青藏高原东缘大型滑坡-堰塞湖-溃决洪水灾害链动力演进物理模型与定量预测

In recent years, the worldwide global warming, glacial retreat, frequent extreme weather, active seismic activity, and human engineering activities strengthening are occurring, which results in an exacerbated risk of large-scale landslides and derivation disaster chain in the eastern Tibet plateau, leading to a serious threat to people's life and property and major engineering security. Thus, a research which takes "large-scale landslide - landslide dam - lake outburst flood disaster chain" as the object is conducted, with the view of revealing the relationship between rapid migration process of material and energy transforming as well as the morphology change and critical transform conditions in disaster chain evolution process under the condition of high gradient environmental; building the large-scale landslide dynamic evolution physical model, the landslide intruding and further blocking river and surge propagation physical model, as well as the overflowing landslide dam and dam-break flood propagation physical model according to the characteristics of three evolution stages in the disaster chain; developing an efficient adaptive algorithm; building a numerical simulation platform for disaster chain dynamic evolution with independent intellectual property rights; realizing the simulation of whole process of disaster chain dynamic evolution and quantitative forecast the space-time evolution of disaster; providing the theoretical foundation for the risk analysis and regulation of large-scale landslide - landslide dam - lake outburst flood disaster chain.

近年来，全球变暖、冰川退缩、极端天气频现、地震活跃，人类工程活动加剧，青藏高原东缘大型滑坡及其衍生灾害链的风险日益升高，给人民生命财产和重大工程安全构成严重威胁。为此，以“青藏高原东缘大型滑坡-堰塞湖-溃决洪水灾害链”为研究对象，揭示高位能大梯度环境条件下物质快速运移过程与能量转化关系，灾害链动力演进过程中的性态改变与临界转化条件，根据灾害链三个演化阶段的特点，构建大型滑坡动力演进物理模型、滑坡入水堵江成坝与涌浪传播物理模型、堰塞坝漫顶溃决与溃坝洪水演进物理模型，发展高效自适应算法，搭建具有自主知识产权的灾害链动力演进数值仿真平台，实现滑坡-堰塞湖-溃决洪水灾害链动力演进全过程模拟与灾情时空演化定量预测，为大型滑坡-堰塞湖—溃决洪水灾害链定量风险分析与调控提供理论基础。

受地震、全球气候变化等内外动力作用综合影响，青藏高原东缘滑坡-堰塞湖-溃决洪水灾害链异常活跃。特别项目执行期间，2018年金沙江上游白格滑坡造成了近百年来最为严重的干流堵江事件，堰塞湖的形成和溃决给下游金沙江沿线造成重大经济和财产损失。因此，揭示重大滑坡-堰塞湖-溃决洪水灾害链动力学机理，实现链式灾害成灾全过程模拟与灾情时空演化定量预测对减灾防灾具有特别重要科学意义和工程实际意义。.一、主要研究内容.（1）青藏高原东缘高位能大梯度条件下滑坡动力演进物理机制与过程模拟.（2）滑坡入水堵江物理机理与堰塞坝形成过程模拟.（3）堰塞坝漫顶溃决侵蚀机制与溃坝洪水演进预测.（4）大型滑坡—堰塞湖-溃坝洪水灾害链动力演进定量预测.二、重要结果.1、滑坡-堰塞湖-溃决洪水灾害链动力学机理与物理模型构建.揭示了滑坡-堰塞湖-溃决洪水灾害链链生转化机制，建立了滑坡堵江临界阈值条件；基于灾害链演进三阶段特点，构建了考虑摩擦弱化与沿程侵蚀的滑坡动力学物理模型、滑坡入水堵江与涌浪传播的双层流模型、考虑下切与侧蚀耦合的堰塞坝溃口演化与溃决洪水演进模型。.2、滑坡-堰塞湖-溃决洪水灾害链成灾全过程数值模拟平台.基于滑坡-堰塞湖-溃决洪水灾害链动力物理模型，结合灾害链时空演化过程与数据链传递关系，构建了滑坡-堰塞湖-溃决洪水灾害链数值模拟平台，首次实现了灾害链运动演进-成灾全过程数值模拟与危险性定量预测。 .3、潜在滑坡-堰塞湖-溃决洪水灾害链定量风险评估.基于项目研发的滑坡-堰塞湖-溃决洪水灾害链数值模拟平台，开展了2018年白格滑坡-堰塞湖-溃决洪水灾害链成灾过程模拟；金沙江沃达滑坡堵江风险预测以及川藏铁路康定车站木格措冰湖溃决风险定量预测研究。.三、科学意义.川藏铁路、雅下水电站等重大工程都面临链式灾害的重大威胁，本项目研发的灾害链数值模拟平台可为潜在链式灾害危险性预测与定量风险评估提供关键平台支撑，对青藏高原链式灾害减灾防灾将发挥积极作用。