CECsci.190


TITLE:    The Water Cycle

AUTHOR:   Vilia Natchez, Our Lady of the Snows School,
          Reno, Nevada

GRADE LEVEL:   Appropriate for grades 2-4

OVERVIEW:  The water cycle explains the sun heating the
earth's surface water so that it evaporates.  This vapor
gathers in  clouds which rise to the cold air.  When those
clouds become too heavy to float, they release their
moisture as precipitation.  The precipitation collects in
lakes or oceans after siphoning through soil or running down
rivers.  It then evaporates and repeats the cycle once
again.

OBJECTIVE(s):  Students will be able to:
1.  Explain how the water cycle recycles the earth's
    water supply.
2.  Make use of the knowledge of landforms learned in
    social studies.
3.  Form a hypothesis on how/why the water cycle works.
4.  Use language arts skills of writing and drawing to
    explain how the cycle works.

RESOURCES/MATERIALS:
Assemble these materials:
  soil
  water
  small margarine bowl
  large, clear plastic container.or an old aquarium
  plastic wrap
  plastic trees, animals, boat, etc. are optional
  tape or large elastic band
  bag of ice (optional)
  heat lamp (optional)

ACTIVITIES AND PROCEDURES:
1.   Arrange the soil in the container to make mountains,
     plateaus, hills, etc., and a lake basin. Place the
     margarine bowl in the lake basin.  Fill the bowl with
     water.  The plastic toys may be added to appeal to the
     children's imaginations.  Cover the container tightly
     with plastic wrap and secure it by means of tape or the
     band.
2.   Discuss what is expected to happen in the container.
3.   Depending on the amount of sun, the project may take 1-
     3 days.  In order to speed the process, a bag of ice
     may be placed on one end of the covered container,
     while a heat lamp is focused on the other.
4.   Watch for condensation  on the plastic "sky" of the
     container.  When enough moisture collects, it will fall
     onto the landforms as precipitation.
5.   Compare the hypothesis to actual results by discussion.
6.   Encourage the students to draw the water cycle using
     arrows to show the flow.
7.   Ask the students to write a paragraph explaining their
     picture.  A word bank might be used if needed.
     Possible words for the bank are: condenses (cools),
     vapor, clouds, evaporate, precipitation (rain/snow),
     heavy, soil, oceans, lakes.  Try to elicit these words
     from the students.