Guyana Water Incorporated

Water Cycle

How does the Water Cycle work?

The Water Cycle allows for the same water – that probably existed for thousands of years - to return to the Earth as rain. The Water Cycle “re-cycles” the water we use. This involves three (3) basic processes which are:

• Evaporation
• Condensation
• Precipitation

1. Evaporation:

Have you ever observed your mom or dad boil water in a kettle or pot? Evaporation occurs when the water turns to steam and rises from the kettle. In the Water Cycle, evaporation occurs when the sun warms rivers, oceans, lakes and streams and turns that water into water vapour or steam. The water vapour rises from the river and goes in to the air.

2. Condensation:

Condensation occurs when the water vapour in the air becomes cold and forms liquid again – changing into clouds. To see this happen for yourself observe a glass of cold water on a hot day. You will notice water forming on the outside of the glass. This happens because water vapour in the warm air turns back in to liquid when it comes in to contact with the cold glass. Be sure to try it for yourself.

3. Precipitation:

Precipitation occurs when the water has condensed and the air can no longer contain it. The clouds become heavy and eventually allow the water to return to the Earth as rain filling our rivers, lakes and streams. The water may also return to the Earth in the form of snow, sleet or hail.

When the water returns to the Earth as precipitation, it is collected by rivers, streams and lakes. Some of it falls on land where it is soaked in and becomes ground-water which we use to drink.

Then, the cycle starts all over again when the sun-light heats up that water and it evaporates in to the air and forms clouds…

Do plants contribute to the Water Cycle?

You got it! Plants and trees also produce water vapour through transpiration. It’s the process by which plants lose water through their leaves. This water floats into the atmosphere and eventually becomes precipitation as well. I guess we can say that transpiration helps evaporation to get the water back in to the atmosphere.

Activity:

• Boil Water in a kettle to represent the sun evaporating from the sea and rivers
• Position a cold tile in the steam; the water vapour will cool and condense into “raindrops”.
• Collect the water in a cup

“Sweating Plant”

• Place a transparent plastic bag over a busy plant – tie the bag tightly – and leave it outside in warm air. After a few hours water vapour transpiring from the plant will appear as droplets within the bag.

Activities teachers can conduct with their students:

• Stubborn Stan says “Guyana is the land of many waters; I don’t have to worry about how I use it!” Think of 5 things that you would say to Stubborn Stan about his attitude towards water.

• Have children describe how their lives would be different living in a country with no water or sewage treatment.

• Plan a “water audit” – showing information about all the ways YOU use water in the home or school and share your results with the rest of the class. Present information on a graph or chart. Think of ways that you can persuade people at home or school to use water wisely.

Water is life! Do not waste it!