Abstract:On October 11 and November 3, 2018, at the junction of Baige Village, Boluo Township, Jiangda County, Tibet, and Zeba Village, Ronggai Township, Baiyu County, Sichuan Province, two landslides occurred on the right bank of the Jinsha River, blocking the Jinsha River and forming a barrier lake. The first landslide blocked the Jinsha River and released its natural flow on October 12. The danger was relieved on October 13; The second landslide blocked the Jinsha River again. Under the guidance of relevant departments, the manual excavation of diversion channel was adopted to start the flood discharge on November 12, and the danger was relieved on November 13.Based on the Voellmy rheological model, MassMov2D is used to simulate the movement and accumulation of two landslides in the environment of PCRaster. The inversion results of the second landslide are used to predict and analyze three potentially unstable rock masses in the source area of Baige landslide. The simulation results show that: MassMov2D can be used to simulate the landslide-debris avalanche of Baige landslide in Jinsha River. The main accumulation areas and thickness of the two landslides are close to the actual situation. The inversion parameters of the second landslide simulation are used to predict three potentially unstable rock mass bodies. It is assumed that three unstable rock and soil bodies will slide simultaneously and form a 64 m high barrier dam, which may block up the Jinsha River again and form a barrier lake.