Thematic map

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A thematic map
John Snow's cholera map about the cholera deaths in London in the 1840s, published 1854.

A thematic map is a kind of map. Different from normal maps, a thematic map is designed to show the distribution of human or natural features or data. The information may or may not be related to geography.[1] For example, a map which shows population is a thematic map.

Examples[change | edit source]

An early contributor to thematic mapping in England was the English astronomer Edmond Halley (1656–1742).[2] His first significant cartographic contribution was a star chart of the constellations of the Southern Hemisphere, published in 1686. In the same year he also published a map of the globe (Earth) in an article about trade winds. This map is sometimes called the first meteorological chart.[2]

Another example of early thematic mapping comes from London physician John Snow. Snow’s cholera map of 1854 is the best known example of using thematic maps for analysis of data. His method anticipates the principles of a geographic information system (GIS). He started with an accurate map of a London neighbourhood which included streets and water pump locations. Onto this Snow placed a dot for each cholera death. The pattern centered around one particular pump on Broad Street. At Snow’s request, the handle of the pump was removed, and new cholera cases ceased almost at once. Further investigation of the area revealed the Broad Street pump was near a cesspit under the home of the outbreak's first cholera victim.[3]

Reference[change | edit source]

  1. Bartz Petchenik, Barbara 1979. "From place to space: the psychological achievement of thematic mapping". Cartography and Geographic Information Science 6 (1): 5–12. http://www.ingentaconnect.com/content/cagis/cagis/1979/00000006/00000001/art00001.
  2. 2.0 2.1 Thrower, Norman J.W. 2008. Maps & civilization: cartography in culture and society. 3rd ed, University of Chicago Press. 97 ISBN 978-0-226-79974-2
  3. Robinson, Arthur H. 1982. Early thematic mapping in the history of cartography. University of Chicago Press. ISBN 978-0-226-72285-6