Brahmaputra

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Ganges-Brahmaputra-Meghna basins

Brahmaputra (ब्रह्मपुत्र) is a trans-boundary river in Asia. It is also one of the major rivers of Asia that cuts through 4 countries: China, India, Bhutan and Bangladesh.

Variants of name

Origin

It originates in the Angsi glacier, located on the northern side of the Himalayas in Burang County of Tibet as the Yarlung Tsangpo River[2].

Course

After its origin it flows across southern Tibet to break through the Himalayas in great gorges (including the Yarlung Tsangpo Grand Canyon) and into Arunachal Pradesh (India), where it is known as Dihang or Siang.[3] It flows southwest through the Assam Valley as Brahmaputra and south through Bangladesh as the Jamuna (not to be mistaken with Yamuna of India). In the vast Ganges Delta, it merges with the Padma River, the popular name of the river Ganges in Bangladesh, and finally the Meghna and from here it is known as Meghna River before emptying into the Bay of Bengal.[4]

About 2,900 km long, the Brahmaputra is an important river for irrigation and transportation. The average depth of the river is 124 ft and maximum depth is 380 ft. The river is prone to catastrophic flooding in spring when the Himalayan snows melt.

The river drains the Himalaya east of the Indo-Nepal border, south-central portion of the Tibetan plateau above the Ganges basin, south-eastern portion of Tibet, the Patkai-Bum hills, the northern slopes of the Meghalaya hills, the Assam plains, and the northern portion of Bangladesh. The basin, especially south of Tibet, is characterized by high levels of rainfall. Kangchenjunga (8,586 m) is the only peak above 8,000 m, hence is the highest point within the Brahmaputra basin.

The Brahmaputra's upper course was long unknown, and its identity with the Yarlung Tsangpo was only established by exploration in 1884–86. This river is often called Tsangpo-Brahmaputra river.

The lower reaches are sacred to Hindus. While most rivers on the Indian subcontinent have female names, this river has a rare male name, as it means "son of Brahma" in Sanskrit (putra means "son").[5]

The Brahmaputra River (also called as "Burlung-Buthur" by the Bodo people of Assam), called Yarlung Tsangpo in Tibetan language, originates on the Chemayungdung Glacier located on the northern side of the Himalayas in Burang County of Tibet.

From its source, the river runs for nearly 1,100 km in a generally easterly direction between the main range of the Himalayas to the south and the Kailas Range to the north. Throughout its upper course, the river is generally known as the Tsangpo (“Purifier”); it is also known by its Chinese name (Yarlung Zangbo) and by other local Tibetan names.

Tributaries

In Tibet, the Tsangpo receives a number of tributaries. The most important left-bank tributaries are the Raka Zangbo (Raka Tsangpo), which joins the river west of Xigazê (Shigatse), and the Lhasa (Kyi), which flows past the Tibetan capital of Lhasa and joins the Tsangpo at Qüxü. The Nyang Qu (Gyamda) River joins the river from the north at Zela (Tsela Dzong). On the right bank, a second river called the Nyang Qu (Nyang Chu) meets the Tsangpo at Xigazê.

After passing Pi (Pe) in Tibet, the river turns suddenly to the north and northeast and cuts a course through a succession of great narrow gorges between the mountainous massifs of Gyala Peri and Namjagbarwa (Namcha Barwa) in a series of rapids and cascades. Thereafter, the river turns south and southwest and flows through a deep gorge (the “Grand Canyon” of the Tsangpo) across the eastern extremity of the Himalayas with canyon walls that extend upward for 16,500 ft and more on each side. During that stretch, the river enters northern Arunachal Pradesh state in northeastern India, where it is known as the Dihang (or Siang) River, and turns more southerly.

The Brahmaputra enters India in the state of Arunachal Pradesh, where it is called Siang. It makes a very rapid descent from its original height in Tibet, and finally appears in the plains, where it is called Dihang. It flows for about 35 km and is joined by the Dibang River and the Lohit River at the head of the Assam Valley. Below the Lohit, the river is called Brahmaputra, enters the state of Assam, and becomes very wide—as wide as 10 km in parts of Assam. It is joined in Sonitpur by the Kameng River (or Jia Bhoreli).

The Dihang, winding out of the mountains, turns toward the southeast and descends into a low-lying basin as it enters northeastern Assam state. Just west of the town of Sadiya, the river again turns to the southwest and is joined by two mountain streams, the Lohit and the Dibang. Below that confluence, about 900 1,450 km from the Bay of Bengal, the river becomes known conventionally as the Brahmaputra (“Son of Brahma”). In Assam, the river is mighty, even in the dry season, and during the rains, its banks are more than 8 km apart. As the river follows its braided 700 km course through the valley, it receives several rapidly rushing Himalayan streams, including the Subansiri, Kameng, Bhareli, Dhansiri, Manas, Champamati, Saralbhanga, and Sankosh Rivers. The main tributaries from the hills and from the plateau to the south are the Burhi Dihing, the Disang, the Dikhu, and the Kopili.

Between Dibrugarh and Lakhimpur Districts, the river divides into two channels—the northern Kherkutia channel and the southern Brahmaputra channel. The two channels join again about 100 km downstream, forming the Majuli island, which was, until some time back, the largest river island in the world.[6] At Guwahati, near the ancient pilgrimage centre of Hajo, the Brahmaputra cuts through the rocks of the Shillong Plateau, and is at its narrowest at 1 km bank-to-bank. Because of the river's narrow width, the Battle of Saraighat was fought here in March 1671. The first combined rail/road bridge across the Brahmaputra was opened to traffic in April 1962 at Saraighat.

The environment of the Brahmaputra floodplains in Assam have been described as the Brahmaputra Valley semi-evergreen forests eco-region.

In Bangladesh, the Brahmaputra is joined by the Teesta River (or Tista), one of its largest tributaries. Below the Tista, the Brahmaputra splits into two distributary branches. The western branch, which contains the majority of the river's flow, continues due south as the Jamuna (Jomuna) to merge with the lower Ganges, called the Padma River (Pôdda). The eastern branch, formerly the larger, but now much smaller, is called the lower or old Brahmaputra (Bromhoputro). It curves southeast to join the Meghna River near Dhaka. The Padma and Meghna converge near Chandpur and flow out into the Bay of Bengal. This final part of the river is called Meghna River.

The Brahmaputra enters the plains of Bangladesh after turning south around the Garo Hills below Dhuburi, India. After flowing past Chilmari, Bangladesh, it is joined on its right bank by the Tista River and then follows a 150-mi (240-km) course due south as the Jamuna River. (South of Gaibanda, the Old Brahmaputra leaves the left bank of the main stream and flows past Jamalpur and Mymensingh to join the Meghna River at Bhairab Bazar.) Before its confluence with the Ganges, the Jamuna receives the combined waters of the Baral, Atrai, and Hurasagar Rivers on its right bank and becomes the point of departure of the large Dhaleswari River on its left bank. A tributary of the Dhaleswari, the Buriganga (“Old Ganges”), flows past Dhaka, the capital of Bangladesh, and joins the Meghna River above Munshiganj.

The Jamuna joins with the Ganges north of Goalundo Ghat, below which, as the Padma, their combined waters flow to the southeast for a distance of about 120 km. After several smaller channels branch off to feed the Ganges-Brahmaputra delta to the south, the main body of the Padma reaches its confluence with the Meghna River near Chandpur and then enters the Bay of Bengal through the Meghna estuary and lesser channels flowing through the delta. The growth of the Ganges-Brahmaputra Delta is dominated by tidal processes.

The Ganges Delta, fed by the waters of numerous rivers, including the Ganges and Brahmaputra, is 59,570 square kilometres the largest river deltas in the world.[7]

History

Early accounts give its name as Dyardanes.[8]

Tej Ram Sharma[9] writes that the Allahabad pillar inscription of Samudragupta mentions Kamarupa (कामरूप) (L. 22) as one of the frontier states which were subordinate to Samudragupta and whose emperors paid him taxes and all kinds of obeisance. Majumdar [10] identifies it with Upper Assam. Kamarupa consisted of the Western districts of the Brahmaputra valley which being the most powerful state and being the first to be approached from the western side came to denote the whole valley. [11] The area of Kamarupa was estimated by the Chinese traveller Hiuen Tsang to have been 10,000 li i.e. 1667 miles in circuit which shows that it must have comprised the whole valley of Brahmaputra. [12] Saktisangama describes [13] Kamarupa as extending from Kalesvara to the Svetagiri and from Tripura to the Nila-parvata (which is the Niladri or Nilakuta, the name of the Kamakhya hill). According to the Yogini Tantra, the kingdom of Kamarupa included the whole of the Brahmaputra valley together with Rangpur and Cochbihar. [14] The Puranas mention Pragjyotisa, identified with Kamakhya or Gauhati, as the capital of Kamarupa. [15] The Kamauli grant of Vaidyadeva mentions Kamarupa as a Mandala of the Pragjyotisa-bhukti. [16]


In the past, the course of the lower Brahmaputra was different and passed through the Jamalpur and Mymensingh districts. Some water still flows through that course, now called the Old Brahmaputra, as a distributary of the main channel.

A question about the river system in Bangladesh is when and why the Brahmaputra changed its main course, at the site of the Jamuna and the "Old Brahmaputra" fork that can be seen by comparing modern maps to historic maps before the 1800s.[17] The Brahmaputra likely flowed directly south along its present main channel for much of the time since the last glacial maximum, switching back and forth between the two courses several times throughout the Holocene.[18]

One idea about the most recent avulsion is that the change in the course of the main waters of the Brahmaputra took place suddenly in 1787, the year of the heavy flooding of the river Tista. It is, however, well known that the Tista has always been a wandering river, sometimes joining the Ganges, sometimes being shifted westwards by the superior strength of that river and forced to join the Brahmaputra.

In the middle of the 18th century, at least three fair-sized streams flowed between the Rajshahi and Dhaka Divisions, viz., the Daokoba, a branch of the Tista, the Monash or Konai, and the Salangi. The Lahajang and the Elengjany were also important rivers. In Renault's time, the Brahmaputra as a first step towards securing a more direct course to the sea by leaving the Mahdupur Jungle to the east began to send a considerable volume of water down the Jinai or Jabuna from Jamalpur into the Monash and Salangi. These rivers gradually coalesced and kept shifting to the west till they met the Daokoba, which was showing an equally rapid tendency to cut towards the east. The junction of these rivers gave the Brahmaputra a course worthy of her immense power, and the rivers to right and left silted up. In Renault's Altas they very much resemble the rivers of Jessore, which dried up after the hundred-mouthed Ganges had cut her new channel to join the Meghna at the south of the Munshiganj subdivision.

In 1809, Buchanan Hamilton wrote that the new channel between Bhawanipur and Dewanranj "was scarcely inferior to the mighty river, and threatens to sweep away the intermediate country". By 1830, the old channel had been reduced to its present insignificance. It was navigable by country boats throughout the year and by launches only during rains, but at the point as low as Jamalpur it was formidable throughout the cold weather. Similar was the position for two or three months just below Mymensingh also.

External links

References

  1. Michael Buckley (2015-03-30). "The Price of Damming Tibet's Rivers". New Delhi: New York Times. p. A25.
  2. Yang Lina (2011-08-22). "Scientists pinpoint sources of four major international rivers". Xinhua.
  3. "Yarlung Tsangpo River in China". Atmospheric Data Science Center.
  4. "Brahmaputra River Flowing Down From Himalayas Towards Bay of Bengal"
  5. Gopal, Madan (1990). K.S. Gautam, ed. India through the ages. Publication Division, Ministry of Information and Broadcasting, Government of India. p. 80.
  6. Majuli, River Island. "Largest river island". Guinness World Records.
  7. Singh, Vijay P.; Sharma, Nayan; C. Shekhar; P. Ojha (2004). The Brahmaputra Basin Water Resources. Springer. p. 113. ISBN 978-1-4020-1737-7
  8. A compendium of ancient and modern geography: for the use of Eton School By Aaron Arrowsmith, page 56
  9. Personal and geographical names in the Gupta inscriptions/Place-Names and their Suffixes, p.253-254
  10. The Vakatka-Gupta Age by R. C. Majumdar and A.S. Altekar. p. 142.
  11. The Ancient Geography of India by Alexander Cunningham. p. 500
  12. The Ancient Geography of India by Alexander Cunningham. p. 500
  13. Studies in the Geography of Ancient and Medieval India by D. C. Sircar. pp. 86-87 : Saktisangama Tantra, Book III, ch. VII, V. 10.
  14. Studies in the Geography of Ancient and Medieval India by D. C. Sircar., p. 87 : Historical Geography of Ancient India by B. C. Law. p. 226.
  15. Geographical Dictionary of Ancient and Medieval India by N. L. Dey. p. 87 ; Cities of Ancient India by B. N. Pur. pp. 85-88
  16. Epigraphia Indica. II, p. 353, LL. 48-49 ; Ethnic Settlements in Ancient India by S. B. Chaudhuri, p. 172.
  17. e.g. Rennell, 1776; Rennel, 1787
  18. Jennifer L. Pickering, Steven L. Goodbred, Meredith D. Reitz, Thomas R. Hartzog, Dhiman R. Mondal, Md. Saddam Hossain. Late Quaternary sedimentary record and Holocene channel avulsions of the Jamuna and Old Brahmaputra River valleys in the upper Bengal delta plain, Geomorphology, Available online 4 October 2013, ISSN 0169-555X

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