Research on early identification of geological hazards in high mountain and valley areas of western Sichuan Province based on InSAR technology: A case study of Xiaojinchuan River Basin

Short Baseline Set Time-Series Interferometry (Small Baseline Subset InSAR,SBAS-InSAR) technology is used to carry out research on surface multi-temporal and long time-series deformation monitoring and early identification of potential geological hazards in the high mountain and valley areas of western Sichuan, combining with the multi-temporal synthetic aperture radar data. The principle of the time-series InSAR method is introduced and the data processing process is sorted out. Besides, the radar visibility of Xiaojinchuan River Basin is analyzed, and the surface deformation monitoring in the basin is carried out using 26 periods of Sentinel-1A historical archived data from November 2018 to December 2019. The results show that the accumulated deformation in the radar line of sight direction in the basin reaches -51.12—75.28 mm/a. 4 deformation anomalies and 11 potential geological hazards were identified based on the distribution pattern of deformation anomalies, including 6 known geological hazards and 5 unknown geological hazards. Taking P1 (Aniangzhai landslide) as an example, the authors in this paper have carried out the long time series monitoring analysis and verification. The reliability of using InSAR technology for early identification of geological hazards were identified to prove the advantages and effectiveness of SBAS-InSAR technology in early identification of geological hazards, which has the potential for wide-scale application in the high mountain and valley areas of western Sichuan.