What Is the Purpose of Topographic Maps?

A topographic map is a special type of map that uses contour lines to represent areas of equal elevation. The distance between the contour lines represents a difference in elevation that is defined by the map's legend, and may be a specific number of feet, meters, miles, kilometers or any number of other measuring units. While most maps allow a person to measure distance between points, a topographic map allows a person to determine the height or depth of the terrain and the steepness of slopes.

Function

A topographic map represents a portion of the Earth's surface, and may include bodies of water such as the ocean floor as well as land surface.

Features

Topographic maps frequently include standard symbols to indicate the presence of major natural and man-made features such as roads, rivers, streams, lakes and buildings.

Identification

Topographic maps frequently make use of color (identified in the legend) to indicated certain features, such as green for vegetation and blue for rivers, streams and bodies of water.

Significance

Contour lines on U.S. Geological Survey (USGS) topographic maps are brown. The closer the lines are together, the steeper the slope (see Resources).

Fun Fact

Because the contour lines on a topographic map represent a line of equal elevation, these lines will never cross.

Resources

• USGS