1. Topography Our most exciting unit !!

2. What is topography? The shape of the land determined by elevation, relief and landforms. What is elevation?

3. Topography Elevation is the height above sea level.

4. What does sea level mean?

5. Topography Relief is the difference in elevation between the lowest and highest parts of an area. What are some landforms?

6. Topography A landform is a feature formed by earth processes. List 3 examples of landforms.

7. Topographic Maps Scientists (specifically geologist and cartographers) have designed maps which are called topographic maps. What type of items do you think are found on these maps?

8. A topographic map is a special kind of map that provides 3 dimensional information in a drawing. Natural structures like mountains, valleys, plains, lakes, and rivers are shown on a topographic map. You will also find manmade structures like roads, boundaries, radio towers, and major buildings Topographic maps are used by engineers as they look for coal, oil, and gas. They can be used to plan residential and commercial buildings. And they are used by the military and for recreational purposes like hiking and camping.

9. What is a Topographic Map? In contrast to most maps, a topographic map shows the shape of the Earth’s surface by using contour lines.

10. Contours are imaginary lines that join points of equal elevation above or below sea level.

11. Topographic Maps Contour interval – change in elevation between contour lines. Contour Interval is 10 m. M M M

12. Reading a topographic map- Index Contours A index contour is a contour line that is accentuated in thickness and is labeled with the appropriate measure of elevation. Index contours occur every fifth contour line. Help the map user read elevations on a map. Red arrows indicate location of index contours.

13. How to read a topographic map

14. Notice the two high points on the island. What is the elevation of the two high points?

15. Point A sits right on the 0 m contour line. Since all points on this line have an elevation of 0 m, the elevation of point A is zero. What is the elevation of Point A? Contour internal 10 m

16. Point B sits right on the 10 m contour line. Since all points on this line have an elevation of 10 m, the elevation of point B is 10 m. What is the elevation of Point B? Contour internal 10 m

17. Point C does not sit directly on a contour line so we can not determine the elevation precisely. We do know that point C is between the 10m and 20 m contour lines so its elevation must be greater than 10 m and less than 20 m. Because point C is midway between these contour lines we can estimate the elevation is about 15 meters (Note this assumes that the slope is constant between the two contour lines, this may not be the case). What is the elevation of Point C? Contour internal 10 m

18. Reading or interpreting a topographic map 1. Familiarize yourself with the maps symbols and keys. 2. Look at the contour lines – if the lines are very close together, this would indicate the area is ___________. 3. If the contour lines are far apart, the area is ____________. flat steep

19. Notice how the contour lines are used to show how gentle or steep the slope is.

20. Topographic Maps Now for the fun part You will be given a topographic map. Follow the directions on the worksheets. Enjoy!!! Topographic Maps