Which map feature uses lines to show relief by varying thickness, indicating slopes?

• A. Hachures
• B. Contours
• C. Isobars
• D. Shading

Answer: (A)

Lines that convey how steep terrain is by changing their weight and density are called hachures. On a map using this technique, short lines sit on the slope; the steeper the slope, the longer and more numerous (and often darker) the lines become. This visual cue creates a sense of relief by indicating direction and magnitude of slope right through line thickness and spacing. Historically, hachures were used before contour lines to show terrain, and they’re still a clear way to communicate slope on a map.

Contours, in contrast, are lines of equal elevation and convey relief mainly through how close or far apart the lines are, not through changing line thickness. Isobars are lines of equal atmospheric pressure, used in weather maps. Shading uses tonal changes to suggest elevation without relying on lines at all.