HGA | Anasazi

Geography Standards:

Standard 1: How to use maps and other geographic representations, tool and technologies to acquire, process, and report information from a spatial perspective.

Purpose:
To understand and interpret topographic map.

Materials:

• 5-6 pounds of clay for each group of 3-5 people
• 1 packet to include the following for each group:
  • ruler
  • clay cutter
  • 3-5 skewers
  • pencil
  • scissors
  • 6-8 sheets of recycled unlined paper
  • 8X11 cardboard
• Pictures of various landforms (displayed)
• Various topographic maps

Background Information:
Topographic maps have wiggly lines all over them called "contour lines". All points on a contour line have the same elevation. Elevation is a work we use to describe how high something is above the level of the sea. Think of the sea as having an elevation of "zero", so all the land features will have an elevation, or height above sea level. For example if a contour line on a topographic map represents an elevation of 100 feet above sea level, it means that wherever that line wanders on the map has a 100 foot elevation. If you started at a point that was 10 feet above sea level and walked along a hill in such a way that you never went either up hill or downhill, you would be walking the 100 fool topo line for that hill.

The spaces between the lines are called "contour intervals". On the United States Geologic Survey (USGS) 7.5 minute maps, the contour intervals between each topo line represent 80 vertical feet. If the lines are close together, it means that you would not have to travel far to go up 80 feet in height. You would be going up a very steep hill. Tall cliffs show up on a topo map as lines that are so close together that they seem to be all stacked up on top of each other. When the lines are far apart, it mean that you have to travel a much longer distance to gain that same 80 feet in height. You would be on land with a very slight slope. Wide gentle valleys and plains will show up on a topo map with wide spaces between the lines. (From Ridges to Rivers: Watershed Exploration)

Procedure:
Pre-Activity
Discuss the uses of topographic maps.

Demonstration: (Workshop Photos)

1. With clay, build a island. Stay within the 8x11 cardboard. Try to make your island at 3 inches or higher at the highest point. Create interesting landforms (craters, valleys, etch)
2. Cut clay into several layers. Measuring is not necessary for the demonstration.
3. Place each layer on one sheet of paper and trace.
4. Cut each traced shape. (Demonstrate with one only)
5. Arrange each cut piece to match your island.
6. You have created a topographic map,

Questions to consider: (Chart paper)

• How will you measure the layers so the intervals are equal?
• How detailed do you want your topo map to be?
• How will you know how to align the pieces of paper, once you cut them?

Directions: (Chart paper)

1. Build a landform
2. Cut the clay at equal intervals
3. Trace the pieces on a sheet of paper and cut it.
4. Assemble cut pieces of paper to create your topo map
5. After making you map, compare you map with actual topographic maps. See if you can find similar geographic features.

Distribute materials

Post-Activity Discussion:

• How did your topographic map compare with your clay landform?
• How did the thickness of the layers affect your topo map?
• If you were going hiking, how would you use a topo map to plan your route?

Bibliography:
"From Ridges to Rivers: Watershed Explorations"
Developed by the San Luis Obispo County, California 4-H Youth Development Program