Ranking Indian River Basins by Size

This solution explains how to arrange the given Indian river basins - Mahanadi, Godavari, Ganga, and Pennar - in descending order based on their geographical size (area). Understanding the relative sizes of major river systems is important for geography studies and competitive exams.

Analyzing River Basin Sizes

To determine the correct order, we need to look at the approximate area covered by each river basin:

• Ganga River Basin (C): This is one of the largest river systems in India, covering a vast area. Its total drainage area within India is significant, estimated around 861,000 square kilometers ($8.61 \times 10^5$ km$^2$).
• Godavari River Basin (B): Known as the 'Dakshin Ganga', the Godavari basin is the second-largest river basin in India. Its area is approximately 312,812 square kilometers ($3.13 \times 10^5$ km$^2$).
• Mahanadi River Basin (A): The Mahanadi basin is located in the eastern part of India, flowing through states like Chhattisgarh and Odisha. Its drainage area is roughly 141,589 square kilometers ($1.42 \times 10^5$ km$^2$).
• Pennar River Basin (D): The Pennar basin is a river system primarily located in the southern Indian states of Karnataka and Andhra Pradesh. Its area is estimated to be around 55,000 square kilometers ($5.5 \times 10^4$ km$^2$).

Comparative Table of River Basin Sizes

Determining the Descending Order

Arranging the river basins from the largest area to the smallest area, we get the following sequence:

1. Ganga (C) - $861,000$ km$^2$
2. Godavari (B) - $312,812$ km$^2$
3. Mahanadi (A) - $141,589$ km$^2$
4. Pennar (D) - $55,000$ km$^2$

Therefore, the correct descending order based on size is (C), (B), (A), (D).

Matching with Options

Comparing this derived order with the given options:

• Option 1: (D), (B), (C), (A) - Incorrect
• Option 2: (B), (C), (A), (D) - Incorrect
• Option 3: (B), (A), (D), (C) - Incorrect
• Option 4: (C), (B), (A), (D) - Correct

The order (C), (B), (A), (D) matches option 4.