Classification and Remote Sensing Characterization of Large Catastrophic Landslides in the Southeastern Tibetan Plateau, China

Large catastrophic landslides in the southeastern Tibetan Plateau are characterized by huge volumes and complex chains that frequently cause river damming and casualties. Based on field surveys, multi-temporal satellite imagery, Unmanned Aerial Vehicle (UAV), Interferometric Synthetic Aperture Radar (InSAR) deformation measurements, and meteorological and seismic records, this study classifies these landslides into three types by their initiation and disaster-chain processes: (1) rock–ice avalanche → debris flow → landslide dam; (2) debris flow → landslide dam; (3) rock avalanche → landslide dam. Representative cases illustrate the material sources, initiation settings, and downstream impacts of each type. The occurrence of such landslides is influenced by the interplay of four groups of factors: fractured rock masses and abundant loose deposits provide the material basis; high mountains and narrow river valleys provide the spatial framework for landslide evolution and promote river blockage; pronounced climatic changes provide the background conditions and may affect slope stability in glaciated areas through glacier retreat; and frequent strong earthquakes can both instantaneously trigger failure and cause cumulative damage that predisposes slopes to subsequent failures. Ongoing climate warming and repeated seismic activity are expected to increase landslide susceptibility, highlighting the urgency of multi-hazard early warning and proactive mitigation. This study supports early warning prioritization and risk governance in high-mountain valleys across the Tibetan Plateau.