Integrated Geomorphological and Remote Sensing-Based Recognition of Deep-Seated Gravitational Slope Deformations Around the Budhigandaki Hydropower Reservoir, Central Nepal Himalaya
DOI:
https://doi.org/10.64862/Keywords:
Deep-Seated Gravitational Slope Deformation (DGSD), Budhigandaki hydropower reservoir, Central Nepal himalaya, Geomorphological mapping, InSAR, Reservoir rim stabilityAbstract
Deep-Seated Gravitational Slope Deformations (DGSDs) are slow-moving, large-scale slope failures that pose significant hazards in mountainous terrains, particularly along reservoir rims. This study integrates geomorphological mapping, Sentinel-1 InSAR time-series, and field verification to identify and characterize DGSDs around the Budhigandaki Hydropower Reservoir in the Central Nepal Himalaya. High-resolution (5 m) DEM derivatives enabled identification of morphological indicators such as antiscarps, double ridges, sagging slopes, and bulging toes. InSAR analysis quantified line-of-sight displacements, revealing active or potentially reactivating DGSD zones. Field surveys provided lithological and structural context. DGSDs are concentrated along steep slopes (>30°), where lithological contrasts and structural discontinuities (foliation, joints, shear zones, faults) guide deep-seated movements. InSAR measurements show slow deformation rates (3–5 mm/year). This integrated approach provides a robust framework for DGSD recognition, slope-hazard assessment, and reservoir rim monitoring, supporting long-term stability of hydropower infrastructure.
References
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