India, Sept. 5 -- The eastern Himalayan state of Sikkim has identified 40 high-hazard glacial lakes, with 16 of them classified as being at the highest risk of catastrophic outbursts that could threaten downstream settlements.

The data is significant as it comes against the backdrop of the recent flash flood in Nepal, triggered by a glacial collapse near the Nepal-Tibet border on August 26 that left a trail of destruction with hundreds of people dead and scores missing.

Though the catastrophe was not linked to a Glacial Lake Outburst Flood (GLOF), the flash flood has highlighted a broader transformation across the Himalayas as glaciers retreat, new lakes are forming in their place, while existing ones are expanding.

Glacial lakes are f...