Chorochromatic map

For broader coverage of this topic, see Thematic map.
Picture of the U.S. state of Georgia divided up and colored by geologic feature.
USGS geological map of Georgia that visualizes distinctive geological regions as unique colors. Note that the regions change based on variations in rock type, not preexisting political boundaries.

A Chorochromatic map (from Greek χώρα chóra 'region' and χρώμα chróma 'color'), also known as an area-class, qualitative area, or mosaic map, is a type of thematic map that portray regions of categorical or nominal data using variations in color symbols. Chorochromatic maps are typically used to represent discrete fields, also known as categorical coverages. Chorochromatic maps differ from choropleth maps in that chorochromatic maps are mapped according to data-driven boundaries instead of trying to make the data fit within existing, sometimes arbitrary units such as political boundaries.[1]

  1. ^ Kraak, Menno-Jan; Ormeling, Ferjan (2003). Cartography: Visualization of Geospatial Data (2nd ed.). Harlow, England: Prentice Hall. p. 129. ISBN 978-0130888907.