Introduction to Contour Maps

Name ______

INTRODUCTION TO CONTOUR MAPS

Introduction - Topographic or Contour maps are used to show elevations above sea level on a two dimensional map. Contour lines are Isolines that connect points of equal elevation. The spacing between contour lines indicates the slope; closely spaced contour lines indicate a steep slope whereas widely spaced contour lines indicate a gentle slope or flat area. A topographic profile is a cross-sectional view along a line drawn through a portion of a topographic map. It gives a more accurate picture of the shape of the land. Topographic maps are used to aid in the visualization of the shape of the land. Topographic maps include the accurate representation of places, directions, distances and elevations. People use topographic maps for things like planning a hike and purchasing a piece of property. In this exercise you will become familiar with simple contour maps and practice drawing profiles.

Vocabulary

Field Map -

Contour Line -

Contour Interval -

Gradient -

Elevation –

Sea Level -

Bench Mark -

Depression -

Profile -

Procedure - Study the contour maps and answer the questions that follow.

Here is a picture showing how the contour lines translate into shape of the land surface. The top drawing shows contours, the bottom drawing shows a profile (or cross section) of the land (hills and valleys). Note how the two drawings relate.

Map 1Elevations are measured in feet

1. What is the contour interval on this map? ______

2. What is the highest possible elevation? ______

3. What is the elevation of point A? ______

4. Measure the distance, from Point A to Point B using the map Scale. ______

5. Measure the distance, from Point C to Point D using the map Scale. ______

6. Determine the elevation at Point C: ______and Point D: ______

Calculate the Difference (D-C): ______

7. Calculate the elevation gradient between Point C and Point D: ______

* gradient = difference in field values ÷ distance between points ** UNITS**

8. Draw a profile that describes the elevation across line A-B.

A B

Map 2

A

C

E

B

D

Contour interval: 20 feet

9. What is the contour interval on this map? ______

10.What is the elevation at point A? ______

11. What is the highest possible elevation for the top of Amethyst Hill? ______

12. Calculate the gradient from A to B. ______

13. Calculate the gradient from C o D. ______

14. In which direction does Deep River flow? ______

15. Explain how you know the direction Deep River is flowing. ______

______

16. Draw a profile that describes the elevation across line A-E.

A E

17. Which letter is located on the steepest slope? _____ .

18. How do you know this is the steepest slope? ______

19. How does a contour map indicate a steep gradient?

20. How does a contour map indicate a flat area (low gradient)?

21. What are two ways you can determine the direction of stream flow from a contour map?

22. Do all rivers flow to the south? Explain your reasoning in terms of elevation.

23. How are depressions shown on a contour map? Draw a picture.

24. What are contour maps used for?