Topography

The Art of Reading &Using Contour Maps

What is a Topographic Map?Earth's surface shape shown by contour linesContour lines - lines connecting points of equal elevationmeasure mountain height, ocean depths, slope steepnessAllows planning for –

parkshiking/ridingbuilding/constructiondrainage

Reading Topographic MapsContours – lines of different widthsContours never crossUsed to determine elevations – index contours are widerElevations printed along index contoursNarrower contours found between index contours – help show more details of land surface

Contours close together = steep slopesWidely spaced contours = fairly level/flat ground slope relatively levelcontour interval = elevation difference between adjacent contour lines

Reading Topographic Maps (continued)

Index Contour (Elevation = 100’)Index Contour (Elevation = 200’)

Every 5 lines: (200-100)/5 = 20’Therefore, contour interval = 20’

What Does It All Mean?The more contour lines packed closely together represent steep, cliff-like areas

What Does It All Mean?The more two contour lines are spread apart, the flatter the area

What Does It All Mean?Contour lines that form a mountain-like shape show where water has cut a path (valley)

• What is the contour interval?

• What is the elevation of Mt. Rainer?

• Describe the circled area.

• Describe this circled area.

14,000

13,800

14,000 – 13,800 = 200200 / 5 lines = 40’

X

What is the average elevations for houses 3, 4, and 5 to the nearest tenth of a meter?

Contour Interval

= 3 m

112

.

9 7 3

82

.

..

PredictionsHow might this area’s landform change over time?

Remember…Topographic maps can help you find elevations, Trails, and Places to climbTopographic maps show you the “lay of the land” (landforms) by connecting points of equal elevationIndex contour lines are darker and have an elevation associated with itThe ‘Contour Interval’ is the elevation distance between two adjacent linesScales are usually shown in inches or feet

Mt. Capulin Capulin Volcano National Monument, located in northeastern New Mexico, was designated a U.S. National Monument on August 9, 1916.

It is a well-preserved, relatively young (58,000 to 62,000 years old), symmetrical cinder cone. It rises steeply from the surrounding grassland plains to an elevation of 8,182 feet above sea level. The irregular rim of the crater is about a mile in circumference and the crater about 400 feet deep.