Geological Disaster Susceptibility Assessment In Mengyin County Based On Multi-source

Mengyin County,Linyi City is a mountainous area,where the landform environment is complex.And geological disasters occur frequently in this area,which seriously endangers the safety of people's lives and property.Carrying out regional geological disasters susceptibility evaluation can find out the grade and the susceptibility of regional geological disasters in key areas,which is the focus of current geological disasters prevention and emergency management work.This measure will help researchers to know the susceptibility of regional geological disasters objectively,and put disaster prevention and mitigation materials in a targeted manner,so as to achieve the purpose of protecting people's lives and property.The accuracy of the susceptibility evaluation results determines the proportion of emergency materials allocation,so it is very important to use an appropriate evaluation model.This research takes Mengyin County as the research area.Based on 82 geological disaster points in Mengyin County and the collected multi-source data sets,the spatial distribution characteristics and disaster-pregnancy conditions of the geological disasters in Mengyin County are analyzed.Analytic hierarchy process(AHP)-information model,multi-layer perceptron(MLP)model and random forest(RF)model are used to calculate and predict the susceptibility of geological disasters in Mengyin County,and the accuracy of the susceptibility zoning results of the three models are evaluated.The most accurate susceptibility zoning results are used to evaluate and analyze the susceptibility of geological disasters in Mengyin County.The research results are as follows:(1)By analyzing the status quo of geological disasters in the study area,elevation,slope,slope aspect,lithology,normalized vegetation index(NDVI),rainfall,distance from fault,distance from road and distance from hydrographic net are selected as evaluation factors to construct susceptibility evaluation factors system of geological disasters in Mengyin County.The distribution of geological disasters in each evaluation factor zone are statistically analyzed.Analysis results show that geological disasters in Mengyin County are mainly distributed in the region with the following characteristic:elevations of 227 m-589 m,slopes of 4.84°-25.91°,slope aspects of 22.5°-202.5°,hard lithology or soft lithology,NDVI of 0.32-0.66,distance from the fault within 8745 m,distance from the road within 4019 m,rainfall of 785 mm-798 mm,and distance from the hydrographic net within 3237 m.(2)Based on the above analysis results,AHP-information model,MLP model and RF model are constructed respectively to predict the susceptibility of geological disasters in Mengyin County.First,the weight and information value of each evaluation factor are calculated,and the susceptibility zoning map based on the AHP-information model is obtained by weighted overlay analysis.Secondly,a sample data set is constructed,in which 82 geological disasters points in the study area are used as positive samples,and 82 points are selected randomly in the non-risk regions of the AHP-information model susceptibility partition results as negative samples.The sample data set is used for the training and testing of MLP model and RF model.Finally,the trained model is used to predict the susceptibility of geological disasters in the study area,and the susceptibility zoning maps of geological disasters based on MLP model and RF model are obtained respectively.(3)By comparing the susceptibility zoning map of the three models,the proportion of geological disaster points in the susceptibility zoning results,the density of geological disaster points in the susceptibility zoning results,and the subject characteristic curve,the accuracy of the three susceptibility zoning results based on the above models is evaluated.The result shows that the three models have achieved good prediction results in the susceptibility evaluation of geological disasters in Mengyin County.Furthermore,RF model has the highest prediction accuracy,and AHP-information model has the lowest prediction accuracy.(4)The RF model with the highest accuracy is finally selected to evaluate the susceptibility of geological disasters in Mengyin County.The area of high-risk regions is about 164.11 km~2,accounting for about 10%of the total area of Mengyin County.most of high-risk regions are located in Daigu Town,Yedian Town,Tanbu Town and Jiuzhai Town.The landform type in these regions is mainly Zhongshan hills.There are Daigu landforms which is one of the five major landforms.The susceptibility of geological disasters in the high-risk regions is affected by the geographical environment and should be paid attention to in the process of geological disaster prevention and control.The area of medium-risk regions is about 281.96 km~2,accounting for about 17%of the total area of Mengyin County.And the medium-risk regions are mainly distributed around the high-risk regions.The area of low-risk regions is about 316.18km~2,accounting for about 20%of the total area of Mengyin County.The area of non-risk regions about 849.09 km~2,accounting for about 53%of the total area of Mengyin County.