| Landslide is a serious geological disaster after earthquake and flood.Located in the southwestern margin of the Sichuan Basin,the Xizhou District is a Mesozoic soft and hard interbedded stratum with strong geological tectonic activities and diversified stratigraphic lithology.In addition,the area is rich in rainfall and landslide disasters are more developed,but the local residents ’ awareness of disaster prevention is low,causing casualties and economic losses to varying degrees.Therefore,it is necessary to combine the regional natural geographical environment conditions,scientifically evaluate the landslide susceptibility in Xuzhou area,and reasonably divide the susceptibility areas,so as to provide scientific basis for the long-term prevention and control of landslide disasters.Based on the first national natural disaster comprehensive risk census project in Sichuan Province,this paper analyzes and studies the development conditions and distribution rules of landslide disasters in the background of Xuzhou District,Yibin City,Sichuan Province.Based on the analysis of the influencing factors of natural geological environment and human engineering activities on landslide,the evaluation index system and evaluation model of landslide susceptibility in Xuzhou District,Yibin City,Sichuan Province are constructed.The research results are as follows :1.The regional background environment and engineering geological conditions of landslide geological disasters in Xuzhou area are analyzed and studied in detail.The development modes and spatial distribution characteristics of different types of landslides are clarified.By analyzing the development conditions and distribution rules of landslide disasters,the relationship between environmental factors and landslide development is established,and the main factors affecting landslide development are obtained.Different factors have different effects on landslide development.2.The influencing factors of landslide disaster in Xuzhou area were analyzed and studied,and the landslide disaster susceptibility evaluation system including slope,elevation,rock dip angle,land use,road,water system,slope structure and geological rock group was screened and constructed.Based on GIS database,information model,AHP-information coupling model and Logistic-information coupling model,the landslide susceptibility of Xuzhou District in Yibin City,Sichuan Province was divided and evaluated.3.Based on the ROC curve,the evaluation zoning results of the three models were compared and analyzed.The AUC values corresponding to the ROC curve of the information quantity,AHP-information quantity and Logistic-information quantity landslide susceptibility evaluation model were 0.785,0.800 and 0.814,respectively.According to the results of the Logistic-information coupling model,the susceptibility of landslide disasters in Xuzhou District is divided into five grades : extremely high,high,medium,low and extremely low.The western and southern regions of Xuzhou have the highest susceptibility to landslides,and the extremely high and high susceptibility areas account for 30.97 % of the total area.The area of Yuexi River in the northern part of the study area is not prone to landslide disasters,and the area of low and very low susceptibility areas accounts for 54.03 % of the total area of the study area.Moderately prone areas account for 14.99 % of the total area of Xuzhou. |
PDF Full Text Request