InSAR identification and monitoring of geological hazards in Ranwu region of Tibet

Southeast Tibet, located in the southeast part of Qinghai-Tibet Plateau, is characterized by steep terrain, frequent occurrence and large scale of geological disasters due to multiple plate tectonic movements and compression movements between rock masses. It’s of great significance to investigate and monitor geological disasters in this region. In this paper, Ranwu area in southeast Tibet is taken as the study area, and the potential disaster points in this area are identified by using sentinel-1A satellite data, and the influence of geometric distortion of SAR image on geological disaster identification is analyzed. Through the analysis of InSAR monitoring results, 67 hidden danger points of landslides and glaciers in the region were delineated. At the same time, in order to better analyze the deformation characteristics and laws of the disaster bodies, three typical glacial disaster bodies in the north bank of Anmuco in Ranwu region were selected, and the two-dimensional (horizontal EAST-west and vertical) deformation rates and time series of the slope bodies were obtained by using multidimensional small baseline subset (MSBAS) technology.Based on the analysis of the deformation time series results of Jiqilong Glacier, Polong Glacier and Waba Village Glacier, it’s found that the maximum cumulative displacement in the horizontal east-west direction from January 2018 to October 2020 is 202 mm, 283 mm and 194 mm respectively. The maximum cumulative displacement in vertical direction is 97 mm, −155 mm and −163 mm respectively. In the horizontal direction, the three typical glaciers show an accelerated deformation trend and slow creep deformation trend in vertical direction. At the same time, the correlation between the two-dimensional deformation time series of Wabacun glacier and precipitation and temperature is analyzed. The results show that the variation of precipitation and temperature has certain influence on the deformation of slope glacier. The research results of this paper have a good reference value for the identification of geological hazards in alpine and canyon areas.