Make a Water Cycle Model

Water Cycle Model

The water cycle is one of
the most integral
concepts concerning
the functioning of our
planet Earth.

This activity helps children of all
ages understand the water cycle.





What You Will Need:

• Large Mixing Bowl or Aquarium
• Small Cup
• Soil or Newspaper
• Plastic Wrap
• Rubber Band

What You Do:

• Place a small cup in the center of a large mixing bowl or aquarium.
• Surround the small cup with wet soil or with wet, crumpled newspapers.
• Stretch a piece of plastic wrap over the mixing bowl and secure it with a rubber band.
• Place a small weight, such as a stack of pennies or small pebbles in the center of the plastic wrap, so that the center of the plastic wrap is slightly depressed over the cup inside the bowl.
• Set the bowl in a sunny area and watch what happens over a couple of days.
• After a day or two, condensation forms on the plastic. When the condensation droplets get larger, they will begin to run down toward the center of the plastic and drop off into the small cup. The concept of the water cycle has been completed! The water evaporated from the wet soil or newspapers, creating condensation on the underside of the plastic, causing precipitation to occur as the water droplets fell into the cup.

Variations:

• Place the water cycle model in a dry, dark area of your house and see how this contrasts to having the model in a sunny area. Encourage your children to think about how the sun (and warmth) is imporant to the water cycle.

One Step Further:

• Take opportunities to relate this water cycle activity to the real world - this will help reinforce what kids are learning. For example, when it is raining outside, ask your children to think about where the rain is coming from (clouds) and where is it going (soaking into the ground). Where will it go next? On a warm, sunny day, ask your children to think about what is happening to the water in lakes and streams (evaporation). On a cloudy day, what is happening to the water? Exploring the water cycle as it relates to every day living will help children remember this important lesson.

The Science:
The heat from the sun is absorbed by the wet material, causing it to be heated. The heating causes the water to evaporate (much like a puddle after a rain), building up a high concentration of water vapor (high relative humidity) in the bowl. The water vapor condenses on the plastic wrap cover, which is cooled by its contact with the cooler surrounding air. This is similar to the rise of water vapir into our atmosphere.