Study finds nearly 300,000 residents in Nepal’s Himalayan flood zones
A new analysis estimates that about 300,000 people in the Nepalese Himalayas live in areas exposed to flooding, with over 100,000 located downstream of glacial lakes. Between 2016 and 2023, built-up land at risk in Nepal and its river catchments grew by 46%. The authors warn that retreating glaciers, expanding lakes, thawing permafrost, and continued valley development are raising hazard exposure.
The analysis covers Nepal and river basins that flow into it. Using a terrain-based measure of building elevation relative to nearby streams, plus satellite records of structures, researchers tracked flood exposure from 2016 to 2023. They found that built-up areas in harm’s way rose by 46%.
Almost 300,000 residents are estimated to live in flood-prone Himalayan zones, with more than 100,000 below glacial lakes. These lakes can burst suddenly. Meanwhile, shrinking glaciers, thawing permafrost, and expanding valley settlements and infrastructure continue to increase the number of people and assets potentially affected.
The study may sharpen awareness among Himalayan communities, local planners, and disaster agencies about where flood exposure is concentrated. Residents, travelers, hydropower workers, and traders using valley corridors could face greater disruption if development continues in flood-prone areas. Better exposure maps and early warning systems may help authorities prioritize preparedness, land-use decisions, and infrastructure safeguards, though risk also depends on building quality, warning access, and other local factors.