Comprehensive evaluation and prediction of potential long-runout landslide in Songrong, Tibetan Plateau: insights from remote sensing interpretation, SBAS-InSAR, and Massflow numerical simulation

This study aims to address the challenge of early identification and understanding of the mechanisms that trigger potential long-runout landslides, which are often concealed at high altitudes and sudden in occurrence in the Tibetan Plateau. Through the integration of remote sensing interpretation, SBAS-InSAR, and Massflow numerical simulation, this study presents a comprehensive evaluation and prediction of the potential long-runout landslide in Songrong, Derong County, China. The results reveal that Sentinel-1 ascending data are more appropriate for monitoring the deformation characteristics of the Songrong landslide, which has a maximum deformation rate of − 43 mm/a (ascending) and − 8 mm/a (descending) between January 2016 and February 2022. The landslide scarp at the rear edge measures up to 71 m, and the tensile crack extends 110 m with a maximum width of 6 m. After a heavy rainfall event on July 15, 2018, the deformation rate significantly increased to − 233.26 mm/a within 5 months. The landslide accumulation area shows a creep-accelerated creep-stable-creep deformation pattern matching the rainfall cycle. The study concludes that the Songrong landslide has the potential for long-altitude initiation risk under the effects of heavy rainfall and earthquakes. Massflow numerical simulation estimates the whole process from long-altitude initiation to remote accumulation to be approximately 200 s, with an estimated accumulation volume of 1.05 × 10⁶ m³, which could potentially dam the Dingqu River. In light of these findings, it is recommended to strengthen remote sensing investigations, InSAR deformation monitoring, and field investigations of potential long-runout landslides on the Tibetan Plateau to establish measures for their early identification and prevention of associated hazards.