hachure
Hachure is a map shading technique in which relief is represented by short, straight lines known as hachures. The lines are typically arranged in a regular pattern and are oriented roughly perpendicular to the contours, following the slope of the terrain. The density, length, and sometimes angle of the lines convey the steepness and texture of the landscape: steeper areas receive more or longer lines, while gentler slopes have fewer lines. Hachures are commonly used to indicate elevation and relief in lieu of filled shading or contour lines, especially on early or wood-engraved maps where detailed shading was difficult to achieve.
History and usage: The technique emerged in early modern cartography and was widely used in European maps
Etymology and scope: The term comes from the French hachure, from hacher meaning to hash or chop,