Catastrophic ice-debris flow in the Rishiganga River, Chamoli, Uttarakhand (India)

Geomatics, Natural Hazards & Risk

S. Nawaz Ali¹  Rupendra Singh²  Rajesh Kumar³  Syed Umer Latief⁴  Arun Kumar Tripathi⁵  Vijendra Kumar Pandey⁵  Dakshina Tamang⁶  Suresh Chand Rai⁷  Vijay Kumar Soni⁸  Ramesh P. Singh⁹ 

[1] Birbal Sahni Institute of Palaeosciences;CPS, School of Social Sciences, Jawaharlal Nehru University;Department of Environmental Science, School of Earth Sciences, Central University of Rajasthan;Department of Geography, Amar Singh College;Department of Geography, Kirori Mal College, University of Delhi;Department of Geography, Sikkim University;Department of Geography, University of Delhi;Environment Monitoring and Research Center (EMRC), India Meteorological Department, Ministry of Earth Sciences, Mausam Bhawan;School of Life and Environmental Sciences, Schmid College of Science and Technology, Chapman University, One University Drive;

关键词: catastrophic flood;    rockslide;    ice-avalanche;    climatic variability;    garhwal himalaya;   

DOI  :  10.1080/19475705.2021.2023661

来源: DOAJ

【 摘 要 】

A catastrophic flood occurred on 7 February 2021 around 10:30 AM (local time) in the Rishiganga River, which has been attributed to a rockslide in the upper reach of the Raunthi River. The Resourcesat 2 LISS IV (8 February 2021) and CNES Airbus satellite imagery (9 February 2021) clearly show the location of displaced materials. The solar radiation observed was higher than normal by 10% and 25% on 6 and 7 February 2021, respectively, however, the temperature shows up to 34% changes. These conditions are responsible for the sudden change in instability in glacier blocks causing deadly rock-ice slides that led to the collapse of the hanging glacier as a wedge failure. The displaced materials mixed with ice, snow, and debris caused catastrophic floods downstream within no time that destroyed critical infrastructure and killed human lives. The hydrodynamic modelling (HEC-RAS software) shows mean flow velocity up to 22.4 ± 8.6 m/s with an average depth of 16.3 ± 6.5 m that caused deadly devastation in the source region and along the rivers due to the flow of water in the valley.

【 授权许可】

Unknown