A large landslide on the upper reach of the Jinsha River, SE Tibetan Plateau: characteristics, influencing factors, and mechanism

On October 11 and November 3, 2018, two large landslides occurred at the same location in Baige Village, eastern Tibet, China. These landslides pose a serious threat to both upstream and downstream areas, raising great concerns in China and worldwide. Currently, the influencing factors and fundamental mechanism of the Baige landslide are questioned, and further research is needed. Multiple methods, including comprehensive field investigation, satellite remote sensing, unmanned aerial vehicle (UAV) 3D imaging, and geographical information systems, are used to analyze the main characteristics, influencing factors, and fundamental mechanism of the Baige landslide. The results reveal that the occurrence of the Baige landslide is closely related to deep-seated gravitational slope deformations (DSGSDs); tectonic activity, river incision, earthquakes, and rainfall are also responsible for the formation of the event. From a long-term perspective, DSGSDs, active tectonic deformation, repetitive seismic activities, rapid river incision, and sustained rainfall infiltration all interact with each other and finally trigger catastrophic landslides. The damage deformation process of the Baige landslide can be divided into three stages: epigenetic deformation, time-dependent deformation, and failure. Some unstable rock masses still exist in the source area, and thus, successive deformation monitoring and timely mitigation measures should be implemented to reduce the residual risks. The research in this paper is meaningful for further research on such large-scale landslides along the Jinsha River.