Research On The Assessment Methods Of Geological Hazard Susceptibility In Tonghua County,Jilin Province

Geological hazards are an important part of natural hazards.With population growth and accelerated urbanization,various engineering constructions and human activities are more important on the geological environment,and therefore geological hazards are becoming more and more frequent.Tonghua County is located in the northeast of China,and the potential geological hazards risk caused by the more complex geological environment poses a great threat to the life of local residents.In order to effectively prevent and mitigate the harm caused by geological hazards,it is important to conduct susceptibility zoning to target high susceptibility areas for management.This thesis is based on the"Geological Hazard Risk Survey Project in Tonghua County,Jilin Province"undertaken by the Natural Resources Bureau of Tonghua County.Through the collection of existing geological hazard results in Tonghua County,Jilin Province and relevant research data on geological hazards at home and abroad,different assessment methods are applied to carry out susceptibility assessment,and the reliability of susceptibility zoning under different methods is comprehensively compared.It can provide a reliable data base for the subsequent risk zoning and prevention zoning,and provide a reference for improving the geological hazard potential in Tonghua County,Jilin Province.In order to study the effect of susceptibility assessment under different assessment methods,this paper takes 99 collapse and landslide hidden geological hazards in Tonghua County as the research object,and selects suitable assessment factors to participate in the susceptibility assessment of collapse and landslide through quantitative calculation and theoretical analysis.Three models based on Information Value Model,Weights of Evidence Model and Logistic Regression Model were used for susceptibility assessment,and Natural breaks method was adopted for zoning,and the three results were compared and analyzed.The following conclusions were mainly obtained:（1）Field data from Tonghua County,Jilin Province,show that there are 90collapse hidden geological hazards and 9 landslide hidden geological hazards developed in the study area.Spatially,they are mainly distributed along rivers and roads in a belt pattern,and temporally,they are mainly concentrated in spring and the period of heavy rainfall.（2）By using ArcGIS software to grade and map the nine assessment factors of elevation,slope,slope direction,geomorphology type,geotechnical type,distance from river,distance from tectonic,distance from road and vegetation cover in Tonghua County,it can be found that the collapses and landslides are located at elevation of 400-500m,slope direction of 0-10°,southeast and south slope direction,erosion terrace,extremely soft rock,distance from river of 0-400m,distance from road of 0-500m,and distance from structures of 50-100m and 400-500m distance from structures,and 20%-60%vegetation cover,respectively.（3）The geological hazard susceptibility of Tonghua County was assessed using the Information Value Model,Weights of Evidence Model,and Logistic Regression Model through ArcGIS and SPSS software.Four zones were divided using the natural break method.According to the order of high,medium,low,and non-susceptibility,the areas of the Information Value Model were 496.72km²,772.33km²,1262.39km²,and 1168.38km²respectively.The areas of the Weights of Evidence Model were510.53km²,755.03km²,1228.88km²,and 1205.39km²respectively.The areas of the Logistic Regression Model were 554.32km²,629.67km²,966.36km²,and 1573.99km²respectively.（4）By comparing and analyzing the results based on the three assessment models,the logistic regression model has a larger R_eivalue in the high susceptibility area and a smaller R_eivalue in the medium susceptibility area,indicating that the model has a relatively higher possibility of falling in the high susceptibility area compared with the other two models,and therefore the evaluation zoning results are more reasonable.In summary,after selecting a more reasonable assessment method,the assessment results can lay a foundation for subsequent risk zoning,prevention and control zoning,and corresponding prevention and control work in the Tonghua County Research Area of Jilin Province,and also provide a reference basis for subsequent research areas with similar geological backgrounds.