Assessing the potential landslide risk identification in the northern section of CPEC route Pakistan based on Multi-Temporal InSAR approaches

Landslides are the most frequent geoenvironmental natural hazards in hilly regions, owing to broken rock masses and slope instability. Every year, landslides occur along the Karakorum highway in the northern section of the China–Pakistan Economic Corridor, involving complex geological action and causing significant damages and fatalities. To mitigate landslide hazard risks and a better understanding of landslide occurrence in steep mountainous regions, a comprehensive and precise analysis of slow-moving landslides is necessary. To address this challenge, a Multi-Temporal (MT), Interferometry Synthetic Aperture Radar (InSAR) approach using Small Baseline Subsets and Interferometric Point Target Analysis techniques was utilized to extract ground deformation rates. A total of 121 multitrack synthetic aperture radar images from Sentinel-1A were acquired from 2021 to 2023, enabling the detection and monitoring of ground displacement over time. Eight active slope movements were successfully identified by calculating the differences in deformation, indicating a significant deformation rate within the trust fault lines and regional geological formations. The research findings reveal that the regional geological structure, including lithology and fault lines, significantly increase the deformation rate. These identified landslide hazard areas range from 1.47 km 2 to 14.88 km 2 , with an annual average rate of line of sight surface displacement estimated between −4.13 to −16.07 cm/yr. The MT-InSAR analysis demonstrates that fault lines and geology play significant role in surface deformation, providing valuable insights into the deformation induced by regional tectonic activities.