Application of Persistent Scatterer Interferometry to monitor land motion along radar line of sight in landslide-prone areas of Himachal Pradesh, India

Landslides in mountainous regions are often triggered by vertical land movements induced by tectonics or seismic activities, emphasizing the importance of monitoring such motions for early intervention. This study investigates the impact of vertical land motion on landslide-prone districts in Himachal Pradesh, India. We employ Persistent Scatterer InSAR (PS-InSAR) technology to analyse vertical land motion in the region. Utilizing a dataset spanning six years (2017–2023), we provide precise measurements of land movements with millimetre-level accuracy. Our analysis reveals a range of deformation velocities, from −10 mm/year to +5 mm/year, with observed uplift of less than 31 mm and subsidence of up to 60 mm in the study area. These movements are attributed to prolonged wet conditions, illegal land mining, and ecological vulnerability. The findings underscore the necessity of continuous monitoring to mitigate landslide risks in mountainous regions, highlighting the efficacy of PS-InSAR technology in assessing such hazards.