Research On Geological Hazard Space Division And Application Of Railway Line Planning And Design In Ganzi-changdu Region Based On GIS

With the gradual implementation of “the Belt and Road Initiative”and “Thirteenth Five-year Plan for Railway Development”,the development of railway foundation facilities in the western region will go to meet new opportunity of development.Sichuan-Tibet Railway and Yunnan-Tibet Railway have been planned only in the southwest region,which are main railway passage to Tibet.The Kangding-Changdu section of the Sichuan-Tibet railway needs to cross the high mountain areas of western Sichuan and the high mountainous areas of the Hengduan Mountains in the southeast of Tibet.The survey,design,construction and operation of the Sichuan-Tibet railway will face unprecedented challenges.The geological disasters in the Ganzi-Changdu area are abnormal development.There is a high potential risk due to lack of detailed geological data and difficult to identify accurately in the early planning stage of the railway project.The use of existing environmental spatial data to quantify and assess the susceptibility of geological disasters has great significance to the planning and design of railway lines.Therefore,this paper takes the Ganzi-Changdu region as the research object,studies the susceptibility of geological disasters in this region,discusses the quantitative representation of the susceptibility of geological disasters,draws geological disaster susceptibility zoning maps in the Ganzi-Changdu region,and explores its application in railway line planning and design of the Kangding-Changdu section of the Sichuan-Tibet Railway.First of all,this paper obtains data on terrain,geology,hydrology,and human activities in the Ganzi-Changdu region through information collection and organization on natural geography,geological environment,current status of disasters,and population economics in the Ganzi-Changdu region.By the use of Geographic Information System(GIS)technology,this paper sets up environmental spatial database in the Ganzi-Changdu region.Then,this paper extracts the influence factors of landslides,collapses,and debris flows in the Ganzi-Changdu region and normalizes the factors according to certain accuracy.On this basis,this paper analyzes the distribution characteristics of the existing geological disasters under each factor category.Through the analysis of the correlation of impact factors,the indicators of geohazard emergence evaluation are selected.The subjective and objective weights of the indicators are determined by the use of analytic hierarchy process and entropy method.Secondly,this paper calculates the susceptibility of major geological hazards in each evaluation unit by the improved weighted information method and support vector machine method,and uses ROC curve and space entropy to verify the validity of the two methods of geological disaster susceptibility evaluation results.This paper integrates the three major geological hazards and draws a comprehensive map of geological hazards in the Ganzi-Changdu region.Finally,this paper explores the application of geohazard susceptibility information map in the four aspects of railway station site selection,line program generation,line program selection and emergency resource optimization based on the quantified results of geological disaster susceptibility.