Geophysical and geotechnical characterization of Lower Sudhan Gali Landslide (LSGL), Bagh Azad Jammu & Kashmir

Abstract

The evolution of the steep unstable slopes is influenced by landslides as a major geomorphological feature in the Kashmir region. The NW-SE–oriented landslide has affected the village of Birpani and the main Sudhan Gali Road. The Lower Sudhan Gali (LSG) landslide was studied using a combined use of ground-based remote sensing (Electrical Resistivity Tomography (ERT)) and space-borne remote sensing (Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR)) measurements, geotechnical and field surveys. PSInSAR data highlighted the parts of the landslide that are currently active as well as the immediate surrounding area experiencing uplift and subsidence phenomenon. ERT imaging has delineated the geometry and subsurface structural features of the LSGL. Geotechnical results indicated that the landslide material had a low to medium plasticity index, with a higher clay fraction that may have reduced its shear strength. Finally, the characteristics of this mass movement were observed during the geological field by analyzing the geomorphological features and the lithological units. The interplay among rainfall and close proximity of a major fault may have contributed to the landslide kinematics. The results provided important on- and near-ground surface information for effective planning interventions that can help with hazard mitigation.

Keywords

• Landslide
• ERT
• remote sensing
• geotechnical
• geohazard