What is a contour line?

A contour line is defined as a line that connects points of equal elevation on a map. This concept is essential for understanding topography, as contour lines illustrate the shape and steepness of the land. On a topographic map, each line represents a specific elevation, and the spacing between these lines indicates the slope of the terrain—closely spaced lines suggest steep areas, while more widely spaced lines indicate gentle slopes. Recognizing contour lines helps in assessing drainage patterns, land development, and grading designs, all of which are critical in grading, drainage, and stormwater management.

The other options describe different features that are significant in land use and management but do not accurately represent the definition of a contour line.