基于GIS的凉山州德昌县滑坡危险性评价

滑坡会对人民生命财产和社会经济发展造成严重威胁。以滑坡发育密集的凉山州德昌县为研究区域,分析了该区滑坡的发育环境和分布特征,选取9类影响因素,运用信息量模型对德昌县滑坡地质灾害进行危险性评价,并以此为基础将研究区划分5个不同等级:极高度、高度、中度、轻度和极轻度危险区。结果表明:(1)滑坡危险性较大的区域主要分布在坡度8°～25°、高差50～100 m以及岩浆岩、变质岩和碎屑岩的区域,断层、水系、道路建设和人类活动均会很大程度的诱发滑坡,且随着降水量的增大滑坡发生的概率也增大;(2)滑坡主要沿河流两岸及外围密集发育,93.95%的滑坡集中在中度及中度以上危险区;极高和高危险区主要集中在安宁河流域、茨达河流域和雅砻江左岸的中高山峡谷地区,县域东部地区危险性较低,受滑坡灾害影响较小;(3)运用ROC曲线验证得到AUC值为0.843,评价结果较合理,可为德昌县的防灾减灾及后续规划工作提供基础的理论支撑。

Hazard Assessment of Landslide in Dechang County of Liangshan State Based on GIS

Abstract：Landslides will pose a great threat to people’s lives, property, as well as social and economic development.Taking Dechang County in Liangshan Prefecture with dense landslide hazards as an example, the essay analyzes the landslide development environment and distribution characteristics in the region.In this connection, 9 types of influencing factors are selected and information value model is employed to conduct hazard assessment of the landslide in the region.On this basis, the research area is divided into 5 levels from high to low: extremely high, high, moderate, mild and extremely mild.And conclusions are as follows: (1) Areas with high hazard of landslide are mainly distributed in places with slopes of 8° to 25°, elevations of 50 to 100 m, and places with magmatic, metamorphic and clastic rocks.Faults, river systems, road construction and human activities, to a large extent, will lead to landslides, the probability of which will increase along with the precipitation; (2) Landslides mainly occur by and around the river banks, and 93.95% of the landslides are distributed in regions of moderate and over-moderate areas; regions of extremely high and high are mainly concentrated in the Anning River Basin, the Zida River Basin and the middle and high mountain valleys on the left bank of the Yalong River.As for the east part of the county, the landslide hazards is less dangerous and less affected by; (3) The AUC value is 0.843 by using ROC curve, which indicates that the evaluation result is reliable.The research results will help to provide Dechang County with theoretical support for the disaster prevention and mitigation and subsequent planning work.