Topography!Topography!

Understanding topographic maps.

What is a topographic map?

Topographic maps show the topography of a land area.– When Earth Scientists

refer to the lands’ topography, they are talking about its surface features.

Topographic maps show the elevation of various land features.

Both natural and artificial land features are displayed (rivers and buildings for example).

An example…

Map features

To show elevation, lines around the map are used for various boundaries. These are called contour lines.

To determine how big of a contour interval, or how much real life elevation is indicated by each contour line, the cartographer bases this on the relief of the land.This contour map uses color to show

contour lines. Can you tell what the contour interval is?

Features continued…

Topographic maps, like most, also have a scale usually written in a ratio (1:24,000 means 1 inch = 24,000 inches, or 2,000 feet).

Every fifth contour is labeled to avoid cluttering the map with elevations.

Topographic maps also have legends, but buildings are usually included in the legend as well.

Interpretation

You can figure out how steep a land area is by studying a contour map of the area.

Steep, sharp cliffs are indicated by very close contour lines.

Flat, broad areas are indicated by spaced out contour lines.

Be sure to note the contour interval – if its small, it may not be as steep as you think! (The same is true for large contour intervals – the land may not be as flat as you think!).