planimetric

Planimetric refers to representations, measurements, or data that relate to the plane of the Earth’s surface, disregarding elevation. In cartography, planimetric maps depict the horizontal positions of features such as roads, parcels, buildings, and watercourses while omitting relief information. Topography, in contrast, includes elevation and contours to convey the terrain’s shape.

Planimetric surveys determine x and y coordinates of features on a horizontal plane, using field surveys, GNSS in 2D mode, photogrammetry, or digitized planimetric data. The data are stored in planimetric coordinate systems, often in projected coordinates (for example, UTM) or geographic coordinates, depending on purpose. Planimetric accuracy concerns the precision of horizontal positions; vertical accuracy is not implied unless height data are added.

Applications include cadastral mapping, urban planning, transportation networks, and geographic information systems that require two-dimensional layouts. Planimetric maps are foundational layers for many GIS analyses and can be derived from aerial imagery or ground surveys; they are frequently published alongside orthophotos with vector planimetric features.

Limitations include the absence of height, slope, or terrain information. To represent three-dimensional reality, planimetric data are used with separate vertical data such as contours or digital elevation models.

Origin of the term derives from planus, meaning flat or level, and metric, indicating measurement. See also cartography, planimetry, topography, and GIS.