Cartogram

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cartogram

[′kärd·ə‚gram]
(mapping)
A type of single-factor or topical map that is often diagrammatic to show traffic flow, movement of people or goods, or value by area, where areas of the political subdivisions are distorted so that their size is proportional to their monetary value.

Cartogram

 

a map that shows the average intensity of a phenomenon for individual regions (units) of the territorial division shown on the map.

For example, a cartogram may characterize the average population density or the extent of plowed land (average hectares of arable land per hundred hectares of total land area) according to country, region, or district. To make the map easier to read, each territorial unit is colored or hachured according to the computed intensity of the phenomenon in it, so that the density of the coloring or hachures reflects this intensity.

Cartograms are especially widely used for graphic reproduction of statistical data on population and agriculture. A shortcoming of cartograms is that they do not show differences in the intensity of the phenomena within each territorial unit; this problem is lessened by a further territorial division.

References in periodicals archive ?
Dot maps, proportional symbol maps, choropleth maps and cartograms are between the most used ones.
The mapping was carried out on the basis of indicators of neonatal mortality (overall, early, and late) after a preliminary determination of average annual performance in individual medico-geographical regions, then the arithmetic mean (M) coefficients and standard deviation (sigma) were calculated, and on this basis a scale of levels of cartogram, grids with grouping mortality was defined.
Raisz, The rectangular statistical cartogram, Geographical Review, 24 (1934), 292-296.
(www.worldmapper.org), but Tyner's unusually straightforward, concise explanations of value-by-area and distance-by-time cartograms, including ones that are less often seen (such as linear and radial cartograms), are refreshing.
A cartogram is a map in which the size of a certain area - a city, say, or a county - is changed according to some specific measure.
Besides the conventional maps, O'Brien and Palmer used two area cartograms (anamorphoses) in order to map the different global religious allegiances and the Jewish Diaspora in the world.
Cartograms methods (anamorphosis) are very seldom implemented.
Using these methods, the cartograms are generated showing flows on a street network.
Other thematic mapping methods include proportional symbols, isarithmic, cartograms, and dot density.
Cartograms are easier to read, expanded maps provide additional coverage of key census variable and additions of graphs to maps showing important statistical information, trends over time and relationships between variables.