| The Qinghai-Tibet Plateau is located in a geological tectonic area and is also a highincidence area of geological disasters.Due to its complex topography and high mountains and deep valleys,it is extremely difficult to carry out traditional monitoring,which hinders the understanding of landslides in the region,and thus lacks local landslide disaster prevention and mitigation measure.The Karuo District of Changdu,Tibet Autonomous Region is located in the Lancang River system.The collapsed debris slips into the river,and it is easy to form a dammed lake.The collapse of the dammed lake will cause serious secondary disasters and be extremely destructive.The geological conditions in this area are complex,with vertical and horizontal valleys,serious river cuts,and the topsoil is dominated by loess,which is prone to landslides and other geological disasters.Therefore,the early warning and prevention of landslide disasters in alpine and gorge areas are particularly important.For the inaccessible alpine and canyon areas,it is necessary to give full play to the advantages of the "eye of the sky".The observation technology based on satellite remote sensing has become an important means of obtaining environmental variable data in geological disaster areas.Surface deformation is an important reflection of landslide activity.Landslide displacement data provided by mature Interferometric Synthetic Aperture Radar(In SAR)technology can be further used to investigate landslide mechanisms,including landslide types,triggering factors,failure modes,and estimated depths,volume,so as to be used for landslide disaster risk assessment,which is an important means of disaster prevention and mitigation at this stage.Based on the evaluation of landslide susceptibility and the identification results of Synthetic Aperture Radar Interferometry Stacking(Stacking-In SAR),this paper focuses on a typical landslide—Yueda Village landslide as an example.SBAS-In SAR technology was used to monitor the long-term displacement characteristics of the landslide in Yueda Village,and combined with its disaster-pregnant environment to analyze the cause of the landslide.The results of the study are as follows:(1)The evaluation results of landslide susceptibility in Karuo District based on the weighted information method show that the landslide susceptibility in Karuo District is higher in the north and lower in the south,and the northwest region is the most prominent.Based on the susceptibility evaluation results,the Stacking-In SAR early identification of landslide-prone areas was carried out.The study found that the potential landslides in the Karo area are mainly distributed in the northwest area,and these areas are in an unstable state.Monitoring and prevention are imperative.(2)In 2018,several landslides occurred in Yueda Village,Karuo District,with a large vertical height difference,which is a typical high-level landslide.The results of the landslide lineof-sight(LOS)displacement data based on the radar data monitoring of the lifting rail show that the landslide in Yueda Village has obvious deformation,and the deformation rate under the lifting rail can reach 148 mm/a and 94 mm/a,respectively.The area of the detected deformation regions is the same,and they all show an obvious linear acceleration state;however,due to the different working modes of the elevating orbit satellites,there are certain differences in the maximum line-of-sight deformation rates detected by the two datasets.(3)The causes of landslides are analyzed by the landslide displacement data monitored by SBAS-In SAR.The landslide in Yueda Village,Karuo District is a high-level landslide.Affected by continuous heavy rainfall,historical earthquakes and geological structures,the acceleration of continuous heavy rainfall in summer has accelerated the occurrence of landslides.The geological environment of Karuo District,Changdu City is very fragile,and geological disasters such as landslides are very prone to occur,so monitoring and prevention need to be strengthened. |
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