THE WATER CYCLE

 The  'water cycle' is  the continuous movement of water on earth. There is only a limited amount of water on our planet, and this same amount goes round and round in  an endless  cycle, changing from liquid to gas and back to liquid again.


The glass of water on your table may have been rain only a week ago, but it has been around for million of years!

There are four main stages of the water cycle. The first stage is evaporation. This is when the water in seas, lakes and rivers is heated by the sun, and turns into vapour, or gas. This vapour rises in the atmosphere. The next stage, condensation, is when the vapour gets cold and becomes liquid again, forming tiny water droptes that make up the clouds in the sky.

The third stage is precipitation. This happens when the atmosphere is so full of water that it is too heavy for the air to hold. This is when it rains, hails or snows.


The final stage is collection. The precipitation (rain, hail or snow) either falls back into the seas, rivers and lakes, or falls on the ground. When it falls on the ground, some of it is absorbed by the earth and becomes part of what is called "ground water", which is what plants and animals use. The water that runs over the ground flows back to the lakes, the rivers and the oceans, where the cycle begins again.