Research progress and prospects of the giant Yigong long run-out landslide, Tibetan Plateau, China

Long run-out landslide is a landslide with high shear outlet, long sliding distance, large volume and high speed, which is characterized by strong kinetic energy, strong fragmentation-fluidization and entrainment effect.The landslide itself and its induced hazard chain are great harm to human life and property safety, road and bridge infrastructure and water conservancy and hydropower projects.Based on remote sensing interpretation and field investigation, this paper summarizes the research progress of the giant Yigong long run-out landslide in Xizang in 2000.It also delves into the initiation mechanism, landslide volume, movement speed, dammed lake volume and dam failure mechanism of Yigong landslide.Furthermore, it reveals that internal and external dynamic coupling is the main influencing factor of the Yigong landslide and considers that the landslide has periodic sliding mechanism of retrogressive erosion recurrence type.In additon, this paper calculates the landslide volume based on GIS and high-precision DEM and reveals that the landslide volume in the landslide source zone is about 9225×10⁴ m³.The landslide accumulation volume is about 2.81×10⁸~3.06×10⁸ m³, which is close to the domestic and international research.There are two potential instability rockmass in the landslide source zone of Yigong landslide, with a total volume of about 1.86×10⁸ m³.Once the two potential instability rockmass are unstable, the hazard chain of landslide-river blockage-dam break might be formed again and cause great harm.This study concludes by proposing research directions to further research the stability of the potential landslide of the Yigong landslide, predict the basin influence range of the hazard chain, establish the monitoring and early warning system.These suggestions have important guiding significance for the construction of major projects such as railway and hydropower projects being planned and constructed in this area, as well as for urban hazard prevention and mitigation.