Question

Out of the available fresh water on Earth, the approximate percentage of groundwater is about:

• A. 3.0
• B. 30
• C. 7.0
• D. 70

Hint:

Groundwater is the second-largest store of freshwater, after glaciers and ice caps.

Answer 1

The Correct Option is B

To determine the approximate percentage of groundwater in Earth's available freshwater, we analyze global water distribution data.

1. Understanding Earth's Freshwater Resources:
- Total freshwater represents about 2.5% of Earth's water
- Of this freshwater, the majority is locked in glaciers and ice caps (~68.7%)
- Surface water (lakes, rivers) accounts for only about 0.3%

2. Groundwater Percentage:
- Groundwater constitutes approximately 30% of Earth's freshwater
- This makes it the second largest freshwater reservoir after glaciers
- The percentage varies slightly between sources but consistently falls near 30%

3. Data Verification:
According to:
- US Geological Survey (USGS) water science studies
- United Nations World Water Development Reports
- Recent hydrological research publications

4. Importance of Groundwater:
This 30% represents:
- The primary drinking water source for nearly 50% of the global population
- About 40% of irrigation water worldwide
- A critical buffer against climate variability

Conclusion:
The correct approximate percentage of groundwater in Earth's available freshwater is 30%.

Final Answer:
The correct option is: 30.