Model porečja

1. Make the model:

• Crumple a couple of sheets of newspaper and place them in the plastic container.
• Drape the plastic sheet over the crumpled paper in such a way that a valley and hills are formed. Be sure that water generally flows towards the valley and to the front side of the container.

• Fold up the front edge of the plastic sheet to prevent the water from overflowing. You have created a model of hills and valleys that form the watershed that drain towards the ocean.

2. Demonstration of a river watershed: Explain the students that the hills divide different watersheds. Spray the colored water onto the model and observe the movement of water. Point out how the water runs off the land on one side or the other side of the high ridgeline of hills, and forms streams in the valleys.

• What is a river watershed or a river basin? (All of the land that drains into one stream or river with all its tributaries is called a river watershed.)
• What is the high ridgeline? You can mark it on a model with a waterproof marker.
• How rapidly does the water travel over a hard surface? (The water flow is very rapid.)

Materials

• newspaper,
• large plastic bag or large sheet of plastic,
• paper towel,
• spray bottle filled with water,
• plastic container,
• waterproof marker,
• food coloring (add a drop or two to the water),
• sponge;

Worksheet

WATER CYCLE SCHEME