Materials Included In Kit

Additional Materials Required

Safety Precautions

Remind students to wash their hands thoroughly with soap and water before leaving the laboratory.

Teacher Tips

• Enough materials are provided in this kit for 30 students working in pairs or for 15 groups of students.
• Make additional copies or laminate the Master Sheet for Foam Cutouts, Sample Topographic Maps, Common Topographic Map Symbols Sheets and Topographic Map Graph Sheets for future use.
• Students may wish to use their own actual topographical maps for Part II.
• Have students repeat Part II with another one of the Sample Topography Maps if time allows.
• As an extension, have students use actual topographic maps or create their own simulated topographical maps and repeat Part II.
• Have students compare and contrast topographic maps in an area that has undergone dramatic building development growth or geological changes.
• Topographic maps of any location in the United States may be accessed for free at http://terraserver-usa.com (last accessed April 2, 2009). Have students study the topography of the land in their home town or other areas of the United States using the images from this website.

Sample Data

Common Topographic Map Symbols Sheet

Answers to Questions

Part I

1. What features found on a topographic map may not be represented by an actual symbol?

   Minor streets and roads, street names, highway exit and entrance ramps, recent building developments and construction, private property, etc.

2. What other types of symbols not used in this activity are found on topographic maps? Sketch and label at least two examples.
   {12793_Answers_Figure_4}

Part II

3. What type of topography is indicated by contour lines that are very close together? By contour lines that are far apart? How do contour line spacing and contour line intervals compare?

   Contour lines that are very close together represent steep terrain and contour lines that are far apart represent relatively flat land areas. Small contour intervals occur in areas that are relatively flat and large contour intervals occur in steep regions.

4. Why do contour lines never intersect?

   Contour lines connect points that are at the same elevation. For example, a contour line that represents an area 200 feet above sea level will never cross a line that represents 100 feet above sea level.

5. In your own words, describe the terrain represented on the sample map.

   Answers will vary depending on the sample map.

6. Describe the terrain seen from Point A to Point B.

   Answers will vary depending on designated points A and B.

7. Which model has the gentlest slope?

   Model 3 has the gentlest slope.

8. How do the valley formations vary from Model 1 and Model 3?

   The valley formation of model 1 is much steeper than model 3. Model 3 has a larger distance between the contour lines in the valley area than model 1 and therefore has a more gradual slope.

9. Suppose a river is flowing through the valleys of Model 1 and Model 2. Which river would most likely flow more quickly? Why?

   The river in the valley of Model 2 will move more quickly than the river in Model 1 because the gradient of the valley seen in Model 2 is much steeper than Model 1.

10. Given that the contour interval for Model 1 is 50 feet and that the bottom foam layer of this model is at sea level, what would be the elevation of the top foam layer?

    Since there are 5 foam contour levels above the layer at sea level in Model 1, the elevation of the top foam contour layer would be 250 feet.

11. Where would you build a house on each of the three models? Explain why. Draw sketches if necessary.

    Student answers will vary. It would make the most sense to build a house on or near an area of low elevation change for each of the models, but some students may say that they would build a house near a steep area to obtain a better view!

Teacher Handouts

12793_Teacher1.pdf

Introduction

Obtain a basic understanding of common map symbols and learn topographic mapping skills using these simulated maps and models.

Concepts

• Topography
• Map symbols
• Contour lines
• Elevation

Background

Topographic maps are used by hikers, hunters, campers and geologists to determine the “lay of the land” or the locations of streams, hills, valleys and other geological features. The skills needed to understand and use topographic maps include the interpretation of symbols and special lines that are used to show the height of land above sea level. Topographic maps show three dimensions on a two-dimensional map using contour lines.

Contour lines are lines that connect points of equal elevation. Any point located along a specific contour line has the same elevation or height given by the contour line’s exact value. On topographic maps, contour lines are brown in color. Contour lines for relatively flat regions are far apart while the contour lines for steep areas are very close together.

A contour interval is the difference in elevation between two adjacent contour lines. Contour intervals vary in distance depending on the topography of the land. For example, a flat plain region may have a very small contour interval whereas a steep mountain slope may have a very large contour interval. Index contour lines are lines that are labeled with elevation.

Index contour lines appear on topographical maps as darker, thicker lines and are used as guides to determine the elevation value of adjacent contour lines. For example, if an index contour line is labeled as 150 feet above sea level and the contour interval of that map is 25 feet, the line just above that index contour line is 175 feet and the line just below is 125 feet.

Experiment Overview

The purpose of this three-part activity is to investigate and obtain a basic understanding of topography using simulated topography maps and models. The three parts to this lab include identifying common topographic map symbols, analyzing a topographic map and building a 3-D contour model.

Materials

Safety Precautions

Wash hands thoroughly with soap and water before leaving the laboratory. Follow all laboratory safety guidelines.

Procedure

Part I. Identifying Common Topographic Map Symbols

1. Obtain the Common Topographic Map Symbols Worksheet.
2. Using a textbook or the Internet for reference, fill-in the correct term for each symbol from the list on the worksheet below the correct symbol. Note: Each term will be used once.
3. Check the completed Common Topographic Map Symbols Worksheet with the instructor before continuing to Part II. 4. Answer the Questions for Part I.

Part II. Analyzing a Topographic Map

5. Obtain one of the Sample Topographic Maps. Record the letter of the map in the data table.
6. List the names of all the symbols found on the Sample Topographic Map in the data table.
7. Record the contour interval of the sample map in the data table.
8. Identify and circle an index contour value on the sample map. Record this value and note its general location on the map in the data table.
9. Identify and circle a steep hillside area on the sample map. Note its general location on the map and its minimum and maximum elevation levels in the data table.
10. Identify and circle a gentle sloping area on the sample map. Note its general location on the map and its minimum and maximum elevation levels in the data table.
11. Identify and circle a valley area on the sample map. Note its general location on the map and its minimum and maximum elevation levels in the data table.
12. Using a ruler, pick two areas that are 5 inches apart on the sample map. Label the first point A and the second point B.
13. Draw a line between these two points on the sample map.
14. A profile of the landscape along the line from point A to point B will now be created on the Topographic Map Graph Sheet. Measure and determine the horizontal scale from point A to point B in miles using a ruler and the Map Key on the sample map. Record the horizontal scale on the Topographic Map Graph Sheet.
15. Determine the vertical scale using the maximum and minimum elevations encountered when traveling from point A to point B on the map. Record the vertical scale on the Topographic Map Graph Sheet.
16. Following along the drawn line from Point A to Point B, for every ¼" plot the vertical and horizontal profile on the Topographical Map Graph Sheet. Note: It may be useful to write the elevation of each contour line that intersects the drawn line on the sample map before plotting the data on the Topographical Map Sheet. Indicate the locations of any special features or locations on the graph paper as well.
17. Answer the Questions for Part II.

Part III. Building 3-D Contour Models

18. Obtain three 8" x 5½" foam sheets of different colors, the Topographic Foam Master Sheet, a pen or pencil, and a pair of scissors.
19. Use the scissors to cut one of the 8" x 5½" sheets in half to obtain two 4" x 5½" sheets. Repeat this same cut for the other two pieces of foam. Six pieces will result.
20. Cut out the six shapes from the Master Sheet for Foam Cutouts.
21. Using the paper cutout pieces from step 19, trace the shapes onto the foam sheets using a pen or pencil. Note: Use different color pieces of foam for shapes that are numerically next to each other to provide color contrast.
22. Label each foam cutout with the appropriate number listed on each paper cutout.
23. Position the pieces as shown in Model Figure 1.
    {12793_Procedure_Model Figure_1}
24. Using the assembled 3-D contour model as a guide, identify an area of the model with a gentle slope and sketch this area in Part III of the data table. Do the same for an area with a steep slope and a valley.
25. Position the pieces as shown in Model Figure 2.
    {12793_Procedure_Model Figure_2}
26. Repeat step 24 for Model Figure 2.
27. Assemble the pieces as shown in Model Figure 1 once again (step 23).
28. Remove pieces 2, 4 and 6 from the 3-D contour model from step 27 (see Model Figure 3).
    {12793_Procedure_Model Figure_3}
29. Repeat step 24 for Model Figure 3.
30. Answer the Questions for Part III.

Student Worksheet PDF

12793_Student1.pdf