Background
The Earth is a closed ecosystem.
All the water we have is on the planet; as it goes through the water
cycle, it is changed from one form to another. The three states of water
are solid, liquid and vapor. Most of the precipitation
in Colorado falls in the form of snow in the mountains. Coloradans
rely heavily on the snow fall not only for recreation but also for water
supply. We get 80% of our drinking water from snowpack.
The water cycle is a complex
system. The major parts of the cycle include:
Evaporation: the sun
evaporates water from ponds, lakes and the ocean and converts it to
vapor or gas, which eventually cools and turns into clouds.
Precipitation: water
that falls in the form of rain or snow from saturated clouds.
Infiltration: water
that reaches the earth, either runs off the surface, falls into a waterbody,
or infiltrates into the soil to collect underground.
Transpiration: underground
water may be soaked up by plant roots and carried into their leaves.
Water vapor is a by-product of plant transpiration, which uses solar
energy, water and nutrients to create nutrients.
Respiration: when
we breathe, small amounts of water vapor are released from our lungs.
Activity
Objective
This activity will introduce
the concept of the water cycle by using a simple demonstration.
Materials Needed:
- Clear plastic jar with
lid (or smaller container that fits on top of jar)
- Hot water
- Bag of ice
- Food coloring
How to:
Pour hot water into plastic
jar, filling it about 1/3 of the way. Add several drops of food coloring
to simulate dissolved material.Place inverted lid (or smaller plastic
container) on jar and fill with ice. Observe and discuss what is going
on.
Things to look for:
- Steam rising from warm
water (clouds)
- Drops forming on bottom
side of lid (rain)
Discussion
questions
1. What happens to the water
when it gets heated up?
2. What effect does the ice
have on the water?
3. Discuss the water cycle
as it occurs in nature.
4. How is this demonstration
similar?/different?
5. What are the three states
of water?
6. Where does most of the
precipitation fall in Colorado? What form is it in?
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