Sunday Observer Online


Sunday, 9 February 2014





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Government Gazette

The Water Cycle

What really is the Water Cycle?

Do you know that fresh water which you drink is not fresh? It has been earlier used in one way or the other somewhere in the universe. If you keep a glass of water in the sunlight, you will realise that some of it disappears,. Do you know what happens to this water?. When we wash clothes and put them out to dry, all the water evaporates in the air. Then this water comes back again to earth in the form of rain. It may fall on the ground or in a river or into the sea. Do you realise that all the water in the universe keeps moving in a cycle from pond to air and then again back as rain , that is why it is called the water -cycle.

Here are five different processes in a water cycle.

1. Evaporation

When a liquid, in this case water, changes from its liquid state to a gaseous state due to some heat factors it is called Evaporation. Our clothes dry when we put it out due to it.

2. Condensation

It is the opposite of evaporation. Condensation occurs when a gas changes into a liquid. This happens when heat is lost. Dew drops are formed due to this. When water vapour in the air touches grass, which has become cold due to low night temperature, the water vapour becomes liquid. Hence we see water drops on the grass in the morning.

3. Infiltration

It is process where rain water gets infiltrated (soaked) into the ground. Due to this we get ground water for drinking and irrigation of crops.

4. Precipitation

Rain is due to this. When atmospheric pressure is appropriate; temperature in higher skies becomes low, small quantities of water vapour join together to form big droplets. These big droplets can't bear their own weight and start falling as raindrops.

5. Transpiration

The plants absorb water from the soil through their roots, it passes from the stem and reaches the leaves. Some of this water is lost by the leaves due to the heat of the atmosphere. This is also a kind of evaporation, but here water from plants evaporates into the air.


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