Nearly 300,000 Nepalese Residents Face Extreme Flood Risk from Glacial Lakes
A recent study estimates that about 294,000 people live in zones of extreme flood danger in Nepal, a figure that could rise without stronger land-use planning and early-warning systems.
Researchers have calculated that roughly 294,000 people reside in areas of extreme flood risk downstream of Nepal’s high-mountain basins, where climate-induced instability of rock and ice is increasing the number of glacial lakes. The analysis, published in Scientific Reports, identified 108,000 individuals living downstream of glacial lakes that could suddenly release large volumes of water.
The study was conducted by mapping rivers that originate in Nepal’s trans-border regions and isolating zones within 50 kilometres of glacial lakes or river headwaters. Areas that would be inundated by a 50-metre rise in water level were then highlighted as high-risk zones.
"For Nepal, it shows that there’s a lot of development going on very close to the river channel in these potentially hazardous zones," said Scott Watson, a senior research fellow at the University of Leeds who studies glacial lakes.
Watson added that the recent disaster on the main trade route between Nepal and the Tibetan Plateau underscores the need for improved early-warning systems and stricter land-use zoning. The August event, triggered by a rock and ice avalanche from Langtang Lirung, caused a debris flow that traveled about 120 miles, resulting in at least 1,455 deaths and leaving 5,285 people missing.
If no additional measures are taken, the number of people exposed to flood hazards is expected to increase, according to the researchers.