Study On Risk Assessment Of Landslide In Yunnan Province

Landslide is a dangerous geological event,which always poses great threat to the safety of human life and property and cause great damage to environment and ecosystem Restricted the sustainable development of human beings.The survey data show that the proportion of landslides in China is in the most destructive event in all geological disasters,which account for 74%.Therefore,it is necessary to take effective evaluation of landslide disaster and it is of great economic and social significance to predict the landslide disaster effectively.After decades of scientific exploration,our country has made gratifying achievements in the study of landslide disasters.However,there are still some problems in the quantification of the self-organized criticality of regional geological disasters and the dependence of frequency and space on the regional geological disasters.Meanwhile,the selection of evaluation factors,risk assessment and the boundary of susceptibility analysis in the vulnerability analysis of landslides also need to be explored and studied.Yunnan province is one of the most frequent geological disasters occurring region in China,geological disasters widely development and distributed,which provides a good basis for the evaluation of the susceptibility and risk of landslide hazard in the large regional scale of the provincial level.In this study,the whole region of Yunnan province is selected as the research area,and the quantitative analysis and evaluation of the characteristics of the landslide disaster in this area are carried out.Multi model evaluation zoning is carried out on the susceptibility and risk of landslide disaster in this area.The main research contents and results are as follows:The characteristics of geological disasters in Yunnan province have been quantitatively revealed.The main types,scale and material composition of geological disasters in Yunnan are analyzed and investigated.The main geological disaster in Yunnan province is landslides,and the debris flow is the next.The disaster occurred mainly occurs from May to October and show strong seasonal characteristics.In the spatial distribution,the landslides are mainly distributed in the northwestern Yunnan region,which is both dispersive and aggregated.The scale and intensity of the disaster development in Yunnan province were quantitatively analyzed,and the material composition of the landslides in the study area was explored.The relationship between the frequency and the scale of the landslides in Yunnan province was quantitatively analyzed,and the self-organized criticality of the landslide and other disasters was analyzed.The fractal and variable dimension fractal characteristics of geological hazards in Yunnan province are revealed.The spatial relationship between the spatial distribution of landslide and elevation,slope and fracture is calculated,and the fractal characteristics of variable dimension are revealed.The relationship between the frequency and the strength of the landslide geological hazard is analyzed.In the selection of cartographic units,the cartographic units are mainly divided into 5 categories: geographical unit,grid unit,terrain unit,slope unit and uniform conditional unit.This study is mainly based on the grid unit to evaluate the landslide geological hazard in Yunnan province.A relatively perfect system for Evaluating Landslide on large scale has been established,and the relationship between landslide hazard and various evaluation factors has been systematically expounded by quantitative analysis and evaluation method.The logistic regression model,information model,evidence of belief model,weight of evidence,and data mining(machine learning)such as Support vector machine model susceptibility evaluation methods of Yunnan province landslide susceptibility assessment were carried out.The landslide prone areas in Yunnan are divided into 5 grades,which are no danger zone,easy hair area,medium prone area,high prone area and high prone area.The advantages and disadvantages of each susceptibility analysis and evaluation model in the analysis of landslide susceptibility in Yunnan province are compared and analyzed systematically,and a comparison method of susceptibility assessment results is put forward.Using ROC curve,KAPPA coefficient and other mature precision evaluation methods,the effectiveness of each model in Yunnan landslide hazard assessment is obtained.The results show that all model are show good performance,support vector machine and evidence weight model are more objective,effective and reasonable.In dangerous analysis,we explored the probability and frequency distribution of landslide hazard in Yunnan Province,and calculated the probability of exceeding area in 5 years and 10 years in Yunnan province by Poisson distribution model.The frequency of landslides is indirectly reflected by the activity of the past landslides.On this basis,combined with the results of susceptibility assessment,and the induced factors such as earthquakes,rainfall and human engineering activities,we use the multiplicative method to divide the risk of landslide hazard in Yunnan into three grades: low risk area,middle risk area and high risk area.According to the results of risk zoning and other factors,measures and suggestions for disaster prevention and mitigation of landslide in Yunnan province are put forward to reduce the property loss caused by landslides.