Maarg Manthan · Topic 15.4

Brahmaputra River System

Geography › Drainage Systems of India · Topic 15.4

The Brahmaputra rises from the Chemayungdung glacier in the Kailas range of Tibet, flows east for about 1,800 km as the Tsangpo, takes a U-turn around Namcha Barwa, enters India as the Siang or Dihang, becomes the Brahmaputra at Sadiya, and crosses Assam as a braided river up to 16 km wide before entering Bangladesh as the Jamuna. It is about 2,900 km long, floods Assam every year, and is a focus of upstream dam plans in Tibet.

5 min read · UPSC Prelims · Geography · Drainage Systems of India

At a Glance

Length About 2,900 km; about 916 km in India
Source Chemayungdung glacier, Kailas range
Names Tsangpo, Siang or Dihang, Brahmaputra, Jamuna
Special Majuli, a large river island
Hazard Annual floods and erosion in Assam
Exam link UPSC Prelims, Geography: Drainage Systems of India

Where Does It Fit?

This is the fourth topic of the macro on the drainage systems of India. The previous topic described the Ganga, and this one covers the Brahmaputra, which joins it in Bangladesh. The next topic describes the east-flowing rivers of the Peninsula. Previous topic: Ganga River System. Next topic: Peninsular Drainage and East-Flowing Rivers.

What Is the Course of the Brahmaputra?

Stage	Name	Features
Tibet	Tsangpo (the purifier); Yarlung Zangbo in China	Rises near the sources of the Indus and Sutlej, at about 5,150 m; flows east for about 1,800 km in the trough between the Great Himalaya and the Kailas range, at a very high altitude but with a gentle slope, with a navigable stretch of several hundred kilometres; tributaries include the Raga Tsangpo and the Nyang
Namcha Barwa bend	Tsangpo	Takes a sharp U-turn around Namcha Barwa (7,756 m), the eastern syntaxial bend, and cuts through the Great Himalaya in a very deep gorge, as in Himalayan Ranges – Shiwaliks, Lesser, Greater and Trans-Himalaya
Arunachal Pradesh	Siang or Dihang	Enters India and emerges from the hills near Pasighat; joined by the Dibang and the Lohit near Sadiya
Assam	Brahmaputra	Flows west across the Assam valley as a wide braided stream up to about 16 km wide at Dibrugarh; forms islands, of which Majuli is the best known; navigable for about 1,384 km from the mouth to Dibrugarh
Bangladesh	Jamuna, then Padma, then Meghna	Enters near Dhubri, flows south as the Jamuna, joins the Ganga at Goalundo to form the Padma, and meets the Meghna before the sea

The northern or left-bank tributaries in the Assam valley include the Subansiri, Kameng, Manas, Dhansiri and Sankosh; the Tista, which once flowed into the Ganga but shifted east to the Brahmaputra after the floods of 1787, joins in Bangladesh. The Dibang and Lohit join from the north-east. The southern tributaries, such as the Burhi Dihing and Kopili, are shorter.

Why Is the Brahmaputra a River of Sorrow and Strength?

Floods and erosion: the Brahmaputra carries an enormous amount of water and silt. The monsoon rainfall in the Himalayan foothills is among the heaviest in India, the channel is braided, and the banks are weak, so floods in Assam are annual and the river erodes its banks and islands. Majuli, once much larger, has lost a large part of its area to erosion. Majuli is known as the largest river island in the world and became a district in 2016.
Transport and bridges: National Waterway 2 runs from Dhubri to Sadiya. The Bogibeel Bridge near Dibrugarh, opened in 2018, is a rail-and-road bridge, and the Dhola–Sadiya bridge opened in 2017.
Hydropower: the Brahmaputra basin holds a large share of India’s hydropower potential, mostly in Arunachal Pradesh, but projects face seismic, flood and displacement concerns, as in Earthquakes – Causes, Focus and Richter Scale.
Fertility and biodiversity: Kaziranga and Manas lie on the plain of the river, and the Ganges river dolphin lives in it.

What Is the Medog Dam Debate?

China started building a huge hydropower project on the lower Yarlung Tsangpo, near the Great Bend at Medog in Tibet, with a groundbreaking in July 2025. The planned capacity is about 60 gigawatts, and the estimated cost is about 1.2 trillion yuan, which would make it much larger than the Three Gorges Dam. Downstream states and Bangladesh are concerned about the effects on flow, sediment and flood warnings, and about the risk of building in a region of high seismic activity at the meeting of the plates. India has asked for transparency and data-sharing. India has proposed the Siang Upper Multipurpose Project in Arunachal Pradesh, of about 11,000 MW, which would store water and act as a buffer, but local Adi communities oppose it because it would submerge many villages, and its approval and construction status should be checked against current reports. China is not a party to a water-sharing treaty with India, and cooperation is limited to hydrological data sharing arrangements.

As an analytical point, the Brahmaputra shows the difficulties of an upstream-downstream relationship without a treaty. The river carries a very large volume of water, but it is hard to measure and little used, so India needs flood forecasting, embankment and erosion management in Assam, and a diplomatic framework with China and Bangladesh, as in Ganga River System.

Why Is This Topic Important?

Facts Names and tributaries asked
Hazard Assam floods and erosion
Geopolitics Upstream dams

What Came Next?

The next topic describes the peninsular rivers that flow to the Bay of Bengal. Next topic: Peninsular Drainage and East-Flowing Rivers.

Key People and Terms

Tsangpo Tibetan name of the Brahmaputra
Dihang Name in Arunachal Pradesh
Braided river Channel splitting around bars
Majuli River island in Assam
Jamuna Brahmaputra in Bangladesh
Namcha Barwa Peak at the eastern syntaxial bend

Exam Corner

Points to Remember

The river is called Tsangpo in Tibet and Jamuna in Bangladesh.
Namcha Barwa marks the U-turn.
Dibang, Lohit and Siang join near Sadiya.
Majuli is a river island.
Tista shifted to the Brahmaputra in 1787.

Do Not Confuse With

Brahmaputra and Jamuna Assam name versus Bangladesh name
Jamuna and Yamuna Brahmaputra in Bangladesh versus a tributary of the Ganga
Padma and Meghna Ganga-Brahmaputra stream versus the combined estuary

Memory Hook

Tsangpo east, Namcha Barwa bends, Siang drops, Brahmaputra braids, Jamuna carries it on.

Mains Angle

Questions ask about floods and the dam debate. These points add depth.

Nature Braided and silt-laden
Risk Floods and erosion
Diplomacy Upstream dams

A Question You May Face

An original practice question, not a past paper question.

“Discuss the characteristics of the Brahmaputra and the issues arising from China’s dam projects on it.”

How to Answer

Course Tibet to Bangladesh.
Character Braided, flood-prone.
Projects Medog and Siang.
Response Data, forecasting, dialogue.

GS Relevance

Prelims: names in Tibet, India and Bangladesh, tributaries, Majuli, bridges, floods. GS Paper 1: drainage; GS Paper 2: Panchsheel agreement 1954 Asylum Dalai Lama…">India-China relations and water; GS Paper 3: floods.

Frequently Asked Questions

Where does the Brahmaputra rise?

The Brahmaputra rises from the Chemayungdung glacier in the Kailas range in Tibet, at an elevation of about 5,150 metres, close to the sources of the Indus and Sutlej. It is called the Tsangpo in Tibet, flows east for about 1,800 kilometres, and then enters India through a deep gorge.

What are the different names of the Brahmaputra?

The river is called Tsangpo or Yarlung Zangbo in Tibet and China, Siang or Dihang in Arunachal Pradesh, Brahmaputra in Assam after the confluence near Sadiya, Jamuna in Bangladesh, and then Padma after meeting the Ganga, and Meghna after meeting the Meghna river.

Why is the Brahmaputra braided?

The Brahmaputra carries a very high load of silt and has a gentle gradient in the Assam valley. It deposits sediment in the channel, which divides the flow into several channels around sandbars and islands, and these shift frequently, causing erosion of banks and floods.

What is Majuli?

Majuli is a large river island in the Brahmaputra in Assam, regarded as the largest river island in the world. It is a centre of Assamese Vaishnavite culture and became a district in 2016, but has lost a large area to river erosion over the years.

What is the Medog hydropower project?

The Medog project is a planned hydropower complex of about 60 gigawatts on the lower Yarlung Tsangpo at the Great Bend in Tibet, on which China started construction in July 2025. India and Bangladesh are concerned about its effects on river flow, sediment, flood risk and seismic safety.

PYQ Practice — Statement Analysis

1 The Brahmaputra is known as the Tsangpo in Tibet.

True

It flows east along the Himalaya.

2 The Brahmaputra makes a U-turn around Nanga Parbat.

False

It turns around Namcha Barwa.

3 Majuli is a river island in the Brahmaputra.