| China is one of the most seriously affected countries by geological disasters in the world.In the past decade,the landslide disasters in China accounts for 72.4% of all geological disasters.The monitoring and prevention of landslide disasters have become an urgent task.Traditional landslide monitoring technology is susceptible to the influence of various factors such as topography and climate,and there is a problem that the monitoring points are sparsely distributed,which cannot well reflect the overall deformation of the landslide.It cannot meet the monitoring and prevention needs of large-scale landslides.The study area is located near the Jinsha River Basin at the junction of Jiangda County in Tibet Autonomous Region and Baiyu County in Sichuan Province.By studying the threedimensional historical deformation of the landslide that has occurred,the government can have a more comprehensive and scientific understanding of the local surface deformation.Judging the stability of the landslide based on the landslide deformation monitoring data will provide a scientific basis for the monitoring and prevention of landslide disasters.Three kinds of remote sensing monitoring technologies,including False Color Composite,SBAS-InSAR and Offset-Tracking,are applied to the landslide deformation monitoring,the extraction of three-dimensional deformation field and Stability analysis of landslide are explored simultaneously in this paper.The research results and conclusions are as follows:(1)From the monitoring results of landslide by False Color Composite technology,it's found that the change contour of ground features is clear.The landslide area is in a state of continuous deformation at various stages of historical deformation development,the regional changes are relatively clear and the effect of visual interpretation is good.(2)Based on 30 sentinel-1 SAR images,the one-dimensional deformation of Baige landslide from July 2015 to September 2018 is obtained by using SBAS-InSAR technology.The results show that the monitoring results which based on ascending and descending orbit data are different due to terrain,satellite heading and other factors.Several characteristic points are selected at the front,middle and back edge of the landslide to analyze the onedimensional deformation characteristics of Baige landslide.It's found that the Baige landslide had a large deformation from July 2015 to December 2015,and the deformation rate accelerated significantly from January 2018.(3)Offset-Tracking technology is applied to the two-dimensional deformation field extraction of landslide,the accuracy of monitoring results is not as good as SBAS-InSAR technology.By comparing the deformation in LOS direction of SBAS-InSAR with that in distance direction of Offset-Tracking,it's found that the landslide profile deformation trend is similar,which proves that Offset-Tracking technology is reliable for large-scale landslide monitoring.(4)In the study of landslide three-dimensional deformation field extraction,the paper compares the calculation accuracy of Helmert variance component estimation weighting scheme,equal weight scheme and formula weighting scheme,the results show that Helmert variance component estimation weighting scheme is more scientific and reasonable in data fusion weighting,and it can effectively improve the calculation accuracy.(5)The stability of Baige landslide and the area II of Jinpingzi landslide is analyzed by using the method of two parameter landslide stability judgment.The results show that Baige landslide is in a state of instability before the landslide,the area II of Jinpingzi landslide is in a good state of overall stability,most of the area is in the creep stage,and the two kinds of landslide stability judgment results are basically consistent with the actual situation. |
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