Brahmaputra River System: Geography and Significance for UPSC SSC

Origin and Course

The Brahmaputra River originates from the Chemayungdung Glacier, located near Mount Kailash in the Kailash Range of the Himalayas. This region is in southwestern Tibet, China. In Tibet, the river is known as Yarlung Tsangpo. It flows eastward for about 1,100 kilometers through a dry and flat region. The river then takes a great bend near Namcha Barwa peak (7,782 meters) and enters India. It enters India in Arunachal Pradesh, where it is called Siang. The total length of the Brahmaputra is approximately 2,900 kilometers, making it one of the longest rivers in Asia. Its basin covers parts of Tibet, India, Bangladesh, and Bhutan. The river's journey through different countries gives it various names, highlighting its international character.

Entry into India

After entering Arunachal Pradesh as Siang, the river flows southwest. It is joined by two important tributaries, Dibang (or Sikang) and Lohit, near Sadiya. From this point onwards, the river is known as the Brahmaputra. The Lohit River is particularly known for its turbulent flow and the famous Dhola-Sadiya Bridge (Bhupen Hazarika Setu), which is India's longest bridge over water. The Brahmaputra then flows through the state of Assam, forming a wide, braided channel. In Assam, it receives numerous tributaries from both its north and south banks. The river's width can be several kilometers during the monsoon season, leading to significant flooding.

Major Tributaries

The Brahmaputra has several important tributaries that contribute to its large volume of water. Key left-bank tributaries include Burhi Dihing, Dhansiri (South), and Kopili. The Burhi Dihing originates in the Patkai hills and flows through Assam. Dhansiri (South) rises in the Naga Hills. Kopili is the largest south bank tributary of the Brahmaputra in Assam. Important right-bank tributaries are Subansiri, Kameng (or Jia Bhareli), Manas, and Sankosh. Subansiri is known as the 'Gold River' and is the largest tributary of the Brahmaputra in Assam. Kameng originates in the Tawang district of Arunachal Pradesh. Manas flows through Bhutan and Assam, known for the Manas National Park. Sankosh forms part of the border between Assam and West Bengal. These tributaries significantly increase the river's discharge, especially during the monsoon.

Course in Bangladesh

After flowing through Assam, the Brahmaputra enters Bangladesh near Dhubri. In Bangladesh, it is known as Jamuna. The Jamuna flows southwards for about 240 kilometers. It then joins the Ganga River, which is known as Padma in Bangladesh. Further downstream, the combined stream of Padma and Jamuna meets the Meghna River. The Meghna is formed by the confluence of several rivers, including the Barak River in India. The final combined stream, known as Meghna, flows into the Bay of Bengal. This deltaic region is one of the largest and most fertile deltas in the world, supporting a vast population. The confluence of these mighty rivers creates a complex and dynamic riverine landscape.

Significance and Challenges

The Brahmaputra River System holds immense significance for the region. It is a major source of water for irrigation, navigation, and hydropower generation. The river supports a rich biodiversity, including the endangered Gangetic Dolphin. However, the river also poses significant challenges. It is notorious for its annual floods, especially during the monsoon season, which cause widespread devastation in Assam and Bangladesh. Erosion of river banks is another major problem, leading to loss of land and displacement of communities. Siltation is also high, reducing the river's carrying capacity. International cooperation among the riparian countries (China, India, Bangladesh, Bhutan) is crucial for effective management of the river's resources and mitigation of its challenges. The river's potential for inland waterways is also being explored.

Important Keywords Explained

Chemayungdung Glacierplace

This glacier, located in the Kailash Range of the Himalayas in southwestern Tibet, is the primary source of the Brahmaputra River. Its melting waters feed the river, which then flows eastward as the Yarlung Tsangpo before entering India.

Namcha Barwaplace

A prominent peak in the Himalayas (7,782 meters) located in Tibet. The Brahmaputra River (Yarlung Tsangpo) takes a sharp U-turn around this mountain, marking its entry point into the Indian subcontinent through Arunachal Pradesh.

Majuliplace

Majuli is a large river island in the Brahmaputra River, located in Assam, India. It was once the world's largest river island, though its size has significantly reduced due to erosion. It is a major cultural and religious center.

Dhola-Sadiya Bridgeplace

Also known as the Bhupen Hazarika Setu, this is India's longest bridge over water, spanning 9.15 kilometers. It connects Dhola and Sadiya in Assam over the Lohit River, a major tributary of the Brahmaputra.

Additional Facts & Context

• Brahmaputra is one of the few male-named rivers in India.
• The river's average annual discharge is about 19,800 cubic meters per second.
• It forms the world's largest riverine island, Majuli, in Assam.
• The Brahmaputra basin covers an area of approximately 580,000 square kilometers.
• The river is navigable for about 1,290 kilometers within India.