区域滑坡灾害风险评估——以长江三峡库区秭归县为例

Risk Assessment of a Regional Landslide: A Case of Zigui County Territory in Three Gorges Reservoir

以滑坡灾害突出的三峡库区秭归县为研究区。在深入分析滑坡孕灾环境、诱发因素、滑坡编录和承灾体信息的基础上,利用Logistic回归模型和统计分析方法相结合进行了滑坡危险性评价。通过滑坡灾害致灾强度与承灾体抗灾能力分析了人口、建筑物、生命线工程和土地资源的易损性。采用成本价值核算法对各类承灾体进行了价值核算,最后通过风险模型预测了研究区内未来10年滑坡灾害的生命与经济风险。生命和经济高风险区分别占整个研究区面积的1.11%和2.71%,主要分布在集镇和学校、企事业单位等人口密集区以及交通建设用地等经济价值大的地区;中风险区分别占13.21%和20.66%,主要分布于农村居民生活居住和耕地活动区;低风险区分别占85.68%和76.63%,则分布在经过地质灾害治理和人类活动较为稀少的未利用地及林地等区域。通过实地调查分析与对比验证,发现预测结果与实际灾情较吻合。研究表明,集镇和学校、企事业单位等人口集中区和交通建设用地区是今后减灾防灾部署工作的重中之重。

Zigui County with prominent landslide hazard in Three Gorges Reservoir was taken as study area to conduct systematic research on landslide risk assessment.Based on the detailed analysis on landslide environmental factors,triggering factors,landslide inventory and the information of disaster bearing elements,landslide hazard was quantitatively assessed by using logistic regression model combined with statistical analysis method.The vulnerability of the population,buildings,lifeline engineering and land resources were calculated according to the landslide hazard intensity and the resistance ability of disaster bearing elements.Values attributed to disaster bearing elements were obtained by cost-value method for each element.Finally,landslide risk analysis considering life and economic costs were carried out through quantitative risk models in the studied area for next ten years.Highly risk areas of life and economic account for 1.11% and 2.71% respectively of the total studied area,and mainly distributed in the market town,school and enterprise residential quarters,transportation and construction land where there were dense population and prosperous economic value.Areas with moderate risk account for 13.21% and 20.66% separately,which were primary distributed in the rural residents and cultivated land.Low risk areas account for 85.68% and 76.63% individually mainly distributed in the area of treated geological hazard zone and little human activity of unutilized land and forest land.Combining with the field survey data,the risk analysis results were basically consistent with the status of local landslide disasters.It can be concluded that the critical areas,such as town,schools,enterprises,transport lines and so on,where damages are likely to be great require priority for mitigation actions.