Geotechnical and Geophysical Characterization of the Aklesal Dablyang Landslide: Implications for Slope Stability

Landslides constitute one of the principal perils in Nepal, particularly within its hilly and mountainous terrains, where a confluence of geological fragility and climatic extremities engenders precarious landscapes. Such hazards precipitate considerable loss of life and property. This investigation centers on the Aklesal Dablyang landslide in Baglung district, a potent menace to local infrastructure, agricultural domains, and human lives. By deploying a synthesis of geotechnical (laboratory-based soil analysis) and geophysical (Electrical Resistivity Tomography (ERT)) methodologies, the intrinsic properties of the soil and rock substrata within the landslide precinct were meticulously examined. The findings reveal that the landslide comprises predominantly loose colluvial deposits with elevated moisture levels, resulting in reduced shear strength and heightened failure susceptibility. The study accentuates the pivotal influence of hydrological phenomena such as surface runoff and groundwater seepage in aggravating slope destabilization. These results underscore the exigency for efficacious risk mitigation strategies to diminish landslide impacts on vulnerable communities. The Aklesal Dablyang landslide exemplifies the intricate interplay of geological and hydrological dynamics within Nepal’s complex topographical context. This research delineates the geotechnical and geophysical determinants of slope stability, highlighting the prevalence of loose colluvial deposits exacerbated by substantial moisture content, which attenuates shear strength and heightens vulnerability to mass movement. ERT analyses divulged a stratigraphy dominated by clayey sand interspersed with cobbles and boulders, which exhibit pronounced susceptibility to mass displacement during intense monsoonal precipitation—a phenomenon exacerbated by climate change. Anthropogenic interventions, including deficient drainage systems and substandard construction methodologies, further destabilize slopes by escalating pore-water pressure and diminishing soil cohesion. The study accentuates the imperative for integrative risk management paradigms, encompassing resilient engineering solutions, hydrological controls, and community collaboration, to bolster resilience against such geo-hazards.