Water
is always moving, wherever it is: through the air,
on the earth's surface, or under the ground.
The
five stages of the water cycle are noted in the image below.
Mouse over each of them or scroll down to learn more.
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| 1. |
Precipitation:
Water falls to earth from the clouds. It may
come as rain, hail, sleet, or snow, but all precipitation is water
in one shape or another.
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| 2. |
Run-off:
During the cold winter, most of Canada’s
precipitation is stored on the ground as snow and ice. When it melts
in the spring, a lot of water is suddenly set free and we can get
a heavy run-off of water into the rivers and lakes.
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| 3. |
Infiltration:
A lot of rainwater (or melted snow) infiltrates
or sinks into the ground. The roots of trees and plants take up
some of this water; the rest keeps moving downward. The water finds
its way into tiny spaces between bits of soil and into the cracks
in bedrock.
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| 4. |
Transpiration/Evaporation:
Up on the earth’s surface, the sun heats
up the water in puddles, rivers and lakes, and even the surface
of the ocean. As water gets warmer, it begins to evaporate into
the air as water vapour. Trees and plants give off water vapour,
too, through transpiration from their leaves.
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| 5. |
Condensation:
Water vapour rises into the sky and forms
clouds. Clouds can travel a long way, blown by the wind, carrying
water from one part of the world to another. Sooner or later, though,
the water in the clouds will change its form again. Condensation
happens when the water vapour cools down and turns into liquid water.
Too heavy to stay up in the clouds, the raindrops fall...and the
“water cycle” starts all over. |
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