GLOF Disaster in Sikkim: A Case Study of South Lhonak Lake

Abstract

The Himalayan region is highly tectonically active, rendering Sikkim an ecologically and geologically fragile zone. Exacerbated by climate change, disasters like landslides, earthquakes, cloudbursts, and Glacial Lake Outburst Floods (GLOFs) have increased in frequency. Situated in seismic Zone IV, Sikkim’s steep slopes and complex geological structures further elevate its vulnerability, causing severe socio-economic and ecological losses. This study aims to address these escalating threats, focusing on emerging catastrophic phenomena like GLOFs and evaluating how geospatial technologies can minimize risk. Methodologically, the paper examines recent disaster events as case studies—most notably the catastrophic Sikkim disaster of October 3, 2023—to analyze the compound effects of simultaneous heavy rainfall, seismic activity, and landslides. The findings reveal that these multi-hazard events trigger devastating, far-reaching consequences. Structurally, they cause massive destruction to critical infrastructure (roads, bridges, and dams), cutting off essential services to large areas. Furthermore, these events have transboundary consequences that severely impact low-lying downstream areas in Bangladesh, while simultaneously degrading the fragile local ecosystem and halting regional development projects. In conclusion, natural disasters in Sikkim pose a continuous threat to human life, economic stability, and environmental sustainability. To effectively manage these hazards within hostile and inaccessible mountainous terrains, the integration of Remote Sensing (RS) and Geographic Information System (GIS) technologies is crucial. Incorporating these geospatial tools into formal planning frameworks significantly enhances regional disaster preparedness, optimizes emergency response strategies, and minimizes future vulnerabilities and damages.