Gangtok, 21 April (IPR) : The scientific team from Sikkim State Climate Change Cell (NMSHE)under State Council of Science and Technology recently developed a glacial lake volume and area(VA) Equation based on the scientific interventions carried out at South Lhonak Lake. The scientific team who are involved in the development of this Empirical equation are Shri. R.K. Sharma (Scientist B), Shri. Pranay Pradhan (Scientist B), Shri. N.P. Sharma (Asst. Scientific Officer), who have contributed 4 years of intensive field as well as multi temporal satellite databased studies to come up with the Volume area equation, in order to calculate the storage volume of other potentially dangerous glacial lakes in the Sikkim Himalaya and Indian Himalaya as a whole. The principle investigator to this project was Shri. D.G. Shrestha, Additional Director, Department of Science, Technology and Climate Change.
The scientific paper entitled “Remote sensing and in situ-based assessment of rapidly growing South Lhonak glacial lake in eastern Himalaya, India” has recently published in peer-reviewed reputed Journal ‘Natural Hazards’, Springer Publication, Journal of the International Society for the Prevention and Mitigation of Natural Hazards (DOI 10.1007/s11069-018-3305-0). The paper deals with the remote sensing as well as a field-based assessment of rapidly growing South Lhonak glacial lake in Sikkim Himalaya and recommends sustainable adaptation and mitigations measures to tackle the GLOFs in the region.
For the first time in Indian Himalaya, the scientific team led by Shri. R.K. Sharma (Scientist B) developed an empirical equation for the volume-area relationship in South Lhonak Lake. Based on the measured volume and vector layer of all the lake boundaries derived from the multi-temporal satellite images during different periods,the scientific team proposed an empirical relation between lake volume and area of South Lhonak lake, as under;
(R2 = 0.99)
whereV is the volume, A is the area, and R2 is the coefficient of determination.
The Equation is tested with the other moraine-dammed glacial lakes volume measured in Himalaya and the equation corresponds very well with the measured volume of glacial lakes.
Salient features and implications of our Glacial lake Volume –Area (VA) equation
This is the first glacial lake volume and area(VA) equation developed for moraine-dammed glacial lakes in Indian Himalaya
The computed lake volume from the equation correspond well with measured volume of the glacial lakes of Himalaya
The equation gives a more accurate estimation of volume for the glacial lakes in the Himalaya with smaller error compared to the equation developed by the predecessor like Huggel and others (2004), and Yao and others (2012).
The present volume-area relationship can be extensively used to calculate the storage volume of similar moraine-dammed glacial lakes in Sikkim Himalaya and Indian Himalaya as a whole.
It is difficult and expensive to carry out the field based assessment in every glacial lake in Himalaya which are expanding due to melting glaciers, due to the limits imposed by high altitude, remote locations, harsh environment and risk of life due to snow avalanches, debris flows etc. Therefore by utilizing the Empirical equation, one can calculate the volume of glacial lakes and prioritize the important glacial lakes, which are potentially dangerous for GLOFs. This enables to plan for specific adaptation and mitigation to reduce the impacts of outburst floods.
Further, the present findings can help policy and decision makers to formulate the effective strategies and policies in reducing disaster risks andmitigating plan to minimize the threat of GLOFs in Sikkim Himalaya.
The Department of Science, Technology and Climate Change, GoS had nominated Shri. R.K Sharma for the Indo Swiss capacity Building programme on Himalayan Glaciology in the year 2013. Further he was qualified to the advanced glaciological Programme (Level II) in Jawaharlal Nehru University during 2013. He was among the 15 candidates from India and only from Sikkim, who have completed the Advance Glaciological Training with a field training at Chhota Shigri Glacier, HP. Further, he was actively involved in the scientific assessment of probability of Glacial lake outburst floods (GLOFs) in South Lhonak lake in Sikkim in the year 2014 and actively worked for the mitigation measures at South Lhonak lake during 2016. Furthermore he is also working in Glacier dynamics of East Rathong glacier, the source of river Rangit in West Sikkim. His contribution to the study of glaciers and glacial lakes in Sikkim was well documented in the photo story “Living on the Thin Ice” published by Indian Himalayan Climate Change Adaptation Programme (IHCAP) during 2016(https://ihcap.exposure.co/living-on-thin-ice). In addition, another scientific team member, Shri Pranay Pradhan is also a trained glaciologist who has completed field training at Hamtah Glacier, H.P. from Geological Survey of India, Lucknow. Both Scientists are actively involved in the study of glaciers and glacial lakes in Sikkim since from last 8 years.