It is relatively easy to read elevation data, as long as you become familiar with a few of the key terms and rules. Highway construction

Elevation: In terms of land, this refers to the distance in relation to sea level. Contour lines: These invisible lines connect points of equal elevation to each other. They are essential to understanding elevation data. They show bands of elevation, as well as spot elevation on a map.

Hachures: Hachures are marks pointing downwards and are found on contour lines. These marks indicate a depression in elevation. The first rule is sometimes called the rule of V’s.