Topography is the shape of land and includes area’s elevation, relief, and landforms. Elevation is the height above sea level of a point on Earth’s surface. Relief is the difference in elevation between the highest and lowest parts of an area.

A topographic map shows surface features of an area. They provide accurate information on the elevation, relief, and slope of the ground.

Contour lines, sometimes called "level lines," connect points of equal elevation. Contour lines show elevation, relief, and slope on topographic maps.

The contour lines are usually marked to show their elevation. The change of elevation from one contour line to the next is called the “contour interval”.

Every 5 th contour line is called “Index Contour Lines”. Not every line has to be marked, mapmakers begin counting at the “bold” contour line to find elevation.

Closely space = steep slopes Widely space = gentle slopes or flat areas Closed loop with no other contour line = hilltop Closed loop with dashes = “depression” or hollow in ground

The shape of contour lines helps to show ridges and valleys. V-shaped contour line pointing downhill = ridge line V-shape contour line pointing uphill = valley A stream flows toward the open end of the V-shape

Topographic Map