Abstract:
Landslides occur frequently in the alpine-gorge region of southeastern Xizang, where abrupt land-cover changes at the patch scale can rapidly alter hillslope hydrology, soil retention, and carbon storage processes. To identify the immediate ecosystem service losses after landslide disturbance, this study selected 389 landslide patches in Cuona City, Longzi County, Milin City, Medog County, and Bayi District as the study objects. Based on pre-landslide original land-cover and post-landslide bare-land disturbance scenarios, the InVEST model was used to quantify changes in water yield, soil retention, and carbon storage. Topographic factors, remote-sensing indices, and SHAP, an interpretable machine learning method, were further integrated to identify the dominant controlling factors. The results showed that after landslide disturbance, mean water yield increased by 60.1%, whereas evapotranspiration intensity decreased by 63.0%, indicating that more water was converted into rapid hillslope runoff rather than contributing to enhanced hydrological regulation. Soil retention and carbon storage decreased by 77.0% and 87.4%, respectively, and the area-specific erosion intensity increased to 33.4 times the pre-landslide level. A total of 63 patches with high composite disturbance were identified by the comprehensive disturbance index, mainly concentrated in Medog County and Cona City. Topographic factors were the primary controls on the spatial differences in ecosystem service losses. Changes in water yield were mainly controlled by elevation relief amplitude and slope relief amplitude, with contribution rates of 39.03% and 32.54%, respectively. Soil retention loss was mainly controlled by mean elevation and elevation relief amplitude, with contribution rates of 37.94% and 36.07%, respectively. Carbon storage loss was primarily controlled by elevation relief amplitude, with a contribution rate of 36.86%. Remote-sensing indices mainly reflected post-landslide vegetation removal, bare-land exposure, and surface moisture loss. These findings provide a scientific basis for prioritizing post-landslide ecological restoration and implementing zonal hillslope management in southeastern Xizang.