Research On Application Of InSAR Technology In High-level And Long-distance Landslide Recognition And Monitoring In Jinsha River Basin

With the continuous progress of science and technology and the continuous expansion and deepening of the scope of human engineering activities,mankind is facing a more severe natural environment and frequent natural disasters.As a widely distributed natural disaster in our country,landslides not only threaten people's lives and property safety,but also pose a series of huge challenges to the design,construction and construction of major national projects.The Sichuan-Tibet Railway,as a major regional transportation strategic project in my country,passes through the study area of this article—the Zhubalong-Shigu section of the Jinsha River.This area is the high-and long-distance landslide disaster high-prone area and prone area,so it is of great practical significance and urgent need to carry out the identification and monitoring of highdistance landslides in this area.Interferometric Synthetic Aperture Radar(InSAR)is a new earth observation technology.Due to its advantages in all-weather,large-scale,span-time,and highprecision,it has widely used in the early recognition and monitoring of landslide hazards in recent years.However,when the identifying and monitoring of this kind of hazards along the river basin,it will be faced with some difficulties,such as overlap and shadow formed side-view radar imaging in SAR images,and the dense vegetation and snow cover.These will result in low coherence of InSAR interference.The influence of the atmosphere seriously obscures the signal,causing missed judgments and misjudgments of hidden danger points.Therefore,this paper relies on the project of China Geological Survey "Integrated Application of Major High-level Remote Geological Hazard Prevention Technology"(No.: DD20190637),and takes the Jinsha River Basin(from Zhubalong to Shigu)as the experimental area.Using InSAR technology to carry out early identification and monitoring of high and long-landslide hidden danger in the Yangtze River basin,which provides a reference for geological disaster investigation and monitoring in high mountain and canyon belt.Specific research contents and results are as follows:(1)We summarized the principles of the sequential InSAR technology used in the identification and monitoring of landslide hazards;focused on the geometric effect,interference coherence and atmospheric interference on monitoring and identification high-level and long-distance landslide of InSAR Technology,corresponding improvement measures are given,and the feasibility of the improvement measures is verified through experiments;(2)Using the 336 Sentinel-1A images covering the Jinsha River Basin(from Zhubalong to Shigu),we carried out surface deformation monitoring along this river,and obtained a map of the average annual deformation rate by Stacking and SBAS technology in this region;(3)With the help of GIS spatial analysis technology,combined with InSAR monitoring results and optical images,a total of 62 landslide hazards were identified.And the spatial distribution characteristics of landslide hidden danger points were statistically analyzed.The results showed that the landslide hazards in this area are more distributed in the East Bank of Jinsha River.This was because ascending datasets were in the overlapping area in most areas of the East Bank of Jinsha River.So the number of landslide hazards identified by descending datasets was higher than that identified by ascending datasets in this area,which proved the importance of monitoring this kind of landslide from different angles;(4)We took the Zhongxinrong Township landslide group in the center of the Batang section of the Jinsha River junction as the experimental area,and obtained the deformation rate and deformation time series of the typical landslide in the east-west and vertical directions by MSBAS-2D technology.The deformation information of the Zhong Xin Rong landslide group was acquired from multiple angles,and the time series of Gonghuo Village landslide 2# and rainfall data were used to analyze the influence of rainfall on the deformation rate and stability of landslide.