1. Why might this map be useful?

4. Why might this map be useful?

5. Contour or Topographic Maps
Contour means “shape.”
Topography is the physical features of the land.
Ex: Mountains, Valleys, Cliffs, slope of the land.
Contour maps show the true shape of the land in a 2-D format.
Contour maps show elevations above sea level and surface features.

6. Contour Lines Contour Lines connect points of equal elevation.20
100
Contour Lines connect points of equal elevation.
Contour interval is the difference in elevation between two adjacent contour lines.
Every fifth contour line is an index contour and is darkened and numbered on the map.

7. What is the contour interval (in feet)?
ANSWER: 10 ft

8. Closed loop contours
Closed loop contour lines on a map show a hill (peak, mountain, etc.)

9. Slope of the Land:
Widely spaced contours show a gentle slope. Closely spaced contours show a steep slope.
Gentle slope
Steep slope
Which side of the hill has a steep slope?
Which side has a gentle slope?
West
East
Contour interval 100 ft.

10. Depressions- holes- are shown by closed loop contours with hachured marks inside them.
Barringer Crater, Arizona

11. Barringer Crater

12. Rivers Rivers always flow downstream.
Contour lines bend to form a “V” and point upstream.
Downstream
Upstream

14. Cliffs
Contour lines appear to run together representing a vertical slope.

15. Exact elevation
Benchmarks- tells us the exact elevation at a particular location.
Wherever you see this on a map, you will find a metal plate cemented to the ground at that location.
BM X 119
Exact elevation= 119 ft

17. Highest or Maximum Elevation
Locate the top of the mountain.
Find the contour interval.
Add the contour interval to the innermost circle (contour line)
Subtract 1 from this number to get the maximum value of the mountain or hill.
X_____
100
120
139
Highest possible elevation on this mountain is: _____
139 ft

18. 2. Latitude and longitude
3. Map scale ex: 1: 24,000

19. Hill in a hole

20. FEATURES ON A CONTOUR MAP
1. Latitude and Longitude
2. Scale (usually in miles and kilometers)
3. Man made structures (roads, parks, schools, etc)
4. Contour lines (show elevation)
5. Contour Interval
6. Benchmarks (exact elevation is measured)
7. Depressions (elevation drop)
8. Shoreline (elevation of zero)
9. Relief (difference between the highest and lowest points on map)
10. Gradient (closely spaced = steep; widely spaced = gentle)
11. Topographic Series (how much latitude the map covers)

21. COLORS ON A CONTOUR MAP
Sometimes there is a key for the colors on a specific map, otherwise use the following
a. Brown, or reddish brown- contour lines
b. Green, vegetation, parks, etc
c. Blue, some type of water
d. Black man made structures