Landslide Risk Assessment Based On Combined Analysis Of Weight Method And Simulation Method

Relevant evaluation and analysis on the vulnerability,risk and harmfulness of landslide disasters are of great practical significance to the stable life of human beings,the modernization of cities and the sustainable development of the country.Among them,regional landslide risk assessment is an important part of landslide disaster prevention and control research.Since the early 1960 s,regional landslide risk assessment methods have developed from semi-quantitative analysis to quantitative analysis.However,it is difficult to explain the contribution degree and mechanism of influence factors to landslide at the same time by analyzing the weight calculation results of various influence factors of landslide disasters and the probability calculation results obtained through the safety factor model.Therefore,in the specific landslide disaster area,how to combine semi-quantitative analysis method with quantitative research method to obtain more reasonable and accurate evaluation results is the main research purpose of the paper and the core problem to be solved.Sichuan Province is one of the regions with the most frequent geological disasters in our country,with a wide distribution of disaster points,which provides a good foundation for the study of landslide hazard susceptibility and risk assessment.In this study,part of Wanyuan City in Sichuan Province is selected as the research area,and relevant information such as geological environment data in the research area is obtained and analyzed through data collection and indoor experiments.The research results are as follows:(1)Combining contribution weight model and analytic hierarchy process,the weight of landslide impact factors is calculated,and dominant factors are selected and landslide risk evaluation results are given accordingly;The safety factor model established by the simulation analysis method is used to calculate the cumulative displacement of the slide block,and the landslide hazard zoning result is obtained from the calculation result of excess probability.The dominant factor of landslide influencing factors is selected for weight analysis,and combined with slider cumulative displacement model calculation,the landslide hazard zoning result of comprehensive evaluation by weight and simulation method is obtained.Finally,it compares the evaluation results of the two single methods and summarizes the reliability,advantages and disadvantages of the two methods.(2)Reasonable selection of dominant factors can greatly reduce the repeatability of influencing factors in the process of joint evaluation.Combining AHP and contribution weight method to select dominant factors among multiple landslide influencing factors,the reliability can be tested by historical landslide catalog data.(3)The landslide risk evaluation results based on the weight method have a high coincidence degree with the actual historical landslide distribution in the macro area;The landslide hazard analysis results based on simulation method can better predict the distribution of landslides with different hazard degrees in the region.The evaluation results analyzed by the combined weight method and simulation method are not only highly coincident with the actual historical landslide distribution,but also more consistent with the actual situation,which is conducive to enhancing the accuracy and rationality of the evaluation results.(4)Through the analysis of the results of the three evaluation methods,it can be seen that the serious landslide areas are distributed in the intersection of the north of Wanyuan City and the south-central part of Lishu Township,the middle part of Shitang Town and the south-central part of Iron Mine Town,the west part of Shitie Township and the intersection of the two,the areas of Qinhe Township,Hekou Town and Shiwo Town in the southwest of the research area,Zhuyu Town,Xindian Township and Shiluo Township in the northwest of the research area,and the landslide risk levels in the central part of Qinghua Town and Miaopo Township in the northeast of the research area are also relatively serious.