1. Introduction to Topographic Maps

2. Topographic Maps
Two dimensional model of the Earth’s surface (represents 3-D world)
Topographic maps are also known as contour maps.
Show elevation above sea level using contour lines.

6. “Real World”
Contour Map

7. Topographic Maps Contour Line –
- line on a map that connects points of EQUAL elevation.
- show elevation and shape of the land
Relief – Difference between high and low elevations

9. Topographic Maps Contour Interval –
difference in elevation between each line.
Contour interval =
20 feet
580
560
540
520

10. Topographic Maps Index Contour –
Usually every 5th line is printed darker and has an elevation printed on it.

12. Rules for Contours
Contour lines never cross

13. Rules for Contours
2. Contours form closed loops (even if not shown of the map.

14. Rules for Contours
3. Contours bend upstream (uphill) when crossing a stream.

15. Closely Spaced Contours
Steeper Slope (Gradient) – contour lines are closer together.

17. Wide Spaced Contours
Gradual/Gentle Slope (Gradient) – contour lines are farther apart.

19. A B

20. Depressions
Contour lines which show a depression, crater, or sinkhole on a map.
Shown by dashed lines (hachure marks) on the inside of a contour line
The elevation of the first depression contour is the same as the lowest regular contour near it.

21. 100
100 50

22. Let’s Practice!

25. Cookie Topography

26. Objectives
Students will use their knowledge of topographic maps and contour lines to construct a cross section diagram showing the changes in elevation represented by a cookie island.
They will also construct a model using topographic lines on paper.
Then they will label geographic features on their island map.
This activity helps students visualize what a topographic map represents and demonstrate their understanding of contour lines.