Topographical maps show the height of the land. The "contour lines" on the maps represent changes in elevation, usually measured in feet. When contour lines are close together, the slope is steep. When the lines are far apart, the slope is gradual. Topographical maps help us picture how the land looks. By creating sand maps and laying loops of yarn around the sloping mounds of sand, kids better understand how to read topographical maps.
What this activity will develop:
Science and thinking skills
What you'll need:
• Large cardboard box
• Scissors or knife
• Trash bag
• Spray water bottle
1. Cut down the box sides to make a large, sturdy tray.
2. Line the inside of the box with the trash bag.
3. Fill the box with sand.
4. Spray the sand with water until it is damp.
What to do:
Mold the damp sand into a model landscape. Include several different landforms: mountains, hills, canyons, streams, valleys and lakes. Cut the yarn into a variety of lengths. Knot the ends of each piece together to make loops of various sizes. Find an elevation in the sand model on which to lay each loop so its height will be the same all around. Continue until there is a series of yarn lines at regular intervals on the model.
Stand above the model. From this birds-eye view, draw a map of the model on paper. Draw the yarn loops as contour lines. Flatten the sand in the box. Challenge a friend to re-create the landforms in the sandbox, using the map.