Study On The Risk Assessment And Disaster Reduction Measures Of Geological Hazards In The Western Sichuan Mountain Area

As a mountainous and canyon area in southwestern China,the western Sichuan region is prone to frequent geological disasters,which pose a severe threat to social and economic development.Therefore,in order to minimize the losses caused by geological disasters in mountainous areas and improve the ability of regional disaster prevention and reduction work,it is urgent to carry out geological disaster risk assessment and disaster prevention countermeasures research,providing theoretical basis and guidance for regional geological disaster prevention and control work.This article takes Jiulong County as the research area and studies the spatiotemporal distribution characteristics of geological disasters through the analysis of historical disaster data.Based on the selection principles of evaluation factors,evaluation factors are selected to establish an evaluation index system for the risk level of geological disasters in Jiulong County.With the help of Geographic Information System(GIS)technology,the risk analysis and evaluation of geological disasters in Jiulong County are conducted,and the information quantity model is compared and analyzed Logical regression model and random forest model are used to verify that the logical regression model is more suitable for the risk assessment of geological disasters in high and steep mountain areas.Finally,based on the risk assessment results of geological disasters in Jiulong County,a preliminary disaster prevention and reduction strategy was proposed,and the main achievements were as follows:(1)The study revealed the types and distribution patterns of geological disasters in Jiulong County.The investigation and analysis showed that the number of geological disasters in Jiulong County is mainly composed of debris flows,with 251 occurrences developed;Landslides followed,with 185 developed areas;Collapse and unstable slopes are the least developed,with a total of 63 locations.Mainly distributed in towns such as Naiqu Town,Xuewa Long Town,and Yanbao Town,it is distributed along the G248 highway and the Yalong River,and is generally distributed in a strip or sheet shape,with a spatial distribution characteristic of more in the south and less in the north.(2)A systematic evaluation index system for geological hazard risk in Jiulong County has been constructed.Based on GIS data analysis and spatial management functions,the relationship between the distribution characteristics of geological disasters and factors such as terrain,regional geology,meteorology,hydrology,and human engineering activities in Kowloon County was quantitatively analyzed,revealing the distribution relationship between geological disasters in Kowloon County and elevation,slope,annual precipitation,etc.Based on the principles of selecting disaster causing factors and correlation analysis,12 indicator factors,including elevation,annual precipitation,and vegetation index,were determined to construct an evaluation index system.(3)We conducted a geological hazard risk assessment and accuracy testing in Jiulong County.Through the analysis of hidden danger points and evaluation factors of geological disasters,three methods of Information Value model,Logical Regression model and Random Forest model are used to evaluate the risk of geological disasters,and Jiulong County is divided into five grades according to the degree of risk.Among them,high risk areas account for 5.19%of the area of Jiulong County,and low risk areas account for 32.31% of the area of Jiulong County.Using the ROC curve,the AUC values of the three models were all greater than 0.8,verifying the feasibility of the three models.The AUC values of the three models were 0.901,0.914,and 0.875,respectively.The Logistic Regression model has the highest AUC value,and the best method for evaluating the risk of geological disasters in Jiulong County is the logistic regression method.According to the test results,it can be seen that this method has a certain degree of popularity and is a beneficial exploration for the risk assessment of geological disasters in mountainous areas.(4)Proposed disaster prevention and reduction measures and suggestions for Jiulong County.Based on the principles of disaster prevention and reduction at home and abroad,and in response to the characteristics of geological disasters in Jiulong County,measures such as innovating prevention and control concepts,updating prevention and control ideas,optimizing governance mechanisms,increasing the utilization of new technologies,and planning emergency shelters have been proposed.Preliminary suggestions for disaster prevention and reduction measures have been proposed.