Brahmaputra Floods

Why in News?

• Severe flooding in the Brahmaputra basin has affected parts of Assam and neighbouring States, following intense monsoon rainfall and increased river discharge.

Brahmaputra River – Key Facts

• Source: Chemayungdung Glacier (Angsi Glacier region) near Mount Kailash, Tibet.
• Length: Approximately 2,900 km.
• Countries: China (Tibet) → India → Bangladesh.
• Names:
  • Yarlung Tsangpo – Tibet
  • Siang (Dihang) – Arunachal Pradesh
  • Brahmaputra – Assam
  • Jamuna – Bangladesh
• Outfall: Joins the Ganga (Padma) and later the Meghna before emptying into the Bay of Bengal.

Major Tributaries

Left-bank Tributaries

• Dibang
• Lohit
• Burhi Dihing
• Dhansiri (South)
• Kopili

Right-bank Tributaries

• Subansiri
• Kameng (Jia Bharali)
• Manas
• Sankosh
• Beki
• Dhansiri (North)

Why is the Brahmaputra Highly Flood-Prone?

• Heavy monsoon rainfall across the Himalayan catchment.
• Snow and glacier melt during summer.
• Very high sediment load, causing frequent changes in river channels.
• Steep gradient in upper reaches followed by a sudden flattening in Assam, reducing flow velocity.
• Braided river system with numerous sandbars (chars).
• Riverbank erosion, leading to shifting channels.
• Climate change, increasing the frequency of extreme rainfall events.

Significance

• One of the largest river systems in Asia.
• Lifeline of Assam’s agriculture, fisheries and inland water transport.
• Supports the Kaziranga National Park and several wetland ecosystems.
• Declared National Waterway-2 (NW-2) from Dhubri to Sadiya.

Flood Management Measures

• Embankments and flood-control structures.
• Flood forecasting by the Central Water Commission (CWC).
• India Meteorological Department (IMD) early warning systems.
• Satellite-based flood monitoring.
• Basin-wide integrated river management and wetland conservation.

UPSC Prelims Question

Q. Consider the following statements regarding the Brahmaputra River:

1. It originates in Tibet where it is known as Yarlung Tsangpo.
2. The Subansiri and Manas are right-bank tributaries of the Brahmaputra in India.
3. The Brahmaputra is declared National Waterway-2 in India.

Which of the statements given above is/are correct?

A. 1 and 2 only
B. 2 and 3 only
C. 1, 2 and 3
D. 1 and 3 only

Answer: C

Explanation

• Statement 1: Correct. The river originates in Tibet as the Yarlung Tsangpo.
• Statement 2: Correct. Subansiri and Manas are major right-bank tributaries of the Brahmaputra.
• Statement 3: Correct. The stretch from Dhubri to Sadiya is designated as National Waterway-2 (NW-2).