2. 2.Water –A Natural Resource

3. 22 March-World Water Day

4. We use water for many purposes-
Drinking
Cleaning
Cooking
washing

5. Sources of Water-
Wells
Tube-wells
Ponds
Lakes
Rivers

6. 97% of water on earth is in the seas
Of the remaining 3% of water. 2.7% is in the form of ice or is under ground

7. Forms of Water-
Liquid-Water
Solid-Ice
Gaseous form- Water vapour

8. To reduce evaporation of water-
Water evaporates at all temperatures from 0˚C to 100˚C .At higher temperatures, water evaporates faster.
To reduce evaporation of water-
A layer of cetyl alcohol is sprayed
Water is carried through large pipes
To save water, some plants are grown under plastic covers.

9. Pollution of water-

10. Pollution of Water-
Waste water from industries is allowed to flow into nearby sources of water without any treatment.Thus,water gets contaminated. This is called water pollution.
This is dangrrous for living things.
The Government has made strict laws for preventing the pollution of water.
The Government of India has undertaken a huge project for the purification of the water of the Ganga river.

11. Potable water-
At water treatment plants ,there are filtering machines to remove the impurities and destroy the germs in the water.Chlorine is also added to the water at the plant . This process is called chlorination.

12. Water management-
About three-fourths of the earth is occupied by water.
97% of this water is in the seas.
Only 3% of water can be used for drinking or other purposes.
Only 35 millilitres per 10,000 millilitres is available as drinking water.
Taking care on a personal level to use water sparingly,reusing water after suitable treatment rather than wasting it, reopening old wells that have become blocked. This is called water management.

13. Rainwater harvesting-
When rainwater is collected and used later , it is called rainwater harvesting.
Water that falls on the roofs of buildings is carried down through pipes and then stored into tanks or pits in the ground.
This helps to raise the level of ground water.

14. Thank you