| Geography Information System is a tools based computer, It can analyze anddispose the spatial information, have a strong ability to space comprehensiveanalysis and dynamic prediction, and produce a high level of geographic information.At present, GIS technology has extensive application fields at home and abroad. Thispaper tries to use GIS technology to research on geological disaster susceptibilityevaluation in Lang county area, in order to efficiently and accurately find out thedistribution and lability zoning of geological hazards in research area.Focusing on the geological disasters susceptibility assessment, and taking LangCounty in Tibet autonomous region as the research object, this paper analyzestemporal distribution characteristics of each kind of master disaster, and makescorrelation analysis to important factors for geological disasters, then get therelationship between the main geological disasters and the influencing factors inresearch area. According to the actual geographical environment in research area,this paper chooses effective evaluation factors to build a geological hazard riskevaluation index system, then uses the relevant evaluation model based on GIS—Fuzzy comprehensive evaluation model based on AHP and Fuzzy comprehensiveevaluation model based on information entropy to study the geological disasterssusceptibility assessment in research area, gets the geological disaster prone zoningmap of research area, then makes the geological disasters prone zoning about thestudy area. Finally, put forward the prevention suggestions based on the above studyresults.The main research contents are as follows:(1) According to the study on geological environment condition, and analyze byfield survey of the study area and the related materials of indoor, this papersummarizes the development rules, scale features and influencing factors ofgeological disasters in the study area, then knows the major geological disasters as collapse, landslide, and followed by debris flow in the research area. In addition, thegeological disasters of study area have the seasonal distribution characteristicsgenerally, especially during the flood season, it is the period of multiple to geologicaldisasters in the study area.(2) This paper chooses the grid unit as evaluation unit, Selects the six factorsinduced slope, and aspect, and formation lithology, and distance of tectonic effects,and the monthly mean rainfall and the development point density density asevaluation factors. Based on the principle that construction of evaluation system, thispaper chooses some factors that are more important to geological hazard as theevaluation factors, then builds a geological hazard susceptibility evaluation indexsystem.(3) By using fuzzy comprehensive evaluation model based on AHP and fuzzycomprehensive evaluation of information entropy model based on geologicaldisasters, it make a quantitative evaluation of susceptibility in the study area. At first,calculate the weight of each evaluation factor by using the Analytic HierarchyProcess and Information Entropy method, then through using Fuzzy comprehensiveevaluation method, it determines the evaluation model, and calculate everyevaluation factor membership degree to structure the fuzzy evaluation matrix, andthen And then the fuzzy comprehensive evaluation of the study zone will be carriedout. Then the study area is prone to is divided into three grades, that is low proneareas and in the prone areas and high prone areas. Finally, get the geological disasterprone zoning map on the study area.(4) Based on the actual situation of geological disasters in the study area andcomparing the geological hazard susceptibility results, this paper analyzes thereasons for the differences for obtaining one more reasonable, more effective, moreaccurate evaluation results, and then partition the zone according to the evaluationresults.(5) Based on the actual situation of geological disasters in the study area, basedon the above research results, this article puts forward some necessary controlmeasures and prevention suggestion for the prevention of geological disasters. |
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