Analysis of landslide deformation in eastern Qinghai Province, Northwest China, using SBAS-InSAR

In eastern Qinghai Province, China, landslides are a frequent hazard, yet their large-scale monitoring and assessment are under-researched. This study utilized 31 Sentinel-1A satellite images from January 4, 2020, to August 9, 2022, and applied the Small Baseline Subset Interferometry Synthetic Aperture Radar (SBAS-InSAR) method to quantify surface subsidence and infer landslide deformation rates in the Loess Plateau. We identified 491 hazardous landslides, with 14 posing significant risks to the Yellow River, major highways, and over 10,000 residents. The average line-of-sight (LOS) surface displacement rate was 118 mm/year, peaking at 298 mm. Satellite imagery revealed rapid and continuous landslide front activity. The landslides' uneven distribution aligns with the area's complex geology and environment, predominantly occurring on 20°–40° slopes with the Normalized Difference Vegetation Index values below 0.3, and aligning with nearby faults in the Hualong basin. Detailed analysis of 14 key landslides showed a marked correlation between landslide movement and monthly precipitation, offering new insights into landslide deformation mechanisms and driving factors.