What are Contour Lines?

Contour lines are lines on a map that connect points of equal elevation or altitude above a reference datum, such as sea level. They are used to represent the three-dimensional shape and features of the land surface in a two-dimensional map. Contour lines are usually drawn at regular intervals, with each line representing a specific elevation above the reference datum.

Contour lines can be used to determine the slope and steepness of a terrain, as well as to identify landforms such as ridges, valleys, and hills. By examining the spacing and direction of the contour lines, it is possible to determine the shape and gradient of the land surface.

The closer the contour lines are to each other, the steeper the slope. Conversely, the farther apart the contour lines, the flatter the terrain. A closed contour line, such as a circle or oval, represents a hill or summit, while a series of contour lines closely spaced and forming a "V" shape represent a valley.

Contour lines are an important tool in cartography and are used in various applications, including surveying, engineering, and outdoor recreation. They are often found on topographic maps, which show the shape and features of the land surface, including elevation and relief.