Landslide Risk Assessment Based On The Conjoint Analysis Of Weight And Probabilistic Methods

Because landslide frequently cause serious loss,to study its probability is significant to promote the development of urbanization and harmonious society.The regional risk assessment of landslide is the first stage in the prevention and treatment plans of relative disasters.In 2013,Minxian-Zhangxian Earthquake in Gansu induced more than 600 landslides mainly loess landslides,which caused serious casualties and economic losses.No matter how to make assessment to the landslide risk,the weight analysis of many factors or the probability analysis based on the safety factor calculation model,it is difficult to explain the contribution degree of disaster causing factors to landslide and the mechanism.In the specific research area,the main purpose of the thesis and the core problem to be solved is how to combine the weight method with the probability method to get more reasonable and reliable evaluation results.Combining the contribution weight model and the three scale two AHP weight analysis to analyze the weight of landslides influencing factors,the author obtained dominant factors and presented the landslide hazard assessment results.The cumulative displacement was calculated by analysis of safety coefficient model established by probability method,the zoning results of landslide risk were obtained by conjoint analysis of weight and probability method depending on dominant factors and cumulative displacement model.Compared with evaluation results of the weighting method and probability method,the possible advantage of conjoint analysis is revealed.The research results are summarized as follows.(1)The dominant factors were chose through two kinds methods of the two step three scale analytic hierarchy process and the contribution weights,and its rationality was verified by the actual landslide distribution results.The advantage of dominant factors selection is to avoid the repeatability of influencing factors in the joint process of weighting method and probability method.(2)The weighting method results of landslide risk evaluation coincided with actual existing landslide distribution,which verifies the rationality of the weighting method results.The probability method results predicted the future distribution of different grades landslide well.The joint evaluation method not only has a high degree of coincidence with the existing landslides,but also makes the joint results more realistic and reliable.(3)Comparing the results of the three assessment methods,this study could make sure six landslide hazard sub-areas belonging to severity area,which need to strengthen disaster prevention measures,including the central and northwest of Wushan county and the junction with Zhangxian and Longxi,the south of Weiyuan and the junction of Zhuoni and Lotus Hill scenic forest protection area,northwest of Minxian and its border with Lintan,the south central of Tanchang and eastern Zhouqu,the east central of Lixian and its border with Xihe,and the junction of Tongwei and Gangu.