Research On Geological Disaster Risk Assessment In Liuhe County Jilin Province

Liuhe County is located in Tonghua City,Jilin Province,in the western part of Changbai Mountain District.The main geomorphic type is medium to low mountains,with large cutting depths,steep slopes,poor geological environment quality,and strong human engineering activities.Under the influence of rainfall or external conditions,four types of geological disasters,namely collapse,landslide,debris flow,and ground collapse,have been caused in the area,causing serious economic and property losses to the local area.Therefore,conducting geological disaster risk assessment in Liuhe County provides a basis for relevant departments to develop emergency plans and prevention measures for geological disaster management,while also ensuring the safety of the lives and property of the people in Liuhe County,which has important practical significance.This paper takes Liuhe County as the research object.Through data collection,remote sensing interpretation and field ground investigation,the development characteristics and distribution laws of geological disasters in the study area of Liuhe County are identified.random forest and support vector machine models are used to evaluate the risk of geological disasters in Liuhe County,and analytic hierarchy process is used to evaluate the vulnerability of geological disasters in Liuhe County.Finally,the risk assessment results of geological disasters in Liuhe County are obtained.The following conclusions are drawn from this study:1)After field investigation and data collection,it was found through analysis that the occurrence and development of geological disasters in Liuhe County are related to geological conditions such as ground slope,ground elevation,geomorphic morphology,engineering geological rock formations,slope structure,groundwater,rainfall intensity,vegetation coverage,and human engineering activities.There are currently 93 geological disaster points in Liuhe County,including 83 collapses,7mudslides,1 landslide,and 2 ground collapses,accounting for 89.24%,7.53%,1.08%,and 2.15% of the total disaster points,respectively.Geological disasters in Liuhe County are mainly distributed in hilly areas,with fewer in plain areas;From the perspective of administrative divisions,Liuhe Town has the most geological disasters,followed by Liangshuihezi Town and Xiangyang Town,and Wudaogou Town and Hengtong Town have the least geological disasters.2)Based on the analysis and research on the distribution and development law of geological disasters in Liuhe County and the formation conditions,and in combination with the actual situation of Liuhe County,ten evaluation factors including elevation,gradient,slope aspect,engineering geological rock formation,tectonics(distance from the structure),vegetation coverage,river system(distance from the water system),geomorphic type,rainfall,and road(distance from the road)are selected,and two models of random forest and support vector machine are selected for modeling,Through model optimization,the regionalization results based on the random forest model are selected to analyze the geological hazard risk of Liuhe County,and Liuhe County is divided into four risk grade areas: low,medium,high and extremely high.3)Through the analysis and research of geological disaster bearing bodies in Liuhe County,combined with the actual situation of the research area.Select six evaluation factors including population density,construction land,arable land,forest land,grassland,and road traffic to establish a vulnerability evaluation system.Using the Analytic Hierarchy Process and Arc GIS natural discontinuity points,Liuhe County is divided into four vulnerability level areas: low,medium,high,and extremely high.4)Geological hazard risk assessment in Liuhe County,based on the empirical formula "R(risk degree)=H(risk value)× V(Vulnerability Value)" is assigned and calculated,and then the Arc GIS grid calculator function is used for superposition calculation.Liuhe County is divided into four risk level areas: low,medium,high,and extremely high.Based on this,relevant suggestions are proposed based on the geological hazard risk assessment results of Liuhe County.