The Ganga and Brahmaputra Systems
NCERT Class 9 • Contemporary India I • Chapter "Drainage" | NCERT Class 11 • India Physical Environment • Chapter "Drainage System"
The Ganga and Brahmaputra Systems
The Ganga rises at Gangotri glacier as the Bhagirathi and becomes the Ganga at Devprayag after joining the Alaknanda. It enters the plains at Haridwar, flows about 2525 km through India, and joins the Brahmaputra in Bangladesh to form the world's largest delta.
The Ganga and Its Tributaries
- Headstreams: Bhagirathi from Gangotri and Alaknanda; they meet at Devprayag.
- Left-bank tributaries come from Nepal Himalaya: Ghaghara, Gandak, Kosi.
- Right-bank tributaries come from the peninsula: Yamuna, Son.
- The Yamuna is the longest tributary; it rises at Yamunotri and joins the Ganga at Prayagraj.
- The Kosi is called the "Sorrow of Bihar" because it shifts its course and floods often.
- The Son joins the Ganga near Patna from the south.
- The Ganga plain is built of alluvium carried down from the Himalaya.
| Tributary | Bank | Source Region |
|---|---|---|
| Yamuna | Right | Yamunotri, Himalaya |
| Ghaghara | Left | Nepal Himalaya |
| Gandak | Left | Nepal Himalaya |
| Kosi | Left | Nepal Himalaya |
| Son | Right | Amarkantak plateau |
The Brahmaputra
- Rises in Tibet near Mansarovar lake, east of the Indus and Satluj sources.
- Called Tsangpo in Tibet, Siang or Dihang in Arunachal Pradesh, Brahmaputra in Assam, Jamuna in Bangladesh.
- It takes a sharp U-turn around Namcha Barwa and enters India.
- In Tibet it carries little water; in India heavy rain makes it a huge, silt-rich river.
- It has a braided channel with many riverine islands, including Majuli, a very large river island.
- Every year it causes floods and heavy bank erosion in Assam.
The Ganga Plain and Its Uses
- The Ganga basin is the largest river basin in India and supports a very dense population.
- Its alluvial soil makes it one of the most fertile farming belts in the country.
- Kanpur, Prayagraj, Varanasi, Patna and Kolkata all grew on or near this river.
- The Farakka barrage in West Bengal diverts water towards the Hooghly to keep Kolkata port usable.
- Canal systems drawn from the Ganga and its tributaries irrigate large parts of Uttar Pradesh and Bihar.
- In Bihar the river divides the state into a north bank and a south bank with different flood behaviour.
The Sundarbans Delta
Below Farakka the Ganga splits. One arm becomes the Hooghly in West Bengal; the main flow enters Bangladesh as the Padma, meets the Brahmaputra, and together they build the Sundarbans delta — the world's largest delta, famous for mangrove forests and the Royal Bengal tiger.
Doab — the land between two rivers, as in the Ganga-Yamuna doab.
Exam me kaise aata hai
- Which river is called the Sorrow of Bihar? — Kosi
- The Ganga is formed at — Devprayag
- Largest river island in the Brahmaputra — Majuli
- Tsangpo is the Tibetan name of — Brahmaputra
UPSC/State PSC ke liye
- The Kosi carries a very heavy silt load from Nepal, so it keeps raising its bed and shifting west.
- The Brahmaputra's braiding results from a high silt load plus a sudden drop in gradient at the plains.
Yahan confuse hote hain
✗ Ganga rises at Devprayag | Bhagirathi rises at Gangotri; Ganga is named at Devprayag | ✓
✗ Yamuna is a left-bank tributary | Yamuna joins the Ganga from the right bank | ✓
✗ Brahmaputra rises in Assam | It rises in Tibet as the Tsangpo | ✓
Ek nazar me
- Ganga: Gangotri to Bay of Bengal, about 2525 km in India.
- Left tributaries from Nepal, right tributaries from the peninsula.
- Brahmaputra: Tsangpo in Tibet, braided in Assam, Majuli island.
- Ganga and Brahmaputra together build the Sundarbans delta.