三峡库区沿江城镇地质灾害风险评价——以重庆市万州区大周镇为例

Risk assessment of geological hazards in towns alongside the Yangtze River in the Three Gorges Reservoir area:A case study of Dazhou Town in Wanzhou District of Chongqing City

针对三峡水利枢纽工程建成蓄水后,涉水新型城镇建设面临的地质灾害及其风险定量评价难问题,在地质灾害精细化调查基础上,以重庆市万州区大周镇集镇区为例,通过分析计算地质灾害的发育特征、稳定性和危害性,构建了基于斜坡单元的危险性评价和基于危险源分析的承灾体易损性评价的城镇尺度地质灾害风险评价框架。定量计算不同重现期降雨极值情景下的斜坡稳定性和不同灾害强度下承灾体易损性,实现了库区集镇区地质灾害风险评价;基于社会经济发展和地质灾害风险现状分析,提出了大周镇集镇区国土空间规划建议。地质灾害风险评价结果对制定地方发展规划具有指导意义,评价方法对同类沿江城镇地质灾害风险评价具有参考价值。

After the completion of the Three Gorges Water Conservancy Hub Project,the new type of wading town is confronting with the difficulties of geological hazards and risks quantification.Based on the fining geological investigation,the authors in this paper take Dazhou Town in Wanzhou of Chongqing as an example to analyze the development characteristics,stability and hazards of geological disasters and construct an urban-scale geological disaster risk assessment framework based on slope unit hazard assessment and disaster susceptibility assessment by hazard source analysis.The stability of the slope under the extreme rainfall scenario of different recurrence periods were quantitatively calculated,and the vulnerability of the disaster bearers under different disaster intensities were analyzed,which can help realize the geological disaster risk assessment in the market town area.Finally,the territory development suggestions of Dazhou market town were proposed based on development of social and economic and geological disaster analysis.The results of geological disaster risk assessment in this paper have guiding sig-nificance for local development planning,and references value for the geological disaster risk assessment of similar cities and towns along the river.