Nearly 300,000 People Live in Flood-Prone Areas of the Nepalese Himalayas, New Research Finds

Nearly 300,000 people are estimated to live in areas vulnerable to flooding across the Nepalese Himalayas, including more than 100,000 people living downstream of glacial lakes, according to new research published in The Conversation. The study highlights the growing threat posed by climate change, as rising temperatures accelerate glacier melting, expand glacial lakes and thaw mountain permafrost. These changes increase the risk of floods, landslides and other natural hazards in steep Himalayan valleys. The dangers were highlighted by a devastating disaster on August 26, when a rock-and-ice avalanche triggered a massive flood in Nepal. Researchers found that between 2016 and 2023, built-up areas potentially exposed to flooding in Nepal and the catchment areas of rivers draining into the country increased by 46 per cent.

The research also highlights how expanding settlements and infrastructure are increasing the number of people exposed to potential disasters. Glacial lakes are a particular concern because their natural barriers can suddenly fail, releasing large volumes of water into downstream valleys. Researchers used satellite-derived building data and elevation measurements to identify areas potentially exposed to flooding. They stressed that living in a flood-prone area does not necessarily mean a disaster will occur, as the actual risk also depends on building quality, early-warning systems, preparedness and evacuation plans. The findings underline the importance of better flood-risk mapping and careful land-use planning to ensure that new homes, roads and other infrastructure are not developed without considering future hazards. Combining climate research with effective disaster preparedness could help protect vulnerable Himalayan communities as environmental risks continue to grow.