Previous Year Question

The Dibang, Kameng and Lohit are all tributaries of the Brahmaputra river system. The Dibang and Lohit contribute to the formation of the upper Brahmaputra, while the Kameng joins it in Assam.

Names and course of the Brahmaputra

• The Brahmaputra originates from glaciers in Tibet near the Kailash-Mansarovar region.

• In Tibet, it is known as the Yarlung Tsangpo or Tsangpo.

• It flows eastward across the Tibetan Plateau, parallel to the Himalayas.

• Near Namcha Barwa, it forms a deep gorge and turns towards the south.

• After entering Arunachal Pradesh, it is known as the Siang or Dihang.

• After being joined by the Dibang and Lohit, it becomes known as the Brahmaputra in the Assam plains.

• In Bangladesh, it is called the Jamuna and subsequently joins the Padma-Meghna system.

1. Dibang River

• The Dibang originates in the high Himalayan region of Arunachal Pradesh near the Tibetan boundary.

• It flows southward through the Upper and Lower Dibang Valley districts.

• In its mountainous course, it has a steep gradient, deep valleys and rapid flow.

• After entering the plains, it divides into several channels and develops a broad river belt.

• The Dibang joins the Siang and Lohit systems and contributes to the formation of the principal Brahmaputra channel.

• The Dibang Valley is known for Mishmi tribal areas and the rich biodiversity of the Eastern Himalayas.

• Therefore, the Dibang is a tributary of the Brahmaputra.

2. Kameng River

• The Kameng originates in the Himalayan region near the Gorichen mountain massif in the Tawang region of Arunachal Pradesh.

• It flows through the West Kameng and East Kameng regions.

• It is known as the Kameng in Arunachal Pradesh.

• After entering the Assam plains, it is known as the Jia Bharali.

• It joins the Brahmaputra near Tezpur.

• The Kameng is one of the important north-bank tributaries of the Brahmaputra.

• Its catchment extends from the High Himalayas and forested hills to the alluvial plains of Assam.

• Therefore, the Kameng is also a tributary of the Brahmaputra.

3. Lohit River

• The Lohit originates in the mountainous region of eastern Tibet.

• It enters Arunachal Pradesh near Kibithu.

• It then flows rapidly westward and south-westward through the Mishmi Hills.

• The Lohit Valley is characterised by deep gorges, rapid flow and a heavy sediment load.

• The famous Parshuram Kund is situated on the Lohit River.

• Near the Sadiya region, the Lohit joins the Dibang and Siang river systems.

• After this confluence, the principal river is known as the Brahmaputra in Assam.

• Therefore, the Lohit is a major tributary of the Brahmaputra.

Drainage relationship

Yarlung Tsangpo → Siang/Dihang
Siang + Dibang + Lohit → Brahmaputra
Kameng/Jia Bharali → Brahmaputra in Assam

Other important tributaries of the Brahmaputra

Tributaries from the north

• Subansiri

• Kameng or Jia Bharali

• Manas

• Sankosh

Tributaries from the south

• Burhi Dihing

• Disang

• Dikhow

• Dhansiri

• Kopili

The northern tributaries generally carry larger quantities of Himalayan water and coarse sediments. The southern tributaries originate from the Naga, Meghalaya and Karbi hill regions.