Topography Training

drawing by Jon Gibson

Subject Areas:
Math, Science, Social Studies

Objectives:
The student will:

Time:
Two one-hour class periods

Materials:
Topography Training handout
Clay, play dough, or homemade recipe of dough
Ruler
Dental floss
Pencils
Card stock or poster board
Scissors

Must Know Info:

Topography Training is the first of three lesson plans designed to teach students about topography and to demonstrate the immense size of the Poverty Point site. Topography Training will allow students to create their own topographic map from a clay model after learning topography basics. The second lesson, Building a Mound for the Birds!, will result in the construction of a cardboard model of Mound A based on a topographic map of the site. A final activity is The Run for the Ridges in which students run a 50-yard dash and use the map scale to determine what this distance would be on the model.

A topographic map is a type of physical geography map which shows the elevation of the land by connecting points with the same elevation to form a line. These curvy lines are superimposed upon a two-dimensional map to give a three-dimensional view of the landscape. Students will be able to determine the height of the land as well as distances from east to west, etc.

Look carefully at the Mound A topographic map. Notice that there are elevation lines given for every five feet, beginning with an elevation of 100 feet. The highest elevation for the mound according to the map is 165 feet. These measurements do not indicate elevations above sea level. Notice that the caption for the map states that "the reference point was given an assumed elevation of 100 feet." This point became the "benchmark" for the surveyors. They simply measured the elevation above or below this arbitrary point. The elevation of the land around Mound A is 95 feet or lower.

Mound A is the tallest earthen structure at the Poverty Point site. This amazing mound is located along the western edge of the concentric rings of ridges and is thought by some to resemble a bird in flight. This is why some people call it the "Bird" Mound. It measures over 70 feet tall, 640 feet between the wing tips, and 710 feet from head to tail. Over 30 million basket loads of earth were needed to construct the mounds and ridges at the Poverty Point site. Each basket of soil would have weighed about 50 pounds. This adds up to a total of .75 million cubic yards of soil used to construct the mounds and ridges at the site.

Procedures:

1. Assign students to cooperative groups for the Topography Training. Have students analyze the student handout of the Mound A topographic map. Remind students that this is a kind of physical map called a topographic map. Determine prior knowledge by asking students what the curvy lines and numbers on the map mean. If necessary, explain that this kind of map depicts changes in elevation. The curvy line connects points on the map which are at the same elevation and the numbers tell the elevation.

2. Ask students to look carefully at the map of the "Bird" Mound and to share their observations. What lines on the map would support the idea that this mound was built in the shape of a bird? Where is the highest point on the mound located? Are the wings of the bird at a similar elevation? What about the tail?

3. Each group will begin an exploration of topographic mapping techniques by building a small mound from clay. Limit student building to a simple mound that resembles an upside down cone for this introductory activity. Students should save more complicated mountains for later.

4. Distribute a Topography Training handout to each cooperative group. Students will follow the directions to build their own mound and draw a topographic map of it.

5. After the topographic maps are completed, groups may reassemble their mounds and display these next to their maps. Remind students that their mounds will never be exactly the same after being cut up for mapping. The same thing holds true for archaeological excavations. Once the mound has been excavated, it can never be returned to exactly what it was before. This is why mounds are called "nonrenewable" resources. They can't be replaced.