Research On Risk Assessment And Disaster Mitigation Of Geological Disasters In Dalian

In the context of global warming,changes in the geographical environment have increasingly significant impacts on human life.The rapid development of society and economy,the increase of population density,the increasing losses caused by geological disasters,and the increasing demand for disaster prevention and mitigation.Research on the occurrence mechanism and risk assessment of geological disasters is the prerequisite and basis for disaster prevention and mitigation.There are 74 large and extra-large geological disasters in Dalian.The risk level of geological disasters is relatively high,threatening a total of 36611 people and threatening assets of 754.23 million yuan,to carry out the research on the risk assessment and mitigation of geological disasters in Dalian,which has certain theoretical reference value for the prevention and mitigation of geological disasters in Dalian.Based on field surveys and reference materials related to geological hazards in Dalian,the risk assessment of geological hazards in Dalian with the help of Arc GIS for 745 geological hazards in Dalian is compared with the analytic hierarchy process,information volume method,and combined weighting method.Methods and comparisons show that the combined weighting method is more suitable for the risk assessment of geological disasters in Dalian,and preliminary research measures for disaster mitigation are proposed based on the characteristics of geological disasters and risk zoning in Dalian.The main results are as follows:(1)Analyze the distribution and development characteristics of geological disasters.Show the spatial and temporal distribution pattern of major geological disasters in Dalian,analyze the occurrence mechanism and distribution characteristics of the four major geological disasters in Dalian,including collapse,landslide,debris flow and ground subsidence,and select distinctive cases for analysis,and analyze the distribution of geological disasters in Dalian The rules and developmental characteristics are summarized.(2)Determine the evaluation factors to build an evaluation system.Collecting and sorting out relevant data about Dalian's geological disasters,obtaining information about the study area's elevation,slope,aspect and land use types through remote sensing interpretation,and GIS-based spatial analysis and management functions for the topography,river systems,and rocks of Dalian Analyze the stratum,climate and weather,vegetation distribution,etc.,and determine the hazard factors as slope,aspect,land use type,stratum lithology,main fault zone distance,annual average precipitation for many years,and distance from the river based on the principle of selection of evaluation factors.The eight indicators of the distance from the road are mainly divided into two categories: basic factors and inducing factors to construct an evaluation system.(3)Risk assessment and inspection by zoning.By analyzing the hazard points and selected factors,using the analytic hierarchy process,the information volume method and the combined weighting method to evaluate its risk,using the ROC curve,verifying the accuracy of the three methods for the evaluation of geological hazards in Dalian,and comparing It is concluded that the combined weighting method is the most suitable method for evaluating the risk of geological disasters in Dalian.(4)Propose disaster reduction methods.Based on the results of the risk assessment of geological disasters in Dalian,and in accordance with relevant principles of disaster reduction,we propose disaster mitigation methods for geological disasters in Dalian,including disaster avoidance,engineering,establishment of monitoring systems,and geological environmental protection.The design of disaster mitigation schemes is initially proposed,and zoning prevention and control are proposed for different regions.Countermeasures.