Brahmaputra River System: North and South Bank Tributaries of Brahmaputra UPSC

Brahmaputra River System

As per the latest news, the Brahmaputra River System is prone to flood. It has observed hundreds of floods in the past, but recently, it became a major concern in the news as a tragic boat mishap happened in September 2021. In this incident, several people lost their lives.

Brahmaputra River System UPSC

Below, you will learn about the important aspects of the Brahmaputra River System, including its features, tributaries, and importance.

Features of Brahmaputra River System

In a country where most rivers have female names, the Brahmaputra River stands out due to its rare male name. The Brahmaputra is a Sanskrit term for "son of Brahma." But that is not the reason behind this river assuming significance. Here are the vital features of the Brahmaputra River System that make it important for India and other countries:

• Brahmaputra River Origin: The Brahmaputra River traces its origin to Tibet. It originates in the Chemayungdung Glacier at an elevation of 5300m in the Kailash Mountain range in the Himalayas.
• It is identified as the Yarlung Tsangpo River in Tibet. It enters India through Arunachal Pradesh and continues its journey through the Assam Valley and Bangladesh, where it is known as Jamuna. Finally, it flows into the Bay of Bengal.
• As per new findings, the length of the Brahmaputra river is 3969 km. It is the 15th longest river on earth.
• Its drainage area is 712,035 km2, which is among the largest in India (1,4). The catchment area is 194413 km2.
• The average discharge of the Brahmaputra River System is about 700,000 cubic feet per second.
• This river has an average depth of 30 m, while its maximum depth is 135 m.
• The river is prone to calamitous flooding and riverbank erosion in spring due to snow melting in the Himalayas.
• The Saraighat Bridge was the first bridge built on the Brahmaputra in 1962 that supports both rail and road traffic.
• At 9.15 km, the DholaSadiya Bridge spanning the river's Lohit tributary is India's longest bridge over water.
• It is a braided river. Its Majuli island is the largest river island in the world.
• The Brahmaputra river, specifically in the portions in Assam, receives the highest rainfall pattern, resulting in riverbank erosion and annual flooding.
• The river is highly susceptible to avulsion and channel migration. It tends to abandon its river channel and form a new channel rapidly.
• It is among the few rivers on earth that exhibit the phenomenon of a tidal bore.
• UNESCO has recognized Majuli (district of Assam), an island, as the world's largest and one of the oldest inhabited riverine islands.
• About 55.48% of the river basin is covered with forests.
• Geologically, the Brahmaputra is the youngest among the major rivers on earth.

Tributaries of Brahmaputra

The Brahmaputra is joined by several tributaries on its north and south banks. These tributaries are rain-fed, and few among them foam up with rain that results in extreme floods.

North Bank Tributaries of Brahmaputra

The major tributaries on the north bank of Brahmaputra river are as follows:

• Aie
• Saralbhanga
• Champamati
• Pagladiya
• Puthimari
• Jaidhal
• Sankosh
• Manas
• Dhansiri
• Kameng
• Siang
• Subansiri

The characteristics of the north bank tributaries of Brahmaputra include:

• They generally experience flashy floods.
• They carry a serious slit charge and have coarse sandy beds, pebbles, and boulders.
• They possess steep slopes.

South Bank Tributaries of Brahmaputra

Some prominent features of the south bank tributaries of Brahmaputra include the following:

• These tributaries have a low silt charge compared to the heavy silt charge in the north bank tributaries.
• Have flatter grades and deep winding channels from the foothills.

The south bank tributaries of the Brahmaputra River System are as follows-

• Bhogdoi
• Kulsi
• Jinjiran
• Krishnai
• Dudhnai
• Digaru
• Kopili
• Dhansiri
• Dikhow
• Debang
• Buridehing
• Noa Dehing

The south bank tributaries have deep meandering channels and flatter grades as compared to the north bank tributaries. Also, unlike north bank tributaries, they have a low slit charge. The tributaries flowing via northern West Bengal join the mainstream of the Brahmaputra. These are,

• Jaldhaka
• Torsa
• Raidak-I
• Raidak-II
• Sankosh
• Tista

Significance of Brahmaputra River System

About 130 million people live on the Brahmaputra delta and 600000 on the riverine islands. These people depend on annual river flooding for agricultural and marine farming. China revealed in April 2010 that they were constructing the Zangmu Dam in Tibet on the Brahmaputra. This can have a big impact on the river's flow in India. It also increases the risk of artificial floods due to mishandling the water flow.

The mighty Brahmaputra river system ensures water security, supports irrigation, and serves as a vital inland waterway in the northeast. But heavy flooding and massive erosion of river banks are its main problems. India needs to implement concrete plans for river drainage to control floods and prevent bank erosion.

Dams built on Brahmaputra River System

In states where the Brahmaputra river passes by, dams are built to produce electricity, provide drinking water to the local people, etc. Check the dams built on Brahmaputra River System across different Indian states through the following table:

Ganga Brahmaputra Delta

The Ganga Brahmaputra is formed by the combined water of several river systems, mainly of Brahmaputra and Ganga, and is the largest river delta in the world. Also, it is one of the most fertile lands in the world. The area is a high-risk zone for flood, and despite that, more than 100 million people live on the delta, and it is believed that the delta supports the lives of more than 300 million people. The delta has not only fertile lands but is also home to wildlife like Bengal Tiger, Elephant, Ganga river Dolphin, birds like kingfisher, eagle, woodpecker, and various others.

Brahmaputra River System UPSC

Going through these notes on the Brahmaputra River System UPSC is important for all aspirants preparing for the upcoming IAS exam. These are prepared from the exam point of view, keeping in mind the latest news, important tributaries of Brahmaputra, etc., which might be asked in the Prelims and Mains examination.