Previous Year Question
Which one of the following river basins is the largest in respect to area?
Cauvery
Narmada
Mahanadi
Tapti
Correct Answer: C
Detailed Solution
Among the four given options, the Mahanadi has the largest river-basin area. A river basin refers to the entire catchment area from which surface runoff reaches a common river system through the main river and its tributaries.
The total area of the Mahanadi Basin is about 141,589 sq km. In comparison, the Narmada Basin covers 98,796 sq km, the Cauvery Basin 81,155 sq km and the Tapi Basin 65,145 sq km.
Thus, the basin-area sequence among the given options is—Mahanadi > Narmada > Cauvery > Tapi.
It is important to distinguish between river length and basin area. For example, the Narmada is longer than the Mahanadi, but its drainage basin is smaller. Therefore, river length alone cannot be used to determine the answer.
The Mahanadi Basin extends mainly across Chhattisgarh and Odisha. The river flows eastwards and ultimately drains into the Bay of Bengal, forming an extensive delta in its lower course.