A multi-method framework for hazard assessment of high-altitude landslides: a case study of the Luodexi Landslide on the Eastern Tibetan Plateau
摘要
Global climate change has intensified landslides in high-elevation mountainous regions, with high-altitude landslides posing a particularly significant threat to the safety of mountain communities and infrastructure. However, due to the initiation zone of the landslide with high locations and its concealed nature, the identification and risk assessment of high-altitude landslides face critical challenges. Conventional single-method approaches have become inadequate for comprehensively evaluating such risks. This study proposes a deformation analysis method for high-altitude landslides by coupling ground surface temperature with InSAR-measured deformation characteristics. Furthermore, a multi-method assessment framework for the hazard assessment of high-altitude landslides is established. Using the Luodexi landslide in Baiyu County, Sichuan Province, China, as a case study, the effectiveness of the integrated framework is validated. Study results show that the Luodexi landslide has an elevation drop of 873 m and consists of three secondary sliding bodies forming wedge-shaped failure characteristics, with the largest landslide volume of 3.6–4.0 × 106 m3. InSAR monitoring from 2016 to 2022 reveals a maximum landslide deformation rate of 40 mm/a, with cumulative displacement reaching up to 311 mm. Rainfall infiltration and snowmelt are the primary influencing factors of landslide deformation. The landslide remains relatively stable under natural conditions but becomes unstable under extreme rainfall, when the factor of safety decreases to 0.96. In the event of a complete failure, the landslide could transform into a debris flow with a runout distance of approximately 3 km that might reach the Jinsha River. Although the probability of river blockage is low, two large-scale gully accumulations require particular attention. Because it might evolve into dammed-break debris flows. The findings of this study provide valuable technical guidance for the identification and mitigation of high-altitude landslides in mountainous regions.