Students will model the water cycle and predict what will happen.

Students will discuss the effects of the water cycle on the changing Chesapeake Bay area.

Background:
The sun's heat makes moisture evaporate from all kinds of surfaces, but mostly from oceans.  Water vapor condenses to form rain, hail, or snow that falls to earth again.  There, water runs off the land or soaks into the soil.  Either way, a lot of water returns to the sea.  Water is always traveling from the earth's surface up tot he atmosphere and back.  The round and round journey is called the water cycle.

Description:
This lesson will help students to create a model of a body of water and land.  They will simulate the water cycle and predict what will happen.

Materials (for each group):
1 bucket of soil, a large clear plastic box with a hole cut into one corner, lid and stopper, 1 large pad or paper towels, 1 plastic spreader, 1 spoon, 1 ruler, 2 had lenses, warm water, 1 piece of plastic wrap, 1 large rubber band, 1 ice pack

Procedure:
1.  Cover your workspace with the large pad.

2.  Place the clear plastic box on the pad.  make sure that the corner with the hole is on the edge of the table and that the stopper has been placed inside the hole from the inside of the box out.  Make sure that the stopper is pushed tightly so that it does not drain during the experiment.

3.  Dump the soil into one end of the plastic container.

4.  With the plaster spreader, push the soil away from the drain hole toward the opposite end of the box.  Pat the soil down tightly on top and create a slanted hill at the edge of the soil.  (The soil should only fill half of the container.)

5.  Pour the warm water into the box on the other end.  Do not pour the water on the soil.  You are creating a lake.

6.  Cover your land and water model with the plastic wrap and fasten the plastic with a large rubber band.

7.  Place the ice pack on the plastic so that it is above the land (soil).  Leave the ice for the next five minutes.

8.  After 5 or more minutes remove the ice pack from the plastic and discuss your observations.

9.  Tap gently on the plastic where you placed the ice pack.  Record your observations.

10.  After you have discussed and made your observations, place a bucket under the hole in your plastic box.  Drain you water out.

Discussion
1.  What happens inside the plastic box when we put the ice pack on top of the plastic wrap?

The warm water changed some of the water to a gas (water vapor).  The gas rises high into the cold air near the ice pack.  The cold air turns the gas back into water droplets.  Eventually the water falls back to the ground.

2.  What are the steps to this water cycle?

The water evaporates into the air, then condenses and precipitation falls back to the ground and runs off into the ocean to start the cycle over again.

3.  If pollution is increasing in the Chesapeake Bay, what do you think is happening to the water cycle?

The pollution that is running off into the bay is evaporating into the air and caused polluted precipitation such as acid rain.

Assessment
Students will label a blank representation of the water cycle.

Extension
Math - Students can use measuring equipment and convert values from metric to English units.

ELA - Students can record answers in a writing journal using prediction skills at the beginning of the lesson and explaining observations during the experiment.

Art - Students can draw pictures of the water cycle.