Assessment of potential present and future glacial lake outburst flood hazard in the Hunza valley: A case study of Shisper and Mochowar glacier

Hemant Singh; Divyesh Varade; Maximillian Van Wyk de Vries; Kirtan Adhikari; Manish Rawat; Shubham Awasthi; Deepak Rawat

doi:10.1016/j.scitotenv.2023.161717

Assessment of potential present and future glacial lake outburst flood hazard in the Hunza valley: A case study of Shisper and Mochowar glacier

Sci Total Environ. 2023 Apr 10:868:161717. doi: 10.1016/j.scitotenv.2023.161717. Epub 2023 Jan 20.

Authors

Hemant Singh¹, Divyesh Varade², Maximillian Van Wyk de Vries³, Kirtan Adhikari⁴, Manish Rawat⁵, Shubham Awasthi⁶, Deepak Rawat⁷

Affiliations

¹ Department of Civil Engineering, Indian Institute of Technology Jammu, India. Electronic address: hemant.singh@iitjammu.ac.in.
² Department of Civil Engineering, Indian Institute of Technology Jammu, India. Electronic address: divyesh.varade@iitjammu.ac.in.
³ School of Environmental Sciences, University of Liverpool, Liverpool L3 5DA, UK; School of Geography and the Environment, University of Oxford, United Kingdom. Electronic address: vanwy048@umn.edu.
⁴ College of Science and Technology, Royal University of Bhutan, Bhutan. Electronic address: adhikari.cst@rub.edu.bt.
⁵ Water Resource Development and Management, Indian Institute of Technology Roorkee, India. Electronic address: manish.wr@sric.iitr.ac.in.
⁶ Centre for Excellence in Disaster Management, Indian Institute of Technology Roorkee, India. Electronic address: sawasthi@dm.iitr.ac.in.
⁷ Centre for Excellence in Disaster Management, Indian Institute of Technology Roorkee, India. Electronic address: drawat1@dm.iitr.ac.in.

PMID: 36682568
DOI: 10.1016/j.scitotenv.2023.161717

Abstract

In Himalayas, new glacial lake formation and expansion of existing glacial lakes have occurred as a consequence of the increasing temperature and glacier recession. These lakes have the potential to release catastrophic volumes of water and trigger a glacial lake outburst flood (GLOF). GLOFs can cause devastating downstream impacts including loss of lives, damage to infrastructure, and economic loss. The risk associated with GLOFs is evident in the case of the Mochowar and the Shisper glaciers of the Hunza valley in the Karakoram ranges. The present study is divided in two parts: 1) investigation of the recent GLOF event from the Shisper glacier ice-dammed lake on 7th May 2022. 2) identification of an overdeepening site for future lake formation at the Mochowar glacier and its future GLOF susceptibility; We used the Himalayan Glacier Thickness Mapper (HIGTHIM) to calculate the thickness of Mochowar glacier and identify an overdeepening site at its terminus. This site could host a glacial lake of area 0.22 km² and a mean depth of 58.97 m that can release a potential flood volume leading to cascading effects with the Shisper ice-dammed lake that further increases the GLOF susceptibility. The GLOF susceptibility of this future lake was determined to be high based on a multi-criterion decision analysis. The recent GLOF event of 7th May 2022 occurred from the Shisper glacier ice-dammed lake. We applied a 2D hydrodynamic model for investigating this GLOF episode and estimated a release volume of 6.23 × 10⁶ m³, with a modelled peak discharge of approximately 1505 m³ s^-1.

Keywords: GLOF; Glacier ice thickness glacier velocity; Ice-dammed Lake.