Concrete Contour Mapping

One of the challenges of understanding maps is making the jump from the image on the page to the reality of the world. This is especially challenging when it comes to scale, both distance and elevation. When we work on contour mapping, there are always several students in the class who have a hard time picturing how those lines on the map turn into hills, mountains, and valleys. 

I decided to make the idea of contour mapping more concrete for them.

Materials: 

• play-dough or plasticine in 4 or more different colours (one being blue)
• dark blue heavy-gauge poster board, cut to size
• pencil or chop-stick
• graph paper

I chose to make up a few batches of play-dough, as I wanted my kids to make individual creations, and that gets expensive on the school’s plasticine stores.

Starting with the blue, students roll out the clay to a uniform thickness. I had my students aim for about 1/2 to 3/4 of a cm. The blue is cut out to fill as much of the poster-board square as possible. These are the coastal waters. Another colour is rolled out and the lowest contour of the island is cut out and placed on the blue. Continue rolling out and cutting out the colours to create peaks on the island.

After the layers are in place, use a pencil or chopstick to gently angle each layer to that it slopes smoothly from level to level.

Students then place the graph paper beside their island and, looking down at the island from the top, draw the contour lines. They then colour their map according to the play-dough colours, adding in compass rose, legend, and title.

My students loved the hands-on aspect of this quick little project, and it did a very good job of illustrating the link between elevation and contour lines. 

Play-Dough Recipe

• 1 cup of flour
• 1/2 cup of salt
• 2 tsp cream of tartar
• 2 tbsp oil
• 1 cup water
• food colouring

Mix together in a pot and cook over medium-high heat, stirring constantly, until it coalesces into a single solid glob. (About 2 to 4 minutes.) Turn out onto counter and knead 3-4 times to form into ball. Store in air-tight container.