Brahmaputra River

Brahmaputra River UPSC

The Brahmaputra River, one of the major rivers of South Asia, is renowned for its immense length, cultural significance, and ecological importance. Originating in the Tibetan Plateau, the river traverses through China, India, and Bangladesh, enriching the lands and supporting millions of people and diverse ecosystems along its course.

Origin and Course

The Brahmaputra originates from the Angsi Glacier (Kailash Range) in the Himalayas, located in Tibet, China, at an elevation of approximately 5,150 meters. In its upper reaches, the river is known as the Yarlung Tsangpo. 

Yarlung Tsangpo flows eastward for about 1,700 kilometers through the arid Tibetan Plateau, carving one of the deepest gorges in the world near Namcha Barwa, where the river takes a U-turn with an extraordinary vertical drop of 25,154 feet before entering India in the state of Arunachal Pradesh. 

In Arunachal Pradesh, it takes the name Siang or Dihang and descends into the fertile plains of Assam. At that point, the Siang contributes about 30% of the water of the Brahmaputra. Other large tributaries join the Brahmaputra along the Assam valley in India, so that it carries eight times more water when it exits the country to Bangladesh than when the Siang enters Arunachal Pradesh.

Just west of Sadiya (Assam), the Siang or Dihang River shifts its course southwest, where it is joined by the Lohit and Dibang Rivers. At this confluence, the river transforms and takes on the name Brahmaputra, marking the start of its iconic journey through the plains of Assam.

Upon entering Assam, the river becomes broader (wide upto 20 km in some parts of Assam) and more majestic, assuming the name Brahmaputra. It continues its journey westward through the state, forming one of the world's largest riverine islands, Majuli. 

The Brahmaputra then veers southward into Bangladesh, where it is known as the Jamuna. In its final stages, the river merges with the Ganges (Padma) and the Meghna rivers before emptying into the Bay of Bengal, creating a vast and fertile Sundarbans delta.

Brahmaputra River Tributaries

The Brahmaputra River is fed by numerous tributaries, which enhance its flow and contribute to its vast basin. These tributaries are classified into right and left bank tributaries:

1. Right Bank Tributaries:

• Lohit
• Dibang
• Subansiri
• Jiabharali
• Manas
• Torsa
• Sankosh
• Teesta 
• Ronganadi 
• Dikrong 
• Buroi 
• Borgong 
• Dhansiri (North) 
• Puthimari 
• Beki Aie

2. Left Bank Tributaries:

• Burhidihing
• Desang
• Dikhow
• Kopili
• Jinjiran
• Lhasa
• Krishnai 
• Noadehing 
• Bhogdoi 
• Dhansiri (South) 
• Kulsi Dhdhnoi

States Through Which the Brahmaputra Flows

The Brahmaputra River flows through three significant countries—China, India, and Bangladesh—enriching various regions along its course. In India, it traverses the following states:

1. Arunachal Pradesh: The Brahmaputra enters India through Arunachal Pradesh, where it is called the Siang or Dihang River. It flows down from the Himalayas, bringing immense water volume and carving fertile plains.

2. Assam: In Assam, the river is joined by numerous tributaries, such as the Lohit, Dibang, and Subansiri, significantly increasing its size. It creates vast riverine islands, including Majuli, and supports agriculture and biodiversity across the state.

3. West Bengal: The Brahmaputra flows briefly along the northern borders of West Bengal, playing a role in connecting the waterways and supporting the region's agricultural economy.

Cities Located on the Brahmaputra River

Several cities are situated along the Brahmaputra River, serving as cultural, economic, and administrative hubs. These cities benefit from the river's resources for agriculture, transportation, and trade. Key cities include:

1. Dibrugarh: Known as the "Tea City of India," Dibrugarh is a major commercial hub in Assam, with its economy heavily dependent on tea production and the Brahmaputra for transportation.

2. Tezpur: Often referred to as the "Cultural Capital of Assam," Tezpur is renowned for its historical sites and picturesque landscapes along the Brahmaputra.

3. Guwahati: The largest city in Assam and the gateway to Northeast India, Guwahati is a vital economic and cultural center. It hosts the famous Kamakhya Temple and is a major port along the river.

4. Jorhat: A prominent city in Assam, Jorhat is an important agricultural center and a key point for exploring the riverine island of Majuli, the world's largest inhabited river island.

5. Dhubri: Located in western Assam, Dhubri is a historically significant city and a key point near the Indo-Bangladesh border, where the Brahmaputra flows into Bangladesh.

6. Sadiya: Known as the gateway to Arunachal Pradesh, Sadiya lies at the confluence of the Lohit and Dibang rivers with the Brahmaputra and has historical importance as an ancient trade center.

Hydrological Significance

Spanning a total length of about 2,900 kilometers (1,800 miles), the Brahmaputra is one of the longest rivers in the world. It drains a vast basin covering approximately 580,000 square kilometers, supporting agriculture, transportation, and hydroelectric power generation. The catchments area of Brahmaputra in Tibet is 2, 93,000 Sq. Km; in India and Bhutan is 2,40,000 Sq. Km and in Bangladesh is 47,000 Sq. Km. 

The river is subject to seasonal fluctuations due to monsoon rains, often resulting in extensive flooding, particularly in Assam and Bangladesh. These floods, while destructive, also deposit nutrient-rich sediments, rejuvenating the soil and enhancing agricultural productivity.

Biodiversity and Ecology

The Brahmaputra basin is a biodiversity hotspot, home to numerous species of plants, animals, and aquatic life. The river supports the endangered Gangetic dolphin, a critical indicator of freshwater ecosystem health. The surrounding floodplains and wetlands are vital habitats for migratory birds, such as bar-headed geese and greater adjutants. Additionally, the river is a lifeline for rare and endangered terrestrial species, including the one-horned rhinoceros found in Assam's Kaziranga National Park.

Cultural and Economic Importance

Culturally, the Brahmaputra holds immense significance. It is revered in Hindu mythology and associated with numerous legends. Along its banks are temples and pilgrimage sites, such as the Kamakhya Temple in Guwahati. The river also supports vibrant cultural traditions and festivals, including the Bihu festival in Assam, which celebrates the agrarian lifestyle dependent on the Brahmaputra’s fertile plains.

Economically, the river is indispensable for millions of people. Its waters irrigate extensive agricultural lands, sustaining the cultivation of crops such as rice, tea, and jute. The Brahmaputra also serves as a vital waterway, enabling the transport of goods and people. Hydropower projects on the river and its tributaries are increasingly seen as key to meeting the region’s growing energy demands, though they also raise environmental and geopolitical concerns.

Challenges and Conservation

Despite its significance, the Brahmaputra faces numerous challenges. Seasonal flooding causes loss of life and property, while sedimentation alters its course and impacts navigation. Climate change exacerbates these issues by increasing glacial melt and altering precipitation patterns. Deforestation and unregulated development in the river basin contribute to erosion and habitat degradation.

Transboundary water disputes add a layer of complexity, as the river flows through multiple countries with differing priorities. Collaborative management between China, India, and Bangladesh is crucial for ensuring the sustainable use of the river’s resources.

Conservation efforts are essential to protect the river’s ecosystems and the communities dependent on it. Initiatives such as afforestation, sustainable agriculture, and the establishment of protected areas for biodiversity conservation are steps in the right direction. International cooperation and community-based management approaches can help address the multifaceted challenges facing the Brahmaputra.

Conclusion

The Brahmaputra River is much more than a geographical feature; it is a source of life, culture, and prosperity for the regions it traverses. Balancing development with conservation and fostering international cooperation are key to ensuring that this majestic river continues to nurture its people and ecosystems for generations to come.