RAS question
Which river has the largest drainage basin in India?
Correct answer: (C) Ganga.
The Ganga has the largest drainage basin among the rivers listed for India.
Explanation
The Ganga is the right answer because the Ganga basin is India's largest river basin, at about 8.6 lakh sq km in India and roughly 26% of the country's total area. The verified India-WRIS river-basins page supports this ranking through its basin-area table: it lists the Ganga Basin at 8,08,334.44 sq km, while the Godavari, Brahmaputra and Indus up to border basins are listed with smaller Indian basin areas. For an exam question asking the largest drainage basin in India, the key is to compare the basin area within India, not the global length or international spread of a river system.
Why the other options are wrong
- (A) Godavari is the largest basin among peninsular rivers, but India-WRIS lists its basin area below the Ganga basin.
- (B) Brahmaputra is not the largest within India because much of its basin lies outside India, and the India-WRIS table gives it a smaller Indian basin area than Ganga.
- (D) Indus is not the answer because a large part of the Indus system lies in Pakistan, and India-WRIS lists the Indus up to border basin below Ganga in area.
Concept
This tests Indian drainage systems, especially the distinction between river length, international river systems and drainage-basin area within India. RAS repeats this concept because basin size matters for irrigation, floods, planning and inter-state water questions.