基于多源信息融合的滑坡灾害链成灾机制及风险定量评价研究

It is increasingly clear that landslides represent a major cause of economic costs and deaths in mountainous area. Rainfall-induced cascading landslides continue to represent a major problem ten years on in the Wenchuan earthquake area, with little evidence of the rate of activity returning to background levels. In common with observed behaviour from elsewhere, landslides were not discrete events, but instead evolved over time in the form of a hazard chain including events such as rainfall-induced landslides, debris flows, landslide damming, dam-breach floods, severe sedimentation and changes in river course. Previous studies on rainfall-induced landslides tended to focus on separate landslide processes, with little attention paid to the quantification of multiple processes. Due to limited well documented fatality data, current risk assessment practices pay little attention to quantifying the increased risk associated with cascading landslides. Insufficient awareness of such risks has led to unexpected losses of lives and properties. Cascading landslides involve interactions among the hazards and among the vulnerabilities of the elements at risk to these hazards. Based on our 10 years investigation experiences on cascading landslides in the Wenchuan earthquake area, this project aims to explore failure mechanisms of rainfall-induced cascading landslides; to construct a numerical simulation method for the entire cascading landslide; and to develop a quantitative multi-hazard landslide risk assessment methodology. The outcome from this research project will improve the risk management of rainfall-induced landslides not only in China, but also in other landslide-prone mountain areas of the world.

强震后暴雨不仅导致滑坡大规模复活，更可诱发以“滑坡→泥石流→堵江”为代表的典型滑坡灾害链。主导灾害滑坡与泥石流间相互作用带来的放大效应会导致影响区内受灾体遭受更大的威胁。然而，构成滑坡灾害链的多种灾害的成灾机制是怎样？灾害链间及灾害与承灾体间的相互作用造成的风险放大及重叠效应如何量化？本课题将以典型滑坡泥石流灾害链为研究对象，基于多源信息融合技术，开展灾害链成灾机制及风险放大效应深入系统的科学研究；建立典型滑坡灾害链全过程模拟数值模型；创建滑坡灾害链风险定量评价体系。研究将立足于申请人在过去十年间对汶川震后降雨诱发滑坡及泥石流等地质灾害的深入现场调查、遥感解译、科学试验和理论分析所获取的大量一手资料，成果将应用于灾害频发的重点城镇如汶川震中区映秀镇，可为滑坡灾害链的预测、风险评估及应急管理提供强有力的科学依据。

强震后暴雨不仅导致滑坡大规模复活，更可诱发“滑坡→泥石流→堵江”为代表的的典型滑坡灾害链。主导灾害滑坡与泥石流间相互作用带来的放大效应会导致影响区内受灾体遭受更大的威胁。针对此，以申请人对地质灾害的深入现场调查、遥感解译、科学试验和理论分析所获取的大量一手资料为研究基础，基于多源信息融合技术，开展了滑坡灾害链成灾机制及风险放大效应深入系统的科学研究，建立了致死滑坡数据库，揭示了滑坡灾害链的时空分布规律、主要致灾情景等特性，揭示了滑坡灾害链间的相互耦合作用及放大重叠效应；建立了典型滑坡灾害链全过程数值分析平台；创建了滑坡灾害链风险定量评价方法。研究成果将在重点地区的滑坡灾害链风险预测中得以应用，可为滑坡灾害链的应急管理提供有力的科学依据。