Landslide Risk Dynamic Evaluation Of The Basu Segment Of The State Grid In Tibet

The Tibet region is a high-risk area for geological disasters in China,which has a harsh climate,complex terrain,and geological structural development.Landslide disasters,in particular,have the characteristics of large scale,high concealment,high recognition difficulty and complex generative mechanism,which seriously hinder the economic development of this region.Tibet Interconnection Project of State Grid is in this extreme climate and complex geological environment,which has a great impact on the normal operation of Tibet Interconnection Project of State Grid.In order to effectively prevent or reduce the economic losses caused by landslide disasters to transmission projects,in addition to reasonable engineering measures,landslide hazard risk assessment is also a very effective non-engineered disaster prevention and reduction method,which provides an effective theoretical basis for disaster prevention for the normal operation of transmission projects.Relying on the project of Tibet Interconnection Project of State Grid,the Basu section of it was selected as the study area.Based on the development mechanism of landslide disasters and its breeding environment,the basic conditions required for landslide disasters are selected,and the evolution of slope deformation is analyzed to study the dangerous changes in the various stages of slope evolution.Finally,combined with the analysis of vulnerability of transmission lines,a technology for dynamic risk assessment of landslides suitable for networking projects in Tibet is being developed.The details are as follows:1.Through data analysis and field reexamination,the interpretation of landslide hazard in study area will be completed by combining remote sensing interpretation with field investigation.The development characteristics and spatial distribution rules of landslide hazard are quantitatively explained by mathematical statistics.2.Through the the analysis of the development and evolution characteristics of each stage of the slope,based on the conventional risk assessment index system,the active state indicators of slopes are incorporated and a dynamic evaluation index system is constructed.The risk assessment of landslides in the study area is completed using the weighted information method.By optimizing the evaluation model,a landslide risk dynamic assessment model was constructed.3.Comparing various conventional InSAR technologies,SBAS-InSAR technology was selected due to its suitability for evaluation.On the basis of mastering the work flow of interpreting surface deformation information,combined with the downloaded original SAR image data,the interpretation of the four phases of dynamic indicators was completed through the SBAS surface deformation interpretation technology and GIS technology,based on the dynamic risk assessment model.four-stage risk assessment and results analysis was completed.4.Combining with the characteristics of the transmission tower's hazard-bearing body,GIS software was used to intersect the transmission tower position with the slope unit,and divide the research area into the tower position slope unit and the non-tower position slope unit.For the attribute characteristics,exposure and recovery capacity of the tower location,calculate the vulnerability contribution rate of the tower slope unit and classify it into three levels of vulnerability: high,medium,and low,and assign a vulnerability value of 4,3,2 respectively;non-tower slope units have the lowest vulnerability,vulnerability value is 1,In the end,based on the idea of goal,the accounting goal method was proposed to completes the vulnerability assessment of the study area.5.Based on the hazard dynamic assessment and vulnerability assessment analysis in the study area,a risk dynamic evaluation model of landslide hazard was constructed using the model of "risk =hazard × vulnerability".By using the four phases of dynamic evaluation indicators,based on the risk dynamic evaluation model,four phases of risk assessment and results analysis was completed.Then,according to the trend of risk changes,corresponding disaster prevention recommendations were drawn.According to the characteristics of time acquisition of dynamic indicators,a dynamic risk assessment model for landslide hazards is proposed,that is,satellite revisiting time is used as the cycle,and dynamic indicators are updated to complete the dynamic evaluation of landslide risk.