Cartographic map design
Lorenz Hurni

Institute of Cartography ¦ Institut für Kartographie
ETH Hoenggerberg ¦ ETH Hönggerberg
CH-8093 Zurich ¦ CH-8093 Zürich
Switzerland ¦ Schweiz


According to the definition of the International Cartographic Association ICA (www.icaci.org), "a map is a symbolised image of geographical reality, representing selected features or characteristics, resulting from the creative effort of its author's execution of choices, and is designed for use when spatial relationships are of primary relevance. Cartography is the discipline dealing with the conception, production, dissemination and study of maps." The German philosopher Jürgen Mittelstrass also describes one of the major tasks of cartography, although his text is not specifically directed to cartographers: "The differences between information, opinion and knowledge are becoming less and less clear, especially with mass media.
Though modern information technologies like Internet offer an almost complete encyclopaedia, this wealth of unprocessed information can by no means be considered knowledge. The selection and processing based on thematic competence which characterise knowledge and which enable understanding are missing." In order to fulfill this goal two principles are of paramount importance in cartography: Generalisation and symbolisation.

There are several process included in generalisation. The first step, however, is always the selection of the information to be communicated by the map. Then, it is time to group the generalisation manipulations to be performed on the selected data into two main types:

ICA defines the following generalisation operators: Selection, Simplification, Omission, Smoothing, Displacement, Aggregation, Classification, Symbolisation, Exaggeration.

Symbolisation means to assign to a geometric object a specific graphic appearance, like for instance line width, line style or colour.

Both generalisation and symbolisation processes are closely connected since changing an objects appearance will have an influence on the element geometry and vice versa. In order to draw a graphically proper map, the sum of numerous individual graphic adjustments make up the overall readability.
In general, and especially with detailed topographical maps such as orienteering maps - map makers tend to put too much information in their products, filling up the limited space. To follow the rule "less is more" can be recommended in almost all map projects.


The presentation in PDF file (2.4 MB)