UPSC Prelims 2013 Q16: Geography – Oceanography
On the planet Earth, most of the freshwater exists as ice caps and glaciers. Out of the
remaining freshwater, the largest proportion
- (a) is found in the atmosphere as moisture and clouds
- (b) is found in freshwater lakes and rivers
- (c) exists as groundwater
- (d) exists as soil moisture
Answer: (c) exists as groundwater
Explanation
Where the Earth's freshwater is
Only about 2.5 to 3 percent of all water on Earth is fresh.
| Store of freshwater | Share of freshwater (about) |
|---|---|
| Ice caps and glaciers | 69 percent |
| Groundwater | 30 percent |
| Lakes, rivers, swamps | Less than 1 percent |
| Soil moisture | Very small |
| Atmosphere | Very small |
So, after ice, the largest share is groundwater.
All water on Earth:
| Store | Share |
|---|---|
| Oceans | About 97 percent |
| Freshwater | About 3 percent |
India is the world's largest user of groundwater, mainly for irrigation.
Answer: (c) exists as groundwater.
Why each option is right or wrong
- (a) Incorrect. The atmosphere holds only a tiny fraction of freshwater.
- (b) Incorrect. Lakes and rivers hold less than one percent of freshwater.
- (c) CORRECT. After ice, the largest proportion of freshwater exists as groundwater.
- (d) Incorrect. Soil moisture is a very small store.
Key point
Freshwater: about 69 percent ice caps and glaciers, 30 percent groundwater, under 1 percent in lakes and rivers. Oceans hold 97 percent of all water.
Remember
After ice, groundwater is the biggest freshwater store.
Common mistakes
- Thinking rivers and lakes hold most usable freshwater.
- Overestimating water in the atmosphere.
- Confusing shares of all water with shares of freshwater.
Exam tip
Freshwater order: ice, groundwater, surface water.
Sources
- NCERT Class XI — Fundamentals of Physical Geography, Ch 13 (Water: Oceans)
- NCERT Class VII — Our Environment, Ch 5 (Water)