As previously stated the water on the earth continually recycles itself and that water or hydraulic cycle is the method through which this occurs. The easiest way to explain this is to begin with the ocean water. The surface water in the ocean is warmed by the sun and evaporates into water vapor. It rises into the air and drifts up as air currents lift it and push it possibly hundreds of miles over land. The water droplets are lifted even higher where they get into colder air. At this point the vapor changes back into a liquid (condensation). Here it may condense on a tiny particle of dust, smoke and salt crystals, to become part of a cloud. After a while this vapor joins with other vapors to become a large drop which earth’s gravity pulls down to the surface. Depending on where it falls the raindrop can end up in a variety of places. If it lands on sidewalk or a leaf it will probably evaporate (transpiration) and begin its journey through the cycle again. If it lands on the ground and goes down into an underground aquifer it could be tens of thousands of years before the raindrop finds its way out of the ground again. It could run into an underground well and be pumped out to irrigate crops or for use by people to drink, bath with or wash their clothes. From these places it will either go back into the air or go down the sewers and into rivers and eventually back into the ocean or back underground. 15
In order for students to internalize an understanding of the rain cycle students will prepare stick puppets and act out the water cycle.
Objective: Students will make stick puppets of the sun, the earth, a raindrop, a cloud and a leaf.
Materials:
Patterns of the sun, the earth, a raindrop, a cloud, and a leaf.
Pencils
Tag board
Glue
Thin craft sticks
A variety of water markers
Procedure:
1. Students trace a copy of each pattern on a piece of tag board.
2. Cut out all pieces.
3. Color each piece appropriate colors.
4. Attach one stick to each pattern. Allow pieces to dry overnight.
5. Students can review the rain cycle by using the hands on puppets to illustrate each step.
The earth is heated by the sun. Water evaporates and forms a cloud. When the cloud becomes filled with rain droplets it begins to rain. The rain drops fall possibly on a leaf where it later evaporates (transpiration) or it follows a path underground or falls into a stream where it goes back into the ocean and the cycle begins again.
