Earth and Space Science / Unit 1: Earth as a System
1.6 Topographic Maps
Notes
A topographic map shows the shape of the land using contour lines, which connect points of equal elevation.
- The contour interval is the elevation difference between neighboring lines.
- Lines close together mean a steep slope; lines far apart mean a gentle slope.
- Closed circles show hills or peaks. Circles with tick marks (hachures) show depressions.
- Lines never cross (except a cliff) and V shapes point upstream where they cross a stream.
- Relief is the difference between the highest and lowest elevation in an area.
- Example: a peak at 1,250 m and a valley at 830 m give relief of $1250 - 830 = 420$ m.
Practice
Contour lines that are very close together indicate:
Elevation changes quickly over a short distance.
A map area has a highest point of 2,340 m and a lowest point of 1,680 m. Its relief is:
$2340 - 1680 = 660$ m.
Concentric closed contour lines with increasing numbers toward the center show:
Elevation rises toward the center.
Ready for more? Take the Unit 1 test.