Find pics The water cycle

The earth has a limited amount of water.

Monday, April 07, 2008

The earth has a limited amount of water.

That water keeps going around and around and around and around and this is what we call the "Water Cycle".

This cycle is made

up of a few main parts:

(I) Evaporation

(and transpiration)

(ii) Condensation

(iii) Precipitation

(iv) Collection

Evaporation:

Evaporation happens when the sun heats up water in rivers or lakes or the ocean and turns it into vapour or steam. The water vapour or steam leaves the river, lake or ocean and goes into the air.

Do plants sweat?

Well, sort of.... people perspire (sweat) and plants transpire. Transpiration is the process by which plants lose water out of their leaves. Transpiration gives evaporation a bit of a hand in getting the water vapour back up into the air.

Water vapour in the air gets cold and changes back into liquid, forming clouds. This is called condensation.

You can see the same sort of thing at home... pour a glass of cold water on a hot day and watch what happens.

Water forms on the outside of the glass. That water didn’t somehow leak through the glass! It actually came from the air. Water vapouur in the warm air turns back into liquid when it touches the cold glass.

Ends