Landslide detection in Kinnaur Valley, NW India using PS-InSAR technique

Remote sensing techniques, such as Interferometric Synthetic Aperture Radar (InSAR), have the potential to document and monitor surface deformation up to a millimetre scale especially in areas where ground monitoring is not feasible. The InSAR technique has been used to isolate and map some current and potential landslide areas in Kinnaur region of the Satluj Valley in Himachal Pradesh. The fragile ecosystem of Kinnaur has been challenged by the shifting climatic pattern and immense anthropogenic pressure associated with burgeoning hydroelectric projects, leading to destructive landslides of epic proportions. Three recent landslides that occurred at Ribba and Pangi villages of the Satluj River Valley and the Batseri landslide in the Sangla Valley were studied and potential landslide areas along the Satluj Valley were mapped with Sentinel-1 multi-baseline interferograms using data acquired between 2016 and 2021. The analysis suggests significant changes in velocities (±11 mm/y) where the subsidence rate ranges from −6 to −11 mm/y with a cumulative displacement of ±45 mm/y. Our study highlights the potential locations for future landslides and provides an early warning landslide map to support future disaster prevention in highly deformed regions.