Deformation analysis in the bank slopes in the reservoir area of Baihetan Hydropower Station based on SBAS-InSAR technology

The analysis of potential landslide deformation on the reservoir bank is an important link to ensure the safe operation of national water conservancy and hydropower facilities. In response to the problem of inaccurate monitoring of potential landslide deformation on the reservoir bank using single-track SAR data only, this paper uses SBAS-InSAR technology to construct the radar line-of-sight directional deformation of the study area from July 2019 to July 2021 by combining elevated-track Sentinel-1 SAR data time series, and unmanned aircraft field surveys were combined to analyse the deformation characteristics of typical potential landslides on the reservoir bank of Baihetan hydropower station. The results show that: (1) under the influence of water storage factors, the average growth rate of potential landslide deformation on the reservoir bank of Baihetan hydropower station reaches more than 10 mm/a. Reservoir bank stability is undermined; (2) water storage changes are the key causal factor in the development of reservoir bank potential landslides at present. The potential landslides on the reservoir bank of Baihetan Hydropower Station are at risk of instability with the joint effect factors such as water storage and rainfall; (3) the method which combined lift-track SAR data can effectively overcome the problems such as geometric distortion caused by a single track, and make the monitoring of potential landslide deformation on the reservoir bank of hydropower station more accurate and comprehensive. The research result can help to understand the impact of reservoir storage on the deformation trend of reservoir bank potential landslides, and can provide scientific support for regional-scale disaster prevention and emergency management.