APSC Answer Writing (Daily) based on Assam Tribune – 31/10/2026

Model answer

The recent sudden discharge of 7.4 million cubic metres of water from Bhutan’s Shintaphu Lake highlights the acute transboundary Glacial Lake Outburst Flood (GLOF) threats facing downstream Indian states like Assam.

Underlying Causes of Himalayan GLOFs

• Accelerated Glacial Retreat: Rising global temperatures are causing Himalayan glaciers to melt at unprecedented rates, forming rapidly expanding proglacial lakes at high altitudes [IPCC AR6 Report].
• Fragility of Natural Barriers: These lakes are dangerously held back by loose, unconsolidated deposits of rocks, sand, and glacial debris (moraines) that lack structural integrity.
• Formation of Artificial Dams: Debris flows frequently block source rivers, creating highly unstable artificial lakes prone to sudden bursting.
• Seismic & Meteorological Triggers: The region’s susceptibility to earthquakes, combined with heavy inflows from extreme weather or ice avalanches, can instantly overtop natural barriers.

Downstream Impact Dynamics on Assam

• Riverine Inundation: Floodwaters from Bhutan’s Mo river enter the Punatsangchu basin, flowing into India as the Sankosh river, directly threatening plain districts.
• Human Displacement: Sudden surges necessitate mass emergency evacuations, disrupting livelihoods in highly vulnerable revenue circles like Golokganj and Agomoni in Dhubri.
• Infrastructure Destruction: High-velocity surges carrying massive volumes of lethal sediment, rocks, and debris physically obliterate cross-border riverbanks, bridges, and roads.

Critical Evaluation of Assam’s Preparedness

Way Forward

• Proactive Engineering: Support bilateral initiatives where Bhutanese authorities can safely and artificially drain vulnerable glacial lakes to reduce hydrostatic pressure.
• Transboundary Sensor Grid: Establish an integrated, automated telemetry network between Bhutan and India along the Sankosh and Mo rivers for instantaneous alerts [NDMA Guidelines].
• Vulnerability Fortification: Conduct comprehensive structural assessments and fortification of settlements and bridges located along the immediate course of the Sankosh river.

Transitioning from reactive emergency evacuations to proactive mitigation requires institutionalizing a joint Bhutan-India hydrometeorological framework and building climate-resilient infrastructure in vulnerable border districts.