1. A topographic map is a map that shows the shape (topography)of the land.

2. Topographic Map Vocabulary
Each contour line represents lines of equal elevation
The space between contour lines is called the contour interval
Every fifth line is called an index contour with the number of feet of elevation
Little lines that intersect contour lines are called “hachures”

3. Rules for Topographic Maps
Two contour lines never cross each other
Contours make a “V” shape as they cross streams, “v’s” point upstream
The closer the contour lines are, the steeper the slope is
Closed contours (circles inside each other) represent hills
All contour lines close eventually even if it’s off the map
Hachure marks represent depressions

4. Finding the map’s location on Earth
Latitude –horizontal lines
show distance north or
south from equator
Longitude – vertical lines
show distance east or
west from prime meridian
Together, they form a grid of Earth’s surface

5. How latitude/longitude is divided
Latitude –horizontal lines show distance north or south from equator
Divided into degrees, minutes, seconds
1 degree = 60 minutes
1 minute = 60 seconds
ex. N 45° 30’ 30”
Longitude – vertical lines show distance east or west from prime meridian
Degrees, minutes, seconds like latitude
ex. W 124° 30’ 45”

6. Map Scales Verbal – scale is stated with sentence ex. 1 inch=4 miles
Graphic- image on map
Fractional- can be any unit
ex. 1:24,000 means:
every cm on map equals 24,000 cms in actual distance OR
2. every inch on map equals 24,000 inches in actual distance

7. Gradient of a river or slope (how steep it is)
Difference in elevation (rise)
divided by
Distance on map (run)
written as ft/mi
Example: the Willamette River is 410 ft elevation at its head and 10 ft at its mouth. It flows apprx. 100 miles. What is its gradient?
410 ft -10 ft =400 ft
400 ft ÷100 mi = 4 ft/mi

8. Using the Metric System
The METER is the basic unit for length
1/1000 m = 1 mm
1/100 m = 1 cm
1/10m = decimeter
Meter
1m x 10=decameter
1m x 100 = hectometer
1 m x 1000 = kilometer
To convert from cm to km, just move the decimal point 5 places to the left
453,200 cm = 4.5 km