Precipitation dynamics and slope stability in the urban hills of baluwakhani, gangtok

Abstract Rapid urban growth and unplanned construction in fragile mountain ecosystems have significantly heightened geomorphic risks. This study evaluates the impact of rainfall variability on slope stability in Baluwakhani, a densely populated residential Municipal ward of Gangtok Municipal Corporation, Gangtok Sikkim. Spanning an area of approximately 0.4 square kilometers on a steep hillside, Baluwakhani serves as a dynamic case study for human-environment interaction under climatic pressure. Utilizing a mixed-methods approach, household surveys were systematically conducted across diverse slope positions (ridge, mid-slope, and near-valley) to document localized historical instability events—such as structural wall cracks, minor soil slips, and subsidence alongside community risk perceptions and existing drainage conditions. This primary field data was correlated with a 10-year climatological dataset (2014–2024) obtained from the India Meteorological Department (IMD) to bridge the gap between regional meteorological triggers and household-level vulnerability. The findings highlight how intense population pressure, the modification of natural slopes, and infrastructural constraints compound rainfall-induced instability. Ultimately, this research identifies key anthropogenic factors, assesses the efficacy of household-level structural adaptations like retaining walls, and provides actionable recommendations to enhance urban drainage resilience and sustainable slope management in high-risk Himalayan settlements.