This week Statistics Switzerland has published the new thematic Atlas of Switzerland (in German and French). Every ten years since 1985 the Swiss Federal Statistical Office edits in cooperation with specialized cartographers a textual and visual anyalysis of the country’s status and of the changes in the last decades.
The 2006 edition uses cartograms (also called value-by-area maps, anamorphated images or simply spatial transformations) to illustrate changes. These cartograms are scaling the area in proportion to its population or other variables. More about cartograms in Cartogram central and Worldmapper.
The figure above shows the city of Zurich in three different cartographic representations, on the right hand the cartogram where the area ist transformed proportional to the areas population.
This is Switzerland without spatial transformation. The two maps show the amount and the evolution of flats in buildings (apartment houses or blocks of flats) with three and more flats. In 2000 in Switzerland 63% of all flats were in such apartment houses with a total of 56% of the population (!). An example: In 7 agglomerations (darkest green) more than 80 percent of all flats are in such apartment houses (see the left map, click on illustration to see full picture) :
And here is a spatial transformation of Switzerland showing the number of flats in apartment houses with three and more flats (averages by comunes, average for Switzerland is 7.4). Click to see full picture: