Assessment Of Landslide Hazard Susceptibility Based On Information Method In Lanzhou City

Lanzhou city is located in the Yellow River valley area,which is the junction of Qinghai-Tibet Plateau and the Loess Plateau.The geological conditions are complex.Restricted by the two mountain terrain,the land resources are short.The human engineering activities are strong here,so that landslide disaster occurred frequently.It has become one of the main factors that restrict the region's economic and social development presently.Studies of landslide susceptibility evaluation in Lanzhou city is necessary,which is the foundation of hazard evaluation and risk assessment.The landslide susceptibility evaluation result can be used to establish the regional land use planning as well as provide data base for the meteorological geological disaster early warning forecast.Based on the existing landslide spatial database,this article carries out landslide control single factor sensitivity analysis.Then optimizing the susceptibility evaluation model constantly,a set of susceptibility evaluation model system and process in accordance with the regional geological environmental characteristics is set up,which can provide reference for the future similar research using GIS technology.According to the geological environmental conditions of the study area,the development type of landslide hazards in Lanzhou city are roughly introduced,and analyzes the main influence factors of landslide development.Finally,topographic slope,terrain slope aspect,terrain curvature,land relief,landuse types and distance from roads are selected as 6 evaluation indexes of the study area.Information method is used to determine the weight of each evaluation index,then to do linear normalization processing with them.Using spatial analysis function of ArcGIS to compile the weight layer of each influence factor,then using the calculated weights between layers to grid compute.Classify the result by using the natural discontinuities classification method.Finally gets Lanzhou landslide disaster susceptibility partition layer in 2016.Using the same method to map the landslide susceptibility partition layers of 2000 and 2012 based on existing data,test the classification results of three years by the ROC curve and compare them with each other.Finally based on the landslide susceptibility partition layer in 2016 which the most conforms to the actual situation,the study area is divided into the high susceptibility areas,the middle susceptibility areas,the low susceptibility areas and stable areas.The high susceptibility areas are mainly distributed in the south,northwest steep mountains and irrigated woodland of the study area.This article carries out landslide disaster susceptibility evaluation in lanzhou city by using the method of information methods,at the same time,breaks the traditional susceptibility evaluation in people's minds.It takes the change of evaluation index and the human engineering activity factors which cannot be ignored into consideration in the strong and frequent human engineering activities area,for breaking the bottleneck of geological hazards susceptibility assessment in the areas where conditions of geological environment are badly affected by human engineering activities,and providing the people a new perspective of understanding susceptibility evaluation.