GIS-based Evaluation Of Landslide Hazard In Fangshan District

Landslide is one of the most frequent and major geological disasters in the mountains of China.According to the results of the survey of 290 city and county geological disasters by the Ministry of land and resources,the landslide accounts for a high proportion of the total number of geological disasters,and the maximum can reach 51%(Xu Hui,2011).Like other geological disasters,landslides can cause injuries and major economic losses,and also break the ecological balance,cause the irreversible restoration of the environment,and the post disaster reconstruction work is tedious and costly.Therefore,it is necessary and urgent to study the landslide and the evaluation of its risk is one aspect of the research.The study of landslide hazard risk assessment provides scientific basis and decision support for effective government,and reduces the loss of life and property caused by landslides.In this paper,Fangshan is selected as the research area.Based on the geographic information system(GIS),the landslide hazard in Fangshan District is evaluated by means of analytic hierarchy process(AHP)and fuzzy comprehensive evaluation(FUZZY).The final results are obtained by comprehensive analysis and in-depth discussion,and the evaluation results are divided into high,middle and low risk areas.The main research contents and results are as follows:1.Based on the multi-source and multi temporal remote sensing data as the interpretation map,the landslide disaster points in Fangshan are interpreted with reference to the data of previous geological disasters.There are 101 geological hazards including 1,21 and 79 in the high,middle and small landslides.2.Collect and deal with the factors that affect the geological hazards of Fangshan landslide,analyze their influence on the landslide,and finally select them.In this paper,8 factors of rock and soil,fault,gradient,slope,vegetation coverage(NDVI),water system,road construction and mining activity are used as the index system for the risk assessment of Fangshan landslide.3.In this paper,the comprehensive analytic hierarchy process(AHP)and the fuzzy comprehensive evaluation method are used to evaluate the landslide hazard in Fangshan.It is concluded that the fuzzy comprehensive analysis method is more suitable for the evaluation of landslide hazard in Fangshan through comparing the mechanism,advantages and applicability of the two methods.4.Fangshan is classified into high,middle and low risk areas according to the risk level.The middle and high risk areas are mainly distributed in the central and northern parts of Fangshan,while the low risk areas are distributed in most parts of Fangshan.All factors have influence on the hazard zoning,but the influence of mining activity,fault activity and lithology is larger than other factors,especially the mining activity.The main threat to the landslide in Fangshan is the roads and mines nearby.