In this activity, you will be making a model of a river in groups of 4.

Your teacher will provide you with the following materials:

– a large rectangular pan

– rock fragments of different sizes, including clay, sand, gravel and pebbles

– a bucket filled with water

– a timer

– safety goggles

Steps to follow:

1. Put on your safety goggles.

2. Pour the rock fragments into the right side of the pan. They should have a height of approximately five cm.

3. Add water to the left side of the pan, in order to create a representation of a lake.

4. Slowly add water, drop by drop, to the right side of the basin, just above the rock fragments. Continue this process for one minute. Record your observations in your science journal. Then, share them with your group.

5. Repeat the activity but increase the rate of flow to create a small, steady stream. Record observations and changes in your science journal. Comment on how the water flows through the different materials and its affects. Talk about your ideas with your group.

6. Predict what will happen if you increase the flow of the water again and also hold the pan on a downward angle.

7. Test your hypotheses and draw or write your observations in your science journal. Also, explain why you think what you saw happened.

8. Talk to your group members about your thoughts, predictions and observations. Then, when your teacher indicates, discuss your ideas with the class.

Click the river to continue.