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. In other words, 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 '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' or 'density-equalizing map'
[1][2]. The German word for cartogram is ''Kartenanamorphote'', and not ''Kartogramm''
[3]
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.
Bibliography
★ 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
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