By Priya Ranganathan | Illustration by Krithika Sampath
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High in the Great Himalayas, enormous slabs of ice give rise to gushing water. These rivers of ice – known as glaciers – feed some of India’s largest and most important rivers with melting water. Millions of people depend upon the waters that flow from these glaciers to support their livelihoods and for drinking water. These great rivers – the Ganga, the Yamuna, the Brahmaputra, the Teesta, and the Indus, among others – water the land and create fertile belts where crops grow and civilizations thrive.
Glaciers were relatively unknown until 1840-1850, when one glacier known as Pindari Glacier in Uttar Pradesh, became a popular site as it was easy to approach. Today, one of the best-known (and indeed, the largest) glaciers in India is the Gangotri Glacier, the birthplace of the holy river Ganga and a holy pilgrimage site for Hindus. Glaciers are spread across the high Himalayan ranges, with the largest number occurring in Jammu and Kashmir. These slow-moving icy rivers form over centuries from accumulated snow and pressure. A combination of pressure (upper snow layers pressing down on lower layers to form ice) and gravitational pull causes glaciers to move slowly.
As glaciers move, they sweep up everything that they encounter in their paths, creating a wide variety of unique glacial features – cirques, moraines, glacial lakes, snow bridges, and glacial valleys! They are the engineers of the snow peaks, and as they move downhill, their ice begins to melt and rivers are born.
Let us take a look at some of the glaciers of the Himalayas and the many rivers that are born from their wombs.
Nestled amidst the peaks that straddle India and Tibet lies the peaceful pilgrim town of Uttarkashi. This town is famous for its nearness to two important glaciers – Gangotri and Yamunotri. Gangotri is by far the larger, measuring nearly 30 km long and 2-4 km wide! It holds over 27 cubic km of water, which rushes out of the mouth of the glacier, which is known as Gomukh (“mouth of the cow”) due to its interesting shape. From Gomukh flows the Bhagirathi, the headstream of the Ganga. She tumbles down past villages and meadows of flowers, finally rushing into the plains near Hrishikesh and Haridwar. The Ganga flows for 2,525 km from Gangotri to the Sundarbans Delta, which straddles West Bengal and Bangladesh. It is joined along its path by the languid Yamuna, who also has humble beginnings in the Himalayas. Yamunotri is the glacial source of the Yamuna, located on the slopes of Bandarpooch Peak in the Garhwal Himalayas. Below the glacier is a shrine to the river goddess, frequented by pilgrims in the warmer months. The Yamuna flows along her separate course, joining the Ganga at Prayagraj (Allahabad). The place where the rivers join is known as the Triveni Sangam because it is said that the Saraswati River (which no longer flows above the ground) also meets the Ganga and Yamuna here.
Let us fly away to the Eastern Himalayas, on the slopes of the world’s third-highest mountain (and India’s highest mountain) – Kanchenjunga – in Sikkim. Here lies the Zemu Glacier, the largest glacier in the Eastern Himalaya, which drains the eastern side of the mountain. Zemu is one of the glaciers that feeds the magnificent Teesta River, which joins the Jamuna River in Bangladesh after traversing Sikkim, West Bengal, and eventually, Bangladesh! Many of the mighty Himalayan rivers meet the Bay of Bengal at the Sundarbans delta, perhaps the world’s largest delta and an ever-shifting geological feature. As freshwater flows change over time, the mouth of the delta changes its shape too, sometimes widening and sometimes becoming a narrower V-shape. Here, the land is always changing, thanks to the power of water!
The longest glacier in the Indian Himalayas is the 78-metre-long Siachen Glacier, located in Jammu and Kashmir. The Siachen gives rise to the Nubra River, which joins the mighty Indus. The Indus is one of the few major Himalayan rivers that drains into the Arabian Sea; most rivers make their winding way to the eastern coastline of India. The Indus begins in Tibet and takes a convoluted route through Ladakh and into Pakistan. It then bends sharply and passes a vast gorge near Nanga Parbat, entering the fertile plains of Punjab and Sindh in Pakistan. The word “Punjab” means “land of five rivers,” referring to five major rivers that drain the province and join the Indus – the Chenab, the Ravi, the Sutlej, the Beas, and the Jhelum.
The Himalayas are a treasure trove of natural resources, with nearly 10 major river systems originating here and over three million springs, feeding 64% of irrigated land in the Himalayan region. Glaciers have shaped the distribution and supply of water in northern India, providing a year-round supply of freshwater that nourishes crops and provides for over 500 million people!
However, as temperatures warm with the addition of greenhouse gases in the atmosphere, glaciers in the Himalayas have been melting at increasingly alarming rates. The World Meteorological Organization estimates that temperatures in the Himalayas have experienced a rise of 0.4 degrees Celsius higher than the global average, spelling danger for our glaciers (Maurer et al. 2019). With warmer temperatures, the self-purifying ability of Himalayan rivers would also reduce and the chances of seasonal drought across India’s rice and bread baskets would have grave impacts on agriculture and food supply.
If our glaciers continue to melt, what will become of the rivers that rely upon them for longevity? We must act now, so that we don’t face a future where our glaciers disappear and the great rivers that flow across our land slowly run dry.
To learn more about Gangotri, the source of the Ganges, you can watch this short documentary by BBC Earth titled “The Source of the Ganges” HERE
About the Author:
Priya Ranganathan is a wetland ecologist and geologist by training who works in the wild Western Ghats. When she isn’t out wading through swamp forests, she can be found scribbling away in her notebook or practicing Bharatanatyam. Check out her website ‘On Life and Wildlife.’
About the Artist:
Krithika Sampath is a self taught artist who experiments with different mediums to illustrate her love for all things nature.