Detecting Tange landslide deformation and disaster chain effects: an integrated approach using SBAS-InSAR and massflow simulation in the hazardous Dongzha River Basin, Tibetan Plateau
摘要
The upper Jinsha River region is characterized by complex terrain, landforms, and climatic conditions, resulting in a high prevalence of large landslides. The sudden nature of their formation makes early detection and mechanism research particularly challenging. This study employs SBAS-InSAR algorithm, aerial imagery (from google earth) interpretation, UAV photogrammetry, field reconnaissance, and numerical simulations to understand the kinematics, mechanisms and possible triggering factors of Tange landslide in the Dongzha River basin. Remote sensing analysis reveals the Tange landslide exhibited significant deformation following intense rainfall in July 2018. The front of the landslide developed a strong deformation zone with a maximum displacement rate of -87.2 mm/yr and a cumulative displacement reaching 590 mm. The study highlights that heavy rainfall significantly affects the deformation of the Tange landslide. Fault creep has facilitated the formation and expansion of surface fractures, creating favorable pathways for rainfall infiltration. The deformation pattern of the landslide is characterized under rainfall influence. According to Massflow simulations, the sliding mass in the Tange landslide’s strong deformation zone can reached the base of the slope in just 10.1 s. It could travel up to 2.14 km, with a maximum accumulation thickness of 43.1 m and 53.89 × 104 m2. Prolonged blockage of the Dongzha River could create a landslide dam, causing backwater flooding of upstream roads and villages, and potentially triggering more extensive slope deformation and damage on the Dongzha River. The findings offer valuable insights for disaster prevention in the mountainous canyon areas of the Tibetan Plateau.