CDS (II) 2022 General Knowledge · Question 2 of 120

Correct — A, Dhaleswari. The Barak rises in the Manipur hills south of Mao in Senapati district, at about 2,331 m, runs along the Nagaland-Manipur border and turns west into the Cachar plain of Assam; in Bangladesh it divides into the Surma and the Kushiyara and reaches the sea through the Meghna. India-WRIS, the Ministry of Jal Shakti's water resources information system, lists its south-bank tributaries as the Dhaleswari, Singla, Longai, Sonai and Katakhal, and its north-bank tributaries as the Jiri, Chiri, Modhura, Jatinga, Harang, Kalain and Gumra. Only the Dhaleswari appears in that list. The other three names belong to a different river system altogether — every one of them feeds the Brahmaputra.

• (b)Subansiri — The Brahmaputra's largest tributary. It rises in Tibet, cuts south through Arunachal Pradesh as an antecedent river — older than the mountains it saws through — and joins the Brahmaputra on its right bank in Assam. It never comes near the Barak.
• (c)Dhansiri — A Brahmaputra tributary as well, and the name is used twice in the northeast: the southern Dhansiri drains the Nagaland hills past Dimapur into the Brahmaputra's left bank, and a second Dhansiri joins from the north bank in Darrang. Neither drains into the Barak.
• (d)Manas — Comes off the Bhutan Himalaya and joins the Brahmaputra's right bank in western Assam, giving its name to Manas National Park. UPSC has itself used 'Manas : Brahmaputra' as the one correctly matched pair in a tributary question.

The northeast carries two separate river systems and candidates routinely fuse them. The Brahmaputra drains the wide Assam valley between the Himalaya and the Meghalaya plateau, gathering the Subansiri, Kameng, Manas and Sankosh from the north and the Burhi Dihing and Dhansiri from the south. The Barak drains the hill country to the south of that — Manipur, Mizoram, southern Assam — and never joins the Brahmaputra inside India. The two meet only in Bangladesh, where the Meghna, fed by the Barak, merges with the Padma-Jamuna system.

The stem's phrasing is loose and it is worth reading carefully: the Dhaleswari itself rises in Mizoram, where it is called the Tlawng, and joins the Barak in the Cachar plain of Assam rather than inside Manipur. 'In Manipur' attaches to the Barak, the river that rises there, and not to the tributary. Once you set that aside the item is a clean sort by river system. Subansiri, Dhansiri and Manas are three of the standard Brahmaputra tributaries that every textbook list carries, so the safe method is elimination: knock out everything you can place on the Brahmaputra and one name is left. A caution on the name itself — there is a second Dhaleshwari in Bangladesh, a distributary of the Jamuna, which is a different river.

• India-WRIS records that the Barak rises in the Manipur hills south of Mao in Senapati district at an elevation of 2,331 m.
• Its south-bank tributaries are the Dhaleswari, Singla, Longai, Sonai and Katakhal; the north-bank ones include the Jiri, Chiri, Jatinga and Gumra.
• On entering Bangladesh the Barak splits into the Surma and the Kushiyara, which rejoin as the Meghna.
• The Dhaleswari is known as the Tlawng in Mizoram, where it rises, and it meets the Barak in the Cachar plain of Assam.
• The Subansiri, which rises in Tibet, is an antecedent river and the largest tributary of the Brahmaputra.

• Treating every large northeastern river as a Brahmaputra tributary — the Barak system is separate inside India.
• Confusing the Dhaleswari of the Barak system with the Dhaleshwari of Bangladesh, which comes off the Jamuna.
• Assuming the phrase 'in Manipur' describes the tributary; it describes the Barak, which rises there.

As a single-name tributary question like this one, as a tributary-to-main-river matching pair, or as a statements item on where the Barak rises and which river it eventually feeds.

• practice — not a real PYQ

  The Barak river finally joins which one of the following rivers before reaching the Bay of Bengal?

  • (a)Brahmaputra
  • (b)Meghna
  • (c)Ganga
  • (d)Teesta

  Answer(b) Meghna — in Bangladesh the Barak divides into the Surma and the Kushiyara, which reunite as the Meghna.

• practice — not a real PYQ

  Which one of the following is a left-bank tributary of the Brahmaputra?

  • (a)Manas
  • (b)Kameng
  • (c)Dhansiri
  • (d)Sankosh

  Answer(c) Dhansiri — the Manas, Kameng and Sankosh all join the Brahmaputra from the right bank, while the Dhansiri (South) comes in from the left.