes. In the ecology-economy type, slight soil erosion predominated. Increasing vegetation cover led to a decrease in soil erosion risk in the near-nature landscape utilization type. The interaction effects among factors contributed to an enhanced explanatory power for soil erosion. Particularly, the synergistic effect between vegetation coverage and land use exhibited the most significant influence on soil erosion. The mosaic distribution pattern of soil erosion sources and sinks, as well as the distribution pattern of fragmented source and aggregated sink distribution pattern, effectively mitigated soil loss, leading to reduced soil erosion rates.