南方山地丘陵区典型地质灾害成因机制与风险评价

南方山地丘陵区地域跨度大,地质灾害孕灾背景复杂、成灾模式多样,是我国地质灾害高易发区。针对南方山地丘陵区地质灾害潜在风险高的问题,在中国地质调查局“南方山地丘陵区地质灾害调查工程”实施进展基础上,对南方山地丘陵区地质灾害控灾的气候动力特征及地质构造背景进行了系统分析,对典型地质灾害成灾模式和多尺度风险调查评价示范性成果进行了总结,揭示了东南沿海地区典型台风地质灾害、南方岩溶塌陷、西南高寒山区冰碛土泥石流及川西高原区火后泥石流形成机理与物源侵蚀机制。在此基础上,开展了南方山地丘陵区基于县域、重点城镇及典型灾害点的多尺度地质灾害风险评价应用示范,相关成果在西南重大工程规划选线及县城搬迁选址中得到应用。

Genetic mechanism and risk assessment of typical geological hazards in mountainous and hilly areas of South China

The mountainous and hilly area of South China has a large geographical span, with complex geological hazard pregnant background and diverse disaster modes, and it is an area with dense distribution of geological hazards in China. Aiming at the potential risk of geological hazards in mountainous and hilly areas of South China, the authors in this paper systematically analyze the climatic dynamic characteristics and geological structure background of geological hazard in mountainous and hilly areas of South China, based on progress of the implementation of “geological hazard investigation project in mountainous and hilly areas of South China” by China Geological Survey. The disaster models of typical geological hazards and the demonstration results of multi-scale risk inve-stigation and evaluation are analyzed, and the formation mechanism and provenance erosion mechanism of typical typhoon geological hazards in southeast coastal areas, karst collapse in South China, moraine soil debris flow in southwest Alpine mountainous areas and post fire debris flow in Western Sichuan Plateau are revealed. On this basis, a multi-scale geological hazard risk assessment demonstration based on counties, key towns and typical disaster points in mountainous and hilly areas of South China was carried out, and the relevant results were applied in the planning and route selection of major projects in Southwestern China and the relocation site selection of counties.