New Delhi: Himalayan glaciers are retreating at “varying rates” and melting of glaciers can’t be prevented or slowed down, Union Minister of Earth Sciences, Kiren Rijiju, told the Rajya Sabha in a written reply today.
The Indian Space Research Organization’s (ISRO’s) Space Application Centre (SAC) has mapped 5234 glaciers of the Himalayan-Karakoram (H-K) region using primarily IRS LISS III data which indicated a varied loss in glacier area in the region.
The Geological Survey of India (GSI) and various Institutes/Universities under the projects funded by the Department of Science and Technology (DST) too have conducted mass balance studies on a number of glaciers and found that the majority of Himalayan glaciers are melting/ retreating at varying rates in different regions.
Rijiju said the glacier inventory prepared by the National Centre for Polar and Ocean Research (NCPOR) for the Chandra basin (2437 km2 area) in the western Himalayas shows that it has lost about 6% of its glacial area during the last 20 years and 2.4-meter water equivalent (m w.e.) to 9 m w.e. ice mass during 2013-2021. The glaciers in the Bhaga basin lost huge ice mass in the range of 6 m w.e. to 9 m.w.e. during 2008-2021. The annual rate of retreat of Chandra basin glaciers varied from 13 to 33 meters/year during the last decade.
The Ministry of Earth Sciences (MoES) through its autonomous institute NCPOR, has been monitoring six glaciers in the Chandra basin since 2013. A state-of-the-art field research station ‘Himansh’ was established in the Chandra basin and operational since 2016 for conducting field experiments and expeditions to glaciers.
Besides, DST’s Wadia Institute of Himalayan Geology (WIHG) observed that glaciers in the Garhwal Himalaya show significant heterogeneities in glacier thinning and surface flow velocity patterns. The observations show an overall retreat of glaciers with variable rates of melting and retreat based on different facets like topography (elevation, aspect and slope), climate (temperature and precipitation) and debris cover. The observed retreats are 15-20 m/year for the Dokriani Glacier in Bhagirathi basin, 9-11 m/year Chorabari Glacier in Mandakini basin, ~12 m/year at Durung-Drung and ~ 5.6 m/year at Pensilungpa glaciers in Suru basin.
WIHG has been pursuing cryospheric research on different aspects that include glacier dynamics, hydrology and hazards using both satellite data and ground-based observations, Rijiju said.
The Earth Sciences Minister said 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 stable conditions.
He said the recession or melting of glaciers is mainly caused by global warming and climate change. Therefore, the rate of melting of glaciers can’t be prevented or slowed down, unless all the factors responsible for global warming and climate change can be controlled.
In view of the above, though various Indian institutes, organizations and universities are monitoring the Himalayan glaciers using both field and remotely sensed data to comprehensively understand the nature of their response, none have reported any suggestions related to preserving the Himalayan glaciers.
Incidentally, the volume of flow at Bhojwasa downstream of Gaumukh recorded by the National Institute of Hydrology (NIH) since 2000 does not show much variation. The NIH has been monitoring the hydrological and hydro–meteorological data at Bhojwasa for all these years. It is also monitoring two glaciers namely Phuche and Khadung in Ladakh Himalayas since 2010.
The Minister informed the Rajya Sabha that several Indian institutes, universities and organizations funded by various government agencies monitor the Himalayan glaciers for various scientific studies including glacier melting and they have reported accelerated heterogeneous mass loss in Himalayan glaciers.
Around 90 research personnel including scientists, faculties as well as research scholars in different academic and research institutions across the country are engaged for the purpose of conducting research work on Himalayan glaciers for the last three years, he said.
– global bihari bureau
