Reducing imminent risks due to glacial lake outburst flood (GLOF) in Puna Tsang Chu basin
National Centre for Hydrology and Meteorology
Lay summary
The Puna Tsang Chhu basin, originating from the highly glaciated northwestern region of Bhutan, is one of the most vulnerable river systems in the country to Glacial Lake Outburst Floods (GLOFs). Accelerated glacier melt has led to the expansion of supra-glacial ponds and the formation of large moraine-dammed glacial lakes. The basin contains several potentially dangerous glacial lakes which pose significant risks to downstream communities, critical infrastructure, and hydropower projects. The country has already experienced two GLOF incidents from Thorthormi Lake in the past five years, demonstrating the urgency of proactive intervention.
Given that over 70% of Bhutan’s settlements lie along river valleys, GLOF risk represents a major national hazard. While Bhutan has made substantial progress in glacial lake monitoring and risk assessment, critical gaps remain in real-time observation, early warning, and institutional capacity for field-based monitoring and rapid response.
The project aims to reduce imminent risks and enhance resilience of downstream communities and ecosystems in the Puna Tsang Chhu basin through improved glacial lake monitoring, hazard assessment, and early warning capabilities.
Details
| Regional focus | High-altitude |
| Location | Bhutan, Puna Tsang Chu basin |
| Funded amount | 226,000 CHF |
| Project dates | 1st March 2026 – 31st March 2028 |
| Category | International Collaboration |