基于GIS九龙县滑坡分布特征危险性评价

Risk Assessment of Landslide Distribution Characteristics in Jiulong County Based on GIS

川西地区地质环境特殊,是地质灾害最为发育的地区,其中以滑坡最为显著,给当地带来了极大的经济财产损失。选取甘孜州九龙县作为研究对象,该区所处的地质条件复杂常年以来滑坡极为发育,造成有众多的堵江堰塞。在野外工程地质调查及遥感解译的基础上对该区的历史滑坡进行了详细的分析,并选取有关影响因子建立评价危险性评价模型,使用层次分析法和熵权法组合模型在GIS平台上对该区的危险性进行区划,并生成危险性区划专题图,得出以下结论:九龙县的滑坡主要分布在河流水系支沟沟谷两岸,地形地貌因素是影响滑坡的主要因素,危险性评价区划显示:极高、高危险区占整个研究区面积的19.05%,中危险区19.11%,较低和低危险区占61.84%,通过ROC曲线验证评价结果,准确率高达86.4%,这对当地的防灾减灾工作和滑坡危险性评价方法具有重要的指导意义。

The geological environment in western Sichuan is special,and it is the most developed area of geological disasters.Among which the landslide is the most significant,which has brought great economic and property losses to the local area.In this paper,Jiulong County of Ganzi Prefecture is selected as the research object.The complex geological conditions in this area have developed extremely landslides over the years,resulting in numerous river blockages.Based on the field engineering geological survey and remote sensing interpretation,the paper analyzed the historical landslides in the area in detail,and selected relevant influencing factors to establish a risk evaluation model.Using a combination of analytic hierarchy process and entropy method to calculate in GIS,the risk of the area was divided on the platform,and a thematic map of the risk zoning was generated.The conclusion is as follows:the landslides in Jiulong County are mainly distributed on both sides of the river system branches and valleys,and topographical and geomorphological factors are the main factors affecting the landslide.Risk assessment zoning showed that the extremely high and high-risk areas accounted for 19.05%of the entire study area,the medium-risk areas accounted for 19.11%,and the medium-low and low-risk areas accounted for 61.84%.he evaluation results were verified by ROC curve,and the accuracy was as high as 86.4%,which has important guiding significance for local disaster prevention and mitigation work and landslide risk assessment methods.