Abstract:Recently the frequency of disaster chain of landslide, surge wave and glacier lake outburst increases, which poses a serious threat to the safety of downstream residents and engineering facilities. In order to describe quantitatively the hazards of this disaster chain, its evolution process and corresponding characteristics are analyzed and further divided into four stages including landslide motion, surge wave propagation, glacier lake outburst and flood propagation. The physical mechanisms and key factors of these stages are investigated and based on this the corresponding model and numerical scheme are also established. For example, the Savage-Hutter model and shallow water model are applied to describe landslide motion and surge/flood propagation, respectively. By determining the factors that connect each stage, the coupling and data transmission of these stages are achieved and therefore a comprehensive model of this disaster chain is presented for process simulation and hazard analysis. In order to verify the feasibility of the presented model and numeric scheme, a potential disaster chain in Mugecuo glacier lake near Yala village, Ganzi state of Sichuan province is studied. Based on the data of field investigation and satellite imagery, the process of disaster chain under several scenarios such as heavy rainfall and cascade dam break are performed and the simulated results are compared with that of empirical formula. These results show that the presented method is quite effective to simulate the disaster chain of landslide, surge wave and glacier lake outburst and the calculated data agree with that of empirical formula. It also indicates that the flood discharge can be increased significantly due to the effects of heavy rainfall or cascade dam break. This research provides a new idea for studying the disaster chain of landslide, surge and glacier lake outburst and has some consultative value to prevent and mitigate this type of disaster chain.