Risk Assessment Of Debris Flow Along The North Line Of Sichuan-Tibet Highway

This paper is taking debris flows along the northern line of the Sichuan-Tibet Highway as the research objective.Based on the comprehensive collection of the environmental background of the study area and the existing debris flow disaster data,studied the generating background and conditions of the debris flow on the northern line of the Sichuan-Tibet Highway by the field survey and remote sensing Interpretation and other means;analyzed the distribution,development and hazard characteristics of the debris flow;selected the debris flow risk assessment indicators and road accessibility in the study area;Used the GIS platform to complete the risk assessment of debris flow on the northern line of the Sichuan-Tibet Highway.The main results achieved are as follows:1.Interpreted the debris flow along the northern line of the Sichuan-Tibet Highway,collected the environmental background of the study area and the existing debris flow disaster data to find out the disaster-generating environment and disaster conditions of the debris flow in the area;organized the field survey data and analyzed the spatial distribution,development characteristics,and disaster-causing characteristics of internal debris flows;laied the foundation for subsequent risk assessment.2.Based on the weight of evidence analysis method,the key factors are selected in combination with the disaster-generating environment and inducing factors of the debris flow in the study area,and the dangerous zoning of the highway lithological debris flow is completed.The results show that the debris flow along the northern line of the Sichuan-Tibet Highway accounted for 90% of the high-risk areas,mainly distributed in the Qamdo area,Jiangda county and Daofu and Luhuo counties.3.Analyzed the damage mode of the debris flow on the northern line of the SichuanTibet Highway and the structural characteristics of the highway structure,and adopt the analytic hierarchy process to realize damage zoning of the northern line of the SichuanTibet Highway from three aspects,which consist of the exposure of disaster-bearing body,the attribute characteristics,and the resilience of the disaster.The results showed that the middle and high vulnerable sections along the northern line of the SichuanTibet Highway accounted for nearly 65%,mainly distributed in Ruyi Township and Ritong Township in Qamdo,Kagon Township in Jiangda County,Keluodong Township in Dege County,and Ganzi County.Zhixiang-Juwo Township section,Luhuo County to Daofu County section.4.Comprehensively integrated the hazard of the disaster-causing body debris flow and the vulnerability of the disaster-bearing body road,adopted a multi-index comprehensive evaluation model,and used Arc GIS spatial analysis technology to quantitatively evaluate and regionalize the debris flow risk on the northern line of the Sichuan-Tibet Highway.The results showed that the high-risk sections along the northern line of the Sichuan-Tibet Highway accounted for more than 60%,which were severely affected by mudslides,mainly in the Qamdo area,near Jiangda,Dege,and Daofu-Luhuo section.In summary,the risk assessment of the debris flow along the northern line of the Sichuan-Tibet Highway was carried out from the two aspects of debris flow hazard and road vulnerability,combined with the formation conditions of the debris flow,further analysis of the difference in risk levels of each section of the road.The research results can provide references for the reconstruction and improvement of existing SichuanTibet lines,disaster reduction and prevention,and debris flow disaster risk management.