A contour interval is the vertical distance or difference in elevation between contour lines. Index contours are bold or thicker lines that appear at every fifth contour line. If the numbers associated with specific contour lines are increasing, the elevation of the terrain is also increasing.
What is the contour interval of a map?
Individual contour lines on a topographical map are a fixed interval of elevation apart known as a contour interval. Common contour intervals are 5, 10, 20, 40, 80, or 100 feet. The actual contour interval of a map depends upon the topography being represented as well as the scale of the map.
What types of contour intervals are there?
There are 3 kinds of contour lines you'll see on a map: intermediate, index, and supplementary.
- Index lines are the thickest contour lines and are usually labeled with a number at one point along the line. ...
- Intermediate lines are the thinner, more common, lines between the index lines.
