Cryosphere - A Freshwater Ecosystem
The freshwater ecosystem discourse in India is largely focused on rivers, lakes, ponds, wetlands, aquifers, and streams. They have been a part of various conservation and restoration initiatives. However, these discourses and initiatives have turned a blind-eye to another crucial freshwater ecosystem, the Cryosphere, which lies in the Hindu Kush Himalayas and is the origin of three major river systems in North India - Ganga, Brahmaputra, and Indus. This photo story aims to introduce the various components and dynamics within the Cryosphere, its functions, and ecosystem services with a focus on the Ganga River. The story also aims to highlight the heightened vulnerability of this ecosystem due to global warming, urges for its inclusion to the freshwater ecosystem discourse, and consequent inclusion in conservation and restoration initiatives. This photo-story has emerged from the study titled ‘The Heads and Tails of Ganga’ - The Cryosphere and the Delta conducted by Prof. Vijay Paranjpye, Radhika Mulay, and Chaitrali Kulkarni funded by INTACH, Delhi. The book was launched at the India Rivers Week on 25th November, 2023.
Gomukh, Gangotri Glacier
Are you Forgetting Something? The Cryosphere!
Hello! I’m a Bharal, also known as a Himalayan blue sheep because of my grayish-blue fur!
Hello! Surprised to see me here? Well, I understand, you have not been very good observers anyway. All you have been doing is trotting around with your fancy mountaineering gear and Royal Enfield bikes. I can understand how you’ve overlooked spotting me and where I live while you are busy taking your selfies. So, today, I’ve decided to come to you, to remind you about my home which you have forgotten.
I often hear you talking about the pristine blue waters of the Sutlej River (a tributary of the Indus in Himachal Pradesh), the Bhagirathi River (a tributary of the Ganga in Uttarkashi), the Brahmaputra River in Assam, but do you know where this crystal clear water comes from? I’m sure you’ve heard of the atmosphere, the hydrosphere, and the biosphere but have you heard of the Cryosphere?
The name says it all! ‘Cryo’ in Ancient Greek is κρύος or krúos which literally translates to icy cold, chill or frost. So, in essence, the entire region that is covered in snow and ice above the 4000-5000m snowline in the majestic Hindu Kush Himalayas is the Cryosphere. It thereby refers to the glaciers, glacial wetlands and lakes, permafrost, land slopes, peaks, rocky outcrops, valleys, and gorges covered in snow and ice spanning a geographical area of 594,400 sq.km.
This region is also known as ‘The Third Pole’ - the third largest area in the world that is perpetually covered in snow and ice after the North Pole (Arctic) and South Pole (Antarctic). It contains the largest reserve of freshwater in the world outside the polar regions within a geographical area of around 4.2 million sq.km. (Bajracharya SR, 2011).
The Cryosphere in the Hindu Kush Himalayas
The Shivling peak in the Gangotri Glacier, Uttarakhand. Photo by Swanand Kulkarni
A Significant Contributor to the Hydrological Budget
This region acts as the storehouse for the millennial freshwater which regulates the flow of glacier-fed rivers in the lean seasons and along with rainfall forms the origin of ten major river basins - Indus, Ganga, Yangtze, Brahmaputra, Salween, Mekong, Irrawaddy, Amu Darya, Tarim, and Yellow River, which currently supply water to 18 countries in Asia.
Within the Indian subcontinent, the snow and ice melt from this region contributes to almost nine to ten percent of the water in the Central Ganga Basin, 19-21 percent of the Brahmaputra Basin, and 50 percent of the annual flows of the Indus (Miller et al., 2012).
Snow melt is water that melts from the annual snowfall which is part of the annual hydrological cycle. Ice melt forms the share of the stream which is part of ice stock that has accumulated over millennia and is part of the geological hydrological cycle.
The contribution of snow and ice melt becomes significant during the “lean flow” seasons, especially during the summer months, when the rainfall contribution is almost negligible. Consequently, its contribution is crucial for maintaining the minimum Environmental Flows (E-Flows), similar to the base flows released from groundwater aquifers.
The cryosphere is thus a significant contributor to the hydrological budget of the Himalayan rivers and within India supports the growing population and livelihoods in the Ganga, Indus and Brahmaputra basins in the states of Himachal Pradesh, Punjab, Haryana, Rajasthan, UT Jammu & Kashmir, Leh-Ladakh, Uttarakhand, Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Jharkhand, Bihar, Delhi, Arunachal Pradesh, Assam, Nagaland, Meghalaya, West Bengal, and Sikkim.
But you’re probably wondering how all this happens. Let me take you on a tour of the water cycle within the Cryosphere.
Water which has been stored in the form of snow and ice in the glaciers and permafrost starts to melt during the summer months making the glaciers flow. Photo by Swanand Kulkarni
Yes, not just water, glaciers also flow! Photo by Swanand Kulkarni
Close up images of glacial-flow. Photos by Swanand Kulkarni
A close-up of the glacial flow in Gangotri glacier. One can see a wave-like formation in the glacier stem formed due to periodic cooling and melting indicating the flow. Photo by Swanand Kulkarni
Why isn't the Glacier White like Ice or Snow?
Generally, one visualizes a glacier as a smooth white surface, or a river suddenly frozen in its tracks. However, in reality, this is true only in the uppermost segment for about five kms or the accumulation zone. In the middle and lower sections, however, the glacier is covered with a thin layer of grey and black loose sand, rocks, and boulders spread across the length and breadth of the glacier, except for the wide crevasses and cracks that show a bluish white colour.
As the snow and ice melt starts to flow downwards, it carries loose sand, pebbles, boulders, and dust which are called debris. This debris is the sediment and silt which is later filtered, carried off by the river flow, and deposited in the plains which makes the land fertile for agriculture.
It is because of this sediment and silt that the glaciers and water flowing looks muddy unlike the pristine white snow-clad glaciers and the crystal clear blue waters which we see in the rivers downstream.
The uppermost segment or the accumulation zone. Photo by Swanand Kulkarni
The middle and lower sections of the glacier covered in debris. Photo by Swanand Kulkarni
Path of glacier melt carrying sediment and silt from the mountain top towards the foothills. Photo by Swanand Kulkarni
Greyish-black water stream carrying sediment and silt. Photo by Rucha Ghanekar
Pro-Glacial Stream: Origin of Rivers
While glaciers move very slowly, the ice begins to melts when it comes in contact with the rock underneath due to a difference in temperatures. This melted water begins to trickle down from under the glacier eventually forming a tiny stream called a pro-glacial stream.
If you put your ear to the Gangotri glacier, you can hear a continuous flow of water running underneath. This water, a combination of snow and ice melt, emerges as a stream at Gomukh forming the origin of Bhagirathi River, a tributary of the Ganga River. Due to global warming and melting glaciers there are now two points of origin at Gomukh as can be seen in the next image.
Gomukh forming the origin of Bhagirathi River, a tributary of the Ganga River. Now there are two points of origin due to glacial melt, based on 2019 field trip. Photo by Swanand Kulkarni
Image showing flow of water underneath a sheet of ice. Photo by Swanand Kulkarni
Sometimes before flowing downstream, water is caught in the low-lying areas and depressions forming glacial lakes. Photo by Swanand Kulkarni
Image of Roopkund, a glacial lake in Uttarakhand. Left: the flow of ice and snow into the lake. Right: the development of infrastructure around the lake. Photos by Anagha Athavale
Water from these pro-glacial streams and glacial lakes slowly begins to seep down forming small rivulets or streams. Photos by Swanand Kulkarni
The entire landscape showing the flow of glaciers that ultimately form a water stream. Photo by Swanand Kulkarni
Streams from different glaciers form tributaries. Photo by Swanand Kulkarni
Glacial streams and tributaries create various unique geological formations. Photo by Vijay Paranjpye
These tributaries ultimately join each other to form the main river stem. Confluence of Bhagirathi and Alaknanda tributaries at Devprayag from where the main river stem is known as Ganga. Photo by Anagha Athavale
Along with silt and sediments, waters from the Cryosphere also contribute to the minerals and nutrients in the river flow which gives every river a unique characteristic. In this case, it is the different coloured waters as shown in the previous image of the confluence of Bhagirathi and Alaknanda Rivers at Devprayag.
With climate change, due to rapid glacial melt, this millennial water store is becoming part of the annual water cycle but this is not understood due to a lack of knowledge about this region and awareness. This also has implications on water quantity, quality, biodiversity, and livelihood in the upstream as well as downstream river regimes. Acknowledging the importance of Cryosphere in the freshwater ecosystem discourse and including these regions in the data repository is an important step towards their protection and preservation.
Now that you have understood how the Cryosphere is the source of some India’s most important rivers, we hope you will remember us the next time you visit the Himalayas.
References
Bajracharya SR, S. B. (2011). The Status of Glaciers in the Hindu Kush–Himalayan Region. International Centre for Integrated Mountain Development (ICIMOD), 33(1), 114–115.
Miller, J., Imeerzeel, W. ., & Rees, G. (2012). Climate Change Impacts on Glacier Hydrology and River Discharge in the Hindu Kush – Himalayas, A Synthesis of the Scientific Basis. Mountain Research and Development., 32, 461–467.
Remember My Home the Next Time You Visit the Himalayas!
About Radhika Mulay
With a Master's in Water Science, Policy and Management from the University of Oxford, UK, Radhika has worked as an environmental researcher on an international academic-activist research program ACKNOWL-EJ at Kalpavriksh, Pune. From 2020-22 she worked as a Senior Researcher on research projects related to ‘Mahabaleshwar Panchgani Eco-Sensitive Zone (MPESZ)’ and was one of the authors of the book: ‘The Heads and Tails of Ganga River’ – the Cryosphere and the Delta at Gomukh Trust, Pune. Currently, she is based at the Centre for Water Research and the Living Waters Museum, IISER-Pune and is exploring her interests in the field of water research and the arts.
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