RAS question
The Amazon River basin is the largest river basin in the world by area. It is primarily located in which country?
Correct answer: (B) Brazil.
The Amazon River basin is primarily located in Brazil, which contains the largest share of the Amazon watershed.
Explanation
The Amazon basin is the world's largest drainage basin, covering about 70 lakh sq km, and the question asks where this vast basin is mainly located. The official World Bank feature describes the Amazon as a territory of more than seven million square kilometres and says its watershed spans eight countries. In that country-wise break-up, Brazil has the dominant share, listed at 61.8%, while the remaining countries have much smaller shares. Brazil is therefore the substantive answer: although the Amazon system extends across northern South America and the river is associated with several countries, the basin is primarily Brazilian by area. The approximate figure of about 60% in Brazil is consistent with the World Bank figure.
Why the other options are wrong
- (A) Venezuela is one of the Amazonian countries in the World Bank list, but Venezuela is associated mainly with the Orinoco basin, not the principal share of the Amazon basin.
- (C) Peru is important because the Amazon originates there, but origin is not the same as basin dominance; most of the basin lies in Brazil.
- (D) Colombia drains a smaller part of the Amazon system, but it does not contain the main area of the basin, which is mostly in Brazil.
Concept
This tests the World Geography concept of drainage basins and spatial distribution, where exam questions often distinguish a river's source, course and basin area. It recurs in RAS because major river basins are standard map-based facts with direct environment and geography relevance.