Word of the Day:

: to denote surfaces in relief (as on a map) by shading with short lines drawn in the direction of slope

"Topographic surveys were done for the first time with compasses…. And mapmakers developed new methods for depicting terrain. One method, called hachuring, used lines to indicate the direction and steepness of a slope." — Greg Miller, National Geographic, 16 Sept. 2016

"Lava flows that filled in much of the Yellowstone caldera are shown in this geologic map of the Yellowstone-Teton region. Rock units are colored by age and composition. Boundaries of the Yellowstone and Island Park calderas are hachured." — Robert B. Smith and Lee J. Siegel, Windows into the Earth: The Geologic Story of Yellowstone and Grand Teton National Parks, 2000

Hachuring is an old map-drawing technique that was largely replaced in later years by the use of contour lines, or lines that connect points of similar elevation. The word hachure, which can also be a noun referring to one of the short lines used in hachuring, comes from the French hacher, meaning "to chop up" or "hash." This French word is also the source of the verbs hash, which can mean "to chop (food, such as meat and potatoes) into small pieces," among other meanings, and hatch, meaning "to inlay with narrow bands of distinguishable material" and "to mark (something, such as a drawing or engraving) with fine closely spaced lines."