New Ways to Measure Himalayan Snow Could Help Warn of Future Disasters

The Himalayas contain nearly 90,000 glaciers that sustain 10 major river systems relied on by India, Pakistan, China, Afghanistan, Nepal and Bhutan, but scientists still do not know precisely how much water the mountains currently provide or how that will change — a gap that new measurement techniques are beginning to close, according to a glaciologist writing for the British Antarctic Survey.

In August 2026, a flash flood caused by a collapsed glacier washed away villages, bridges and roads on both sides of the Tibet–Nepal border, killing more than 1,000 people. A British Antarctic Survey team that had sensors 10 kilometers from the site found that enhanced melting during a spell of unusually warm weather may have introduced water into the glacier's crevasses, weakening the connections between ice and rock.

Studies project that roughly half of the glacier ice in the Himalayas — equivalent to about 2 billion Olympic swimming pools — could melt by the end of this century, enough to raise sea level by more than 1 centimeter, though considerable uncertainty remains because there are not enough measurements of snowfall and ice across the region's difficult terrain. A recent study by the author and colleagues found a new way to measure mountain snowfall that dramatically reduces measurement errors, addressing a long-standing problem that has caused mountain water resources to be underestimated for years.

Other recent efforts include a regional study that measured the water stored in some of Nepal's glaciers using instruments mounted on a helicopter, and the use of radar interferometry, which combines radio waves to detect fast-moving mountain slopes at risk of collapsing. Combining such techniques could help predict where snowfall is concentrated, how much water it will contribute, and which areas are at risk, feeding into early-warning systems.

One example of what such systems can achieve is the evacuation of the Swiss village of Blatten in 2025, where hundreds of people were moved out before a large section of a glacier broke off, after authorities identified at-risk areas and shared hazard maps based on continuous monitoring. Nepal's Koshi basin already has a community-based flood warning system, though it is limited in its ability to warn of cascading disasters like the one on the Tibet-Nepal border.