English

Noun

1. Generally, a map used to indicate geographically-bound statistical information, typically region-by-region values of a given variable, for example by using different shadings for different ranges of values.
   • 1888 October, Dewey, Davis R., "Elementary Notes on Graphic Statistics", in the Massachusetts Institute of Technology Technology Quarterly, Volume II Number 1, published by the students (1888–1889), p. 99,

     […] whether, however, two states with these respective ratios do not consequently sufficiently differ […] as to warrant distinction in the cartogram, is open to question.

   • 1895, "Book Notes", in Academy of Political Science (U.S.) and Columbia University Faculty of Political Science, Political Science Quarterly, Volume X Number 3, Academy of Political Science (1895), p. 560,

     The fifth cartogram illustrates the criminal statistics for the period 1882-91, which are of unusual interest because […]

2. Specifically, a map-like graph where the relative areas of graph regions are proportional not to the relative areas of the land regions they represent, but rather to another quantitative variable, such as population or gross domestic product.

Synonyms

• A map-like chart: area cartogram, isodemographic map (when the variable used is population), value-by-area map

References

• Gillard, Quentin. "Places in the News: The Use of Cartograms in Introductory Geography Courses." Journal of Geography. 78 (1979): 114-115.

A cartogram is a map in which area is not preserved. Instead, another thematic mapping variable like travel time or Gross National Product is substituted for land area. The geometry or space of the map is distorted in order to convey the information of this alternate variable. There are two main types of cartograms: area and distance cartograms.

An area cartogram is sometimes referred to as a value-by-area map or an isodemographic map, the latter particularly for a population cartogram, which illustrates the relative sizes of the populations of the countries of the world by scaling the area of each country in proportion to its population; the shape and relative location of each country is retained to as large an extent as possible, but inevitably a large amount of distortion results. Other synonyms in use are anamorphic map and density-equalizing map. The German word for cartogram is Kartenanamorphote, not Kartogramm.

A distance cartogram may also be called a central-point cartogram. This form is typically used to show relative travel times and directions from vertices in a network.

One of the first cartographers to generate cartograms with the aid of computer visualisation was Vladimir S. Tikunov of Moscow State University in the 1990s. He called them anamorphosises.

References

Further reading

• Campbell, John. Map Use and Analysis. New York: McGraw-Hill, 2001.
• Gillard, Quentin. "Places in the News: The Use of Cartograms in Introductory Geography Courses." Journal of Geography. 78 (1979): 114-115.
• Tobler, Waldo. "Thirty-Five Years of Computer Cartograms." Annals of the Association of American Geographers. 94 (2004): 58-73.
• Vescovo, Victor. "The Atlas of World Statistics." Dallas: Caladan Press, 2005.

External links

• Cartogram Central
• Multiple cartograms showing the results of the 2004 US Presidential Election
• Worldmapper collection of world cartograms