Which river basin has the highest total replenishable ground water resources?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Ganga
Replenishable groundwater is the groundwater that is filled up again every year, mainly by rain water and by water from rivers, canals and fields that soaks into the ground. A basin gets more of it when it is large, receives good rain and has soft, deep soil.
Option (1) Godavari — Incorrect. It is the largest basin of peninsular India, but most of it lies on the hard rocks of the plateau. Water soaks into such rocks slowly.
Option (2) Ganga — Correct. It is the largest river basin of India. Its wide plains of deep alluvium get good monsoon rain and are crossed by many rivers and canals, so a very large amount of water reaches the groundwater every year.
Option (3) Brahmaputra — Incorrect. It gets very heavy rain, but only about a third of it lies in India, and its valley in Assam is narrow.
Option (4) Mahanadi — Incorrect. It is a much smaller basin in eastern India, and much of it lies on old hard rocks.
Note: This question is not from NCERT. NTA does this once in a while, but such questions are very few. Your NCERT is still enough.