UPSC Prelims 2016 · Question 53 of 98

UPSC Prelims 2016 question on Brahmaputra Tributaries

Which of the following is/are tributary/tributaries of Brahmaputra?

1. Dibang
2. Kameng
3. Lohit

Select the correct answer using the code given below.

  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3
Show answer

Answer: D. 1, 2 and 3

Verdict

The answer is 1, 2 and 3. The Dibang, Kameng and Lohit are all tributaries of the Brahmaputra.

Analysis

All three rise in the eastern Himalaya within Arunachal Pradesh and drain south into the Brahmaputra. The Lohit joins in the extreme east, near where the Brahmaputra enters Assam, and the Dibang joins close by, the two together with the Siang forming the main stream. The Kameng, called the Jia Bhoroli in Assam, joins from the north further downstream. Since all three lie within the same eastern Himalayan drainage, none can belong to another system.

Source

NCERT Class XI, India: Physical Environment, page 26.

How to crack it

Use the geography of the source region as the filter. Any river rising in Arunachal Pradesh has nowhere to go except the Brahmaputra, because the State lies wholly within that basin, so identifying the State of origin settles tributary questions without a river list. Note the same logic applied in reverse for 2015's question on the Barak, which rises in Manipur and therefore belongs to a different system entirely. Basin thinking answers both.

More questions on Indian Geography

All 65 questions on Indian Geography →

← Full 2016 question paper · All Geography questions