Majority of Himalayan glaciers melting and retreating at varying rates
Accelerated heterogeneous mass loss in Himalayan glaciers has been observed by various studies conducted by several Indian institutes and organisation..
Updated 7 Apr 2022, 5:37 am
Various studies conducted by several Indian institutes and organisations observed accelerated heterogeneous mass loss in Himalayan glaciers. The researchers observed that majority of Himalayan glaciers are observed melting and retreating at varying rates in different regions, Minister of State for Earth Sciences and Science and Technology, Dr Jitendra Singh informed the House on Wednesday.
The Geological Survey of India (GSI), the Wadia Institute of Himalayan Geology (WIHG), the National Centre for Polar and Ocean Research (NCPOR), National Institute of Hydrology(NIH), the Space Application Centre (SAC), and the Indian Institute of Science (IISc) etc have been monitoring Himalayan glaciers for various scientific studies, including glacier melting.
According to various studies, the mean retreat rate of Hindu Kush Himalayan glaciers is 14.9 ± 15.1 meter/annum (m/a); which varies from 12.7 ± 13.2 m/a in Indus, 15.5 ± 14.4 m/a in Ganga and 20.2 ± 19.7 m/a in Brahmaputra river basins, However, glaciers in the Karakoram region have shown comparatively minor length change (-1.37 ± 22.8 m/a), indicating the stable conditions, the minister mentioned in a written reply in the Lok Sabha.
The minister stated that the Ministry of Earth Sciences (MoES) through its NCPOR has been monitoring six glaciers in the Chandra basin (2437km2 area) in western Himalaya since 2013.
A state-of-the-art field research station ‘Himansh’ was established in Chandra basin and operational since 2016 for conducting field experiment and expeditions to glaciers, he said.
The rate of annual mass balance (melting) ranging from -0.3±0.06 meter water equivalent per year (m w.e.y-1) to -1.13±0.22mw.e.y-1 during 2013-2020 is observed. Similarly, a mean thinning of ~50±11 m with a mean annual mass loss of –1.09± 0.32 mw.e. a–1 was observed for the Baspa basin during 2000-2011, he pointed out.
GSI has conducted studies on melting of the glaciers by assessment of mass balance on nine glaciers and also carried out monitoring the recession/ advancement of 76 glaciers in Himalayan region. It observed that Majority of Himalayan glaciers are observed melting/ retreating at varying rates in different regions.
Meanwhile, the Department of Science and Technology (DST) has supported various R&D projects for studying Himalayan Glaciers under the National Mission for Sustaining Himalayan Ecosystem (NMSHE) and National Mission on Strategic Knowledge for Climate Change (NMSKCC).
The mass balance studies conducted for some Himalayan glaciers by the University of Kashmir, Sikkim University, IISc and the Wadia Institute of Himalayan Geology (WIHG) revealed that majority of Himalayan glaciers are melting or retreating at varying rates.
The WIHG is monitoring a few glaciers in Uttarakhand, which reveal that the Dokriani Glacier in the Bhagirathi basin is retreating at 15-20 m/a since 1995, whereas Chorabari Glacier in the Mandakini basin is retreating at 9-11 m/a during 2003-2017.
The institute is also monitoring Durung-Drung and Pensilungpa glaciers in Suru basin, Ladakh, which are retreating at 12 m/a and ~ 5.6 m/a, respectively. NIH has been conducting several studies for the assessment of runoff from melting of glaciers at catchment and basin scales across Himalaya.
The minister also mentioned that melting glaciers have significant impact on water resources of Himalayan rivers due to change in glacier basin hydrology, downstream water budget, impact on hydropower plants due to variation in discharge, flash flood and sedimentation. They also increase in risk related to glacier hazards due to enhanced number and volume of glacier lakes, accelerated flash flood and Glacial Lake Outburst Floods (GLOFs), impact on agro practices in high Himalayan region etc.
Divecha Centre for Climate Change, IISc Bangalore under the aegis of DST has investigated Satluj River basin and reported that there will be an increase in glacier melt contribution until the middle of the century and then there will be a decline. Numerous small glaciers located in the low altitude region of the Satluj basin indicate significant loss in the area till the middle of the century, creating a scarcity of water during the dry summer season.
Various Indian institutes, organizations and universities are monitoring the Himalayan glaciers using remote sensing data at large scale to assess the calamities associated with the melting. Recently, the National Disaster Management Authority (NDMA) in collaboration with the Swiss Development Corporation (SDC), prepared the Guidelines, Compendium and Summary for Policy Makers on the management of the Glacial Lake Outburst Floods (GLOFs), the minister added. (PIB)