| Fujian Province is one of the areas with frequent occurrence of geological disasters in China,and the northwest of Fujian Province is an area with serious development of geological disasters.Mingxi County is located in the mountain area in the northwest of Fujian Province.The terrain fluctuates greatly,the slope is large,and the landform is deeply cut.In recent years,with the frequent occurrence of extreme weather and the increasing number of human engineering activities,geological disasters in this area have intensified,seriously endangering people’s life and health and property safety.This paper takes the geological disasters in Mingxi County as the research object.On the basis of collecting data and consulting relevant literature,combined with field survey,this paper analyzes the types,development scale,distribution law and influencing factors of geological disasters.The correlation analysis between the influencing factors of geological disasters and the distribution of geological disasters in the study area is used as an important basis for the selection of evaluation factors.Information value model(I)is widely used in the evaluation of geological disaster susceptibility because the evaluation results are objective and reliable,but it can not reflect the impact of various factors on geological disasters.In order to solve this problem,some scholars proposed to make up for the lack of information model by giving the weight of evaluation factors.Therefore,based on I,analytic hierarchy process(AHP)and logistic regression model(LR)are selected to improve to form the improved evaluation model: analytic hierarchy process information value model(AHPI)and information value coupling logistic regression model(LR-I).I,AHP-I and LR-I are applied to the evaluation of geological disaster susceptibility.By comparing the evaluation effects of the three models,the most suitable evaluation method for geological disaster susceptibility in Mingxi County is selected.The main achievements are as follows:(1)The types of geological disasters in Mingxi County are landslide and collapse,which are characterized by small scale but strong harm.This paper systematically combs the distribution law of disasters in time and space.The spatial distribution characteristics show that geological disasters are densely distributed in the west,northwest and northeast of the county.The temporal distribution characteristics show that the rainfall concentration period from April to June every year is the time period of high incidence of geological disasters.(2)Fully consider the influencing factors of geological disasters in the study area,and select 8 influencing factors such as elevation,slope,slope direction,engineering geological rock group,fault structure density,road network density,vegetation coverage and rainfall.Analyze the correlation between various factors and geological disasters and verify the correlation between various factors to ensure that the selection of evaluation factors meets the requirements of rationality and independence,and also lay the foundation for the next susceptibility evaluation.(3)IM,AHP-IM and LR-IM are applied to the evaluation of geological disaster susceptibility to verify and compare the rationality and accuracy of the evaluation results of each model.Rationality comparison results: AHP-IM and LR-IM have good rationality,while the rationality of model I is relatively poor.Accuracy comparison results: LR-IM has the highest evaluation accuracy,while AHP-IM is not as accurate as IM.The rationality and accuracy of LR-IM evaluation results are better than IM;Although the rationality of AHPIM is better than IM,the evaluation accuracy is slightly lower than IM.It is concluded that LR-IM has the best evaluation effect and is suitable for the evaluation of geological disaster susceptibility in Mingxi County.However,the improvement effect of AHP-IM is not reflected in the evaluation results. |
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