Geological Hazard Risk Assessment In Yuanmou County Based On GIS

Yuanmou County is located in the north-central part of Yunnan Province,bordered by Panzhihua,Sichuan Province in the north.The vegetation coverage in the territory is relatively low,and mountainous and semi-mountainous areas occupy a relatively large area.There are more geological disasters in the area,which puts the lives and properties of local people at risk.The risk assessment of geological disasters not only considers the possibility of geological disasters,but also takes into account the extent of losses caused by geological disasters.The results of this evaluation can provide a certain theoretical basis for local development planning.This paper takes Yuanmou County as the research area,and obtains the geological conditions and the development characteristics of geological disasters in Yuanmou County through field surveys and data collection.This paper selects eight evaluation factors including slope,aspect,stratum lithology,geological structure,land use,rainfall,river network density,and road network density.Based on GIS,multiple methods are used to evaluate the susceptibility of geological hazards and then complete it.The risk assessment of geological disasters.The main research results and conclusions are as follows:(1)This paper uses five methods to evaluate the risk of geological hazards through analytic hierarchy process,fuzzy analytic hierarchy process,binary logistic regression analysis model,information volume method,and evidence credibility model.Then,the accuracy of the evaluation results was analyzed by the three methods of Kappa coefficient,ROC curve,and statistical analysis of the risk evaluation results,and it was found that the evaluation results made by the binary logistic regression analysis model had the highest accuracy,of which the area of high risk area was 421.61km~2;accounting for 20.74%,The area of the medium-risk zone is883.66km~2;accounted for 43.50%,the area of the low-risk zone is 620.80km~2;accounted for30.52%,and the area of the slight risk zone is 94.92km~2;accounted for 5.24%.(2)The fuzzy analytic hierarchy process is used to complete the vulnerability assessment of geological disasters.The vulnerability evaluation of geological disasters selected three evaluation factors:population,GDP,and road network density,and used two kinds of data to obtain two results.The results obtained by using the kilometer grid data of population and GDP are better than the results obtained by administrative statistics of population and GDP..Among them,the area of high vulnerability area is 83.29 km~2,accounting for 4.12%of the total area;the area of medium vulnerability area is 439.31 km~2,accounting for 21.73%of the total area;the area of low vulnerability area is 867.31 km~2,accounting for 42.90%of the total area;The area of slightly vulnerable area is 631.78km~2,accounting for 31.25%of the total area.(3)Using the geological hazard risk evaluation and vulnerability evaluation results obtained in the previous article,the geological hazard risk evaluation results of Yuanmou County are obtained,in which the area of high-risk area is 141.32km~2,accounting for 6.99%of the total area;the area of medium-risk area 588.72km~2,accounting for 29.12%of the total area;low-risk area1,291.46km~2,accounting for 63.88%of the total area.This result is more consistent with the result of the last geological disaster survey.Based on the results of the risk assessment of geological disasters,some prevention and control measures were provided for the governance of geological disasters in Yuanmou County.