Classroom Compass
Volume 1, Number 1
Spring 1994

Stream Works

You will need: Stream pan, 2cm x 50cm x 10cm with drain hole at one end of the pan (1 per working group) Rubber tubing, 1 cm in diameter (2 lengths per group, approx. 25 cm each) Buckets (2 per group) Sand Books or bricks for support Screw clamp (1 per group)

By the time students reach the higher grades they should be developing some understanding of the explanations that underlie the phenomena they have been describing. While this activity has many surface similarities to "Mud Slide," it should be presented in ways that allow students to develop and test more sophisticated understandings of the process and to test explanations for the events they observe. Students will again build their own terrain and will control various factors involving erosion, sedimentation, and change in the landscape. In their investigation they will observe how a stream's ability to erode and deposit earth material is affected by a change in its flow.

Each group will develop a model of a landscape. Have each group set up a stream table with the pan holding the sand and the books or bricks producing a slight elevation to the landscape. Water, which is siphoned from the bucket placed above the stream table, is regulated by the screw clamp around the tubing. The water drains through the stream pan and out the pan hole into the second bucket.

With this basic setup, the students can construct several variations that reflect actual drainage situations. They can measure the amount of material moved through the model and devise explanations and predictions regarding the forces at work. Debris might be added for blockage. Lakes, hills, plants and other additions will alter the water's flow. To make connections between mathematics and science, measure the amount of water released, the incline of the slope, the amount of sand moved, the velocity of the water, and the stream volume.

To translate the model into a real event, the students might be asked to develop plans to prevent or manage the devastation of flooding in a local situation or an area reported in a news event, such as the Mississippi River.

The Teacher as Facilitator