Detection and Mapping of Active Landslides before Impoundment in the Baihetan Reservoir Area (China) Based on the Time-Series InSAR Method

Abstract

Many potential landslides occured in the Baihetan reservoir area before impoundment. After impoundment, these landslides may still slide, affecting the safe operation of the reservoir area (e.g., causing barrier lakes and floods). Identifying the locations of landslides and their distribution pattern has attracted attention in China and globally. In addition, due to the rolling terrain of the reservoir area, synthetic aperture radar (SAR) imaging will affect the interactive synthetic aperture radar (InSAR) deformation results. Only by obtaining effective deformation information can active landslides be accurately identified. Therefore, the banks of the Hulukou Xiangbiling section of the Baihetan reservoir area before impoundment in the Jinsha River Basin were studied in this paper. Using terrain data and the satellite parameters from Sentinel-1A ascending and descending orbits and ALOS PALSAR ascending orbit, the line-of-sight visibility was quantitatively analyzed, and an analysis method was proposed. Based on the SAR data visibility analysis, the small baseline subset (SBAS) technique was used to process the SAR data to acquire effective deformation. InSAR deformation data was combined with Google Earth imagery to identify 25 active landslides. After field verification, 21 active landslides (14 new) were determined. Most of the active landslides are controlled by faults, and the strata of the other landslides are relatively weak. This InSAR analysis method based on SAR data visibility can provide a reference for identifying and analyzing active landslides in other complicated terrain.

Automatic Identification of Slope Active Deformation Areas in the Zhouqu Region of China With DS-InSAR Results

“…When illuminated towards the satellite, foreshortening (c-d) occurs when the slope angle is less than or equal to θ, and layover (b-a) occurs when the slope angle is greater than θ. When backward facing the satellite, shadowing (g-h) occurs when the slope angle is greater than 90 − α (Dun et al, 2021).…”

Combining InSAR Technology to Uncover the Deformation Factors and Mechanisms of Landslides in the Baihetan Hydropower Station Reservoir Area

“…InSAR technology, however, offers broad area detection and frequent monitoring, with proven benefits in landslide detection [33][34][35][36]. Yet, its application in steep areas encounters issues like terrain and atmospheric effects [37]. The small baseline subsets (SBAS) technique mitigates these effects, enhancing measurement accuracy [38].…”

Numerical simulation of potential impulse waves generated by Mogu toppling rock slope at varying water levels in Lianghekou Reservoir, China

“…Recently, with the impoundment of the Baihetan Reservoir, the Wangjiashan landslide and Tuandigou landslide have deformation at different levels (Chen et al 2023a, Cheng et al 2023. Landslides induced by reservoir impoundment have gradually become a contentious issue in Baihetan Reservoir (Dun et al 2021, Liu et al 2021. Due to the strong destructive impulse waves of reservoir landslides, researchers worldwide are actively exploring the impulse wave triggered by potential reservoir landslides is evaluated.…”