Question.
Why do you think most of the water on Earth cannot be used for drinking or farming?
( Chapter 1: Water-The essence of Life, Class 5-EVS NCERT-Our Wondrous World)
Answer.
Most of the water on Earth cannot be used for drinking or farming because about 97% of it is found in oceans and seas, where the water is salty. Salty water is not suitable for drinking or irrigation.
Only a small amount of water on Earth is fresh water, and much of it is trapped in glaciers, ice caps, or deep underground. Therefore, very little fresh water is easily available for human use.
The following reasons explain why most water cannot be used for drinking or farming:
1. Most water is salty:
About 97% of Earth’s water is found in oceans and seas and contains a large amount of salt. Humans and most land animals cannot drink salty water because it can cause dehydration and other health problems.
Plants absorb water from the soil through a process called osmosis. Salty water contains excess salt, which prevents plant roots from absorbing water and nutrients properly. As a result, plants dry up and may die.
2. Fresh water is very limited:
Only about 3% of Earth’s water is fresh water. Out of this, nearly 2% is frozen in glaciers and polar ice caps. Thus, only about 1% of Earth’s water is easily available for human use, and it is not equally distributed everywhere.
3. Polluted water is unsafe:
Much of the fresh water available in rivers, lakes, and ponds is polluted by waste, sewage, and chemicals. Such water is unsafe for drinking and farming.
4. Water treatment is expensive:
Converting salty or polluted water into usable water requires special treatment processes, which can be costly and difficult.
Therefore, usable fresh water is limited, and we should save water and use it wisely.
You may also like:
ConversionConversion EmoticonEmoticon