The Landslide Hazard Assessment In Jinsha River Grand Bridge Canyon Areas Of Lixiang Railway

Based on remote sensing interpretation and field survey of landslides,this paper takes the Jinsha River canyon area of Diqing Tibetan Autonomous Prefecture in Yunnan Province as the research area.Spatial regularity of landslide development has analyzed,and geological information database of Jinsha river Gorge is established by using ArcGIS.On the basis of previous studies,considering both geological factors and disaster-inducing factors,eight factors,including slope,fluctuation,stratum lithology,geological structure(distance from fault),River action(distance from river),vegetation coverage,annual average rainfall and human engineering activities(distance from road),are selected to establish an index system for evaluating regional landslide hazards.The contribution of each influencing factor to landslide hazard is evaluated by three mathematical statistical models: information value method,evidence weight method and CF coefficient method.Landslides are mainly developed in areas with gentle slope,large fluctuation and fractured rock strata.They are distributed in zones along Jinsha River,Hutiaoxia fault-Chongjiang River fault zone,and the nearer the distance from road is,the more the quantity of landslides is.The direct superposition method is used to interconnection the evaluation results of each single factor,and the risk assessment of landslide disasters in the study area is obtained.The AUC values of the three models are more than 70%,which indicates that the three models have good accuracy.Among them,the AUC of the information value model is the highest,reaching 80.76%.On the basis of the superposition method,the intensity factor of landslide hazard activity is introduced to the analysis,and landslide point core density and landslide surface core density are increased to the assessment index,which obtain the landslide hazard assessment considering time.Compared with the superposition method,the zoning results highlight the areas where landslides have occurred and weaken the areas where no landslides have occurred.The final landslide hazard zoning map of the study area is obtained by synthesizing the risk assessment of the two zoning results.The final results are in good agreement with the known landslide distribution,which can provide reference for the future development and construction of the area.The Jinsha river Bridge Site is located in the low-risk area,indicating the safety of the bridge site.