滑坡涌浪诱发冰湖溃决灾害链过程分析与模拟

近年来滑坡诱发冰湖溃决灾害链发生频率日趋增加，对下游居民及工程设施安全造成严重威胁。为定量描述滑坡诱发冰湖溃决灾害链危害，通过系统分析该灾害链的演化过程及阶段特征，将其划分为四个子阶段：滑坡运动、涌浪传播、冰湖溃决、洪水传播；分别研究各子阶段演化的物理机理及关键因子，建立了相应的数学模型与计算方法，如滑坡运动采用Savage-Hutter模型、涌浪及洪水传播采用浅水波方程等；通过确定各子阶段之间的衔接因子，如滑坡运动特征、涌浪传播特征、坝体溃决特征等，实现了各子阶段的过程耦合与数据传递，建立了滑坡-涌浪-冰湖溃决-洪水灾害链的全过程物理模型，最终完成了该灾害链的过程模拟与危险分析。为验证所建立模型与计算方法的可行性，以四川省甘孜藏族自治州雅拉乡木格措冰湖潜在灾害链为案例，结合现场勘查与卫星影像数据，开展不同情境如暴雨或上下游级联溃决等条件下灾害链的过程模拟与危险分析，且将模拟结果与经验公式计算数据进行对比。结果表明，本文所提方法可较好的完成滑坡诱发冰湖溃决灾害链过程模拟，模型模拟数据与经验公式计算数据较为吻合，且考虑暴雨或上下游级联溃决条件时下游洪水流量呈显著增加趋势。本文研究成果提供了一种新的滑坡诱发冰湖溃决灾害链研究思路，对该灾害链的防灾减灾技术具有重要支撑作用。

Dynamic Analysis and Numerical Simulation of Disaster Chain from Landslide,Surge Wave to Glacier Lake Outburst

Recently the disaster chain of landslide, surge and glacier lake outburst frequency increases, which poses a serious threat to the safeties of downstream residents and engineering facilities. In order to describe the hazards of this disaster chain quantitatively, its evolution process and corresponding characteristics are analyzed and further divided into four stages including landslide motion, surge 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 to achieve its 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, Yala village, Ganzi state, 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 and glacier lake outburst and the calculated data coincides 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 the prevention and mitigation of this type of disaster chain.