Abstract
Catastrophic hyper-concentrated flow during the glacial lake outburst flood (GLOFs) and its far-reaching consequences on life, property and infrastructure are the foremost concern throughout the high mountain areas. The present investigation focuses on a potentially dangerous moraine-dammed proglacial lake in the Bhilangna Valley, central Himalaya, India, which has been expanding at an alarming rate during the last two decades. This lake has expanded from ~0.15 to ~0.35 km2 during 1999–2020 at the cost of loss in the associated glacier area by ~0.21 km2 during the same time period. We have tried to understand the possible trigger and simulated the worst-case outburst scenario and its impact on the settlements and infrastructure in the downstream valley. Two breaching scenarios: (1) overtopping and (2) piping which may be caused by the ice calving into the lake or through avalanches, have been generated, and a maximum possible discharge amount of ~4377 cumec has been estimated considering the lake depth as 30 m. The discharge can inundate an area of ~19 km2 along the river channel with a mean water depth of ~38 m and an average velocity of ~16 m/s. The MODIS-based land surface temperature analysis from 2002 to 2020 suggests that ~19% of the total area of the Bhilangna Basin has biennial surface temperature <0°C, indicating possible permafrost zone. Both the temperature analysis and the surface features surrounding the lake suggest the region to be dominated by permafrost.
Original language | English |
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Article number | 184 |
Number of pages | 17 |
Journal | Journal of Earth System Science |
Volume | 131 |
Issue number | 3 |
Early online date | 23 Aug 2022 |
DOIs | |
Publication status | Published - Sept 2022 |
Bibliographical note
Funding Information:We dedicate this study to late Dr P K Champati Ray, Group Head, Geosciences & Disaster Management Studies Group, Indian Institute of Remote Sensing, ISRO, Dehradun. SNA is thankful to Director BSIP for constant support and motivation.
Data Availability Statement
Supplementary material pertaining to this article is available on the Journal of Earth System Science website (http://www.ias.ac.in/Journals/Journal_of_Earth_System_Science)Keywords
- central Himalaya
- Glacial lake
- risk assessment
- worst-case scenario