Hundreds of Thousands Face Growing Flood Threat from Himalayan Glacial Lakes

Scientists have calculated that approximately 294,000 people reside in areas of extreme flood risk downstream of Nepal's high-altitude river basins, with about 108,000 of them directly downstream of potentially unstable glacial lakes. The research, appearing in Scientific Reports, was motivated by the August Bhote Koshi avalanche and debris flow that caused at least 1,455 deaths and left thousands unaccounted for. Findings show that tourism, trade routes and hydropower projects have spurred construction close to river channels, increasing exposure.

Researchers used a mapping method that isolates zones within 50 km of glacial lakes and models flood scenarios with water rises of 50 meters. Experts stress the need for improved early-warning systems, stricter zoning, and prioritised flood-hazard mapping to protect vulnerable communities.