Unraveling shallow landslides in the Qinling Mountains: Novel insights into vegetation-hydrology driven mechanisms

As a critical ecological barrier in China, the Qinling Mountains see their ecological functions significantly impaired by frequent shallow landslides. However, existing research on the distribution characteristics and driving mechanisms of such landslides remains relatively limited. To address this knowledge gap, the present study integrated data analysis, field investigations, and remote sensing interpretation to construct a landslide database for the core area of the Qinling Mountains, and systematically analyzed the spatial patterns, development characteristics, and environmental driving factors of shallow landslides. The results reveal that shallow landslides are predominantly small-to-medium in scale, concentrated in regions with an altitude of 800–1000 m and a slope gradient of approximately 30°, with a distinct tendency to develop on sunny (south-facing) slopes. The occurrence frequency of these landslides exhibits a significant positive correlation with the soil moisture content of the weathered layer and the degree of groundwater enrichment in the study area. Specifically, these landslides are mainly developed in bedrock fissure water zones and karst fissure water zones with favorable water-bearing capacity, indicating that rainfall and surface hydrological processes are the key triggering factors for shallow landslides. Notably, vegetation exerts a mediating role in the "vegetation-hydrology-landslide" system: shallow landslides occur most frequently in areas with artificial or shrub-grass vegetation, peaking at a moderate coverage of 50%–60%. This peak suggests that vegetation within this range is ineffective at regulating soil moisture, while the interaction between specific vegetation types and hydrological enrichment further exacerbates landslide risk. By prioritizing the weights of vegetation and hydrological factors, we enhanced the information quantity model, which significantly improved its performance and increased the AUC value to 0.83. These findings confirm the pivotal roles of vegetation and hydrological factors, thereby providing a robust scientific basis for targeted landslide prevention and control in this region.