New Delhi, Feb 09: A glacier break, that caused in Uttarakhand's Chamoli on Sunday, is suspected to have caused flash floods. In October, 2020, the National Disaster Management Authority (NDMA), which is headed by PM Narendra Modi, had issued detailed guidelines on how to reduce and deal with disasters caused by what is scientifically called Glacial Lake Outburst Floods (GLOFs).
When a glacier melts, the water in glacial lakes accumulates behind loose, natural "glacial/moraine dams" made of ice, sand, pebbles and ice residue. A GLOF refers to the flooding that occurs when the water dammed by a glacier or a moraine is released suddenly.
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Unlike earthen dams, the weak structure of the moraine dam can be seen leading to the abrupt failure of the dam on top of the glacial lake, which holds a massive water content. A failure of the dam has the potential of releasing millions of cubic metres of water in a short period, causing catastrophic flooding downstream.
While some work on identification of such lakes has been done by CWC, other aspects are still a work in progress: a robust early warning system, and a broad framework for infrastructure development, construction and excavation in vulnerable zones.
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The NDMA, in its guidelines said, "In contrast to other countries, there are no uniform codes for excavation, construction and grading codes in India. Restricting constructions and development in GLOF/LLOF prone areas is a very efficient means to reduce risks at no cost."
The guidelines say construction of any habitation should be prohibited in the high hazard zone. "Existing buildings are to be relocated to a safer nearby region and all the resources for the relocation have to be managed by Central/State governments. New infrastructures in the medium hazard zone have to be accompanied by specific protection measures."