3 min readAug 31, 2026 06:00 AM IST First published on: Aug 31, 2026 at 06:00 AM ISTThe Himalayan mountain system is the ecological mainstay of large parts of the Indian Subcontinent. It is the wellspring of rivers and shapes the monsoon. Its forests support biodiversity, and the region is home to several pilgrimage centres. However, the range has become increasingly fragile in recent years. The mounting toll of the flash floods that struck Nepal last week after a glacier collapse near the country’s border with China sent torrents of water down the Bhote Koshi River is a grim reminder of the region’s precarity. It underscores how a disturbance in higher altitudes can swiftly become a downstream catastrophe.Several studies, including IPCC reports, have documented the retreat of glaciers in the rapidly warming Himalaya. The meltwater accumulates in glacial lakes, many of which are held back by unstable dams of boulders. These lakes can suddenly burst, sending enormous volumes of water and debris down narrow valleys. Landslides, avalanches and erratic rainfall can trigger cascading events. The Nepal disaster appears to have involved an ice-and-rock avalanche. It is not an isolated incident. A glacial lake outburst in Nepal’s Everest region led to massive flooding two years ago. A 2021 study by scientists from IIT Roorkee, IISc Bengaluru, University of Dayton, University of Graz, and the Universities of Zurich and Geneva flagged instability around South Lhonak Lake in Sikkim. The warning went largely unheeded — the lake burst two years later, killing at least 50 people.AdvertisementThe expansion of roads, hydropower schemes and tourism facilities in the valleys has added another layer of risk. Such projects are necessary for livelihoods, energy security and connectivity. But infrastructure development must factor in the idiosyncrasies of mountain ecology. Environmental assessments must account for the cumulative risks from infrastructure projects, while construction standards must reflect the requirements of an unstable landscape. Glaciers need continuous monitoring, with information shared across borders because Himalayan rivers and hazards do not respect political boundaries. Some efforts are underway. India is accelerating early-warning systems for the region’s lakes, while Nepal and China share information on Himalayan ecology. But last week’s disaster is a stark reminder of how much more needs to be done. The Bhote Koshi’s warning system, designed to track the gradual movement of glacial water, could not detect the sudden surge of debris. The experience of Switzerland, where advance monitoring and evacuation helped limit casualties after a glacier collapse destroyed much of the Blatten region in 2025, offers useful lessons. The geology of the Alps and Himalaya is, of course, vastly different. Even then, the salience of sharing expertise across mountainous regions cannot be understated. These imperatives must now be integrated into technology transfer programmes under climate pacts.