Map Compiling, Map Reading, and Cartographic Design in “Pragmatic Pyramid of Thematic Mapping”
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QUAESTIONES GEOGRAPHICAE 29/1 • 2010 MAP COMPILING, MAP READING, AND CARTOGRAPHIC DESIGN IN “PRAGMATIC PYRAMID OF THEMATIC MAPPING” BEATA MEDYŃSKA-GULIJ Adam Mickiewicz University, Institute of Physical Geography and Environmental Planning, Department of Cartography and Geomatics, Poznań, Poland Manuscript received January 21, 2010 Revised version March 12, 2010 MEDYŃSKA-GULIJ B., 2010. Map compiling, map reading and cartographic design in “Pragmatic pyramid of thematic mapping”. Quaestiones Geographicae 29(1), Adam Mickiewicz University Press, Poznań 2010, pp. 57-63, Figs 5. ISBN 978-83-232-2136. ISSN 0137-477X. DOI: 10.2478/v10117-010-0006-5. ABSTRACT. This paper concerns the dependent relationships between map compilation, map reading, and carto- graphic design with special regard to thematic mapping. The fi rst step is to measure the simple relationship be- tween cartographic practice and map design and present a pyramid of pragmatic thematic mapping. The model contains various types of maps, a range of cartographic principles, and sources of knowledge for map design. When presented as a pyramid, these functional dependencies can refer to a series of pragmatic criteria which relate to the use of thematic maps. KEYWORDS: pragmatic cartography, thematic mapping, cartographic design. Beata Medyńska-Gulij, Institute of Physical Geography and Environmental Planning, Adam Mickiewicz University, Dzięgielowa 27, 61-680 Poznań, Poland, e-mail: [email protected] Introdution example by cartographic compilation. Most often, map compilation results in the creation of themat- Pragmatic cartography may be understood ic maps. These represent the distribution of one both in the sense of practical and in a more lim- particular phenomenon, though a thematic map ited way pertaining to semiotics. According to needs topographic information as a basis (Kraak Morris (1971), the pragmatic is the relationship & Ormeling, 2003). Thematic maps have topi- between the sign and the interpreter, and, in par- cal contents which are graphically-emphasized ticular, the problem of how the intended desig- or highlighted over a basis which has a status of nation is understood by the perceiver. Freitag ‘ground’. According to Dent (1990), thematic map (1971) associates the research area of pragmatic compilation refers to the construction of a special- cartography with the map’s function as a vehicle purpose map from a variety of previously exist- of information. ing sources: base maps, other thematic maps, or Pragmatic cartography is connected fi rst and both, and it involves numerous steps. foremost with map reading. With various meth- This paper on thematic mapping concerns ods of using digital maps, the relationship be- the inter-relationship between map compila- tween map and user has broadened its scope, for tion, map reading, and cartographic design. It 58 BEATA MEDYŃSKA-GULIJ presents a measurement of the relationship be- to Dent (1999), no one best way to a design so- tween pragmatic cartography and map design, lution can be predetermined for all maps – only resulting in a pyramid of pragmatic cartography principles and general approaches can guide the for thematic mapping. The model contains many cartographer. Design characteristics of successful types of maps, a range cartographic principles, maps include clear, legible, attractive, easy to use, and sources of knowledge for map design. The accurate (Southworth & Southworth, 1982) are in- functional dependencies in these inter-relation- exact and therefore inexplicable and unclear for ships will reveal pragmatic criteria for the use of map-makers such GIS users. thematic maps. The measurable parameter of map design is the number of designed symbols on the map. The number of symbols directly infl uences the Methodology ease of preparation of an effective map and also map reading. The greater the number of symbols, The study was carried out in the following the more diffi cult it becomes to organize them stages. visually in the reading process. The number of Thematic mapping includes the following: designed symbols determines the method and • a choice of two aspects of pragmatic car- number of graphical variables used (Bertin, 1983) tography: map compilation and map reading and so the more symbols there are to be defi ned, • a choice two measurable parameters on the more complicated the graphic design stage the thematic map: the number of designed sym- becomes. bols on the map and theme:base ratio on the the- The second measurable parameter on the matic map thematic map is theme-base proportions. Fol- • include the dependence in the graphic lowing Slocum et al. (2005), thematic symbols model – the main wall of pyramid directly represent a map’s theme, and should • refer these dependences to types of maps, stand out. They are often used in conjunction adaptation of cartographic principles, and sourc- with base information in the mapped area. One es of knowledge for map design of the basic parameters adopted for developing • refer pyramid dependences to the prag- thematic maps is the proportion between the the- matic criteria of thematic map use. matic content and the base content. Three main Vector databases allow the GIS-user to make variants of the relationship exist: the predomi- maps individually, which in fact constitutes car- nance of thematic content over base content, a tographic compilation. Compilation relates to the state of equilibrium between thematic and base connection of vectors in a layered structure, with contents, and the predominance of base content the subsequent subjection of elements (point, line (Fig. 1). and area) to the process of graphical design. In this study the fi rst aspect of pragmatic cartogra- phy will be connected with cartographic compi- lation: the limit of preparation of cartographic compilation by the GIS-user (non-cartographer). The second aspect of pragmatic cartography will be connected with comprehension, i.e. map read- ing. In this case, it will concern the limit of map reading without specialized training, namely, Fig. 1. Proportions of the thematic content to base content on a thematic map maps designed for the general user versus those designed for specialists. The division into more and less important as- Pragmatic cartography is dependent, in part, pects streamlines the method of graphical design on effective cartographic design comprised of of thematic maps. A visual reinforcement of the many aspects, e.g. appropriate choice and imple- theme with respect to the base gains key impor- mentation of map elements, visual hierarchy, con- tance in the cartographic design of thematic maps. trast, and balance (Slocum et al., 2005). According The topical contents contain the main elements MAP COMPILING, MAP READING, AND CARTOGRAPHIC DESIGN IM “PRAGMATIC PYRAMID OF THEMATIC MAPPING” 59 which form the basic contents of the map and Results should be located at the highest (fi rst) reading lev- el. The base contents, considered as supplemen- Fig. 3 presents a view of the pyramid of the- tary (referential), should be visually weakened to matic mapping comprising four walls above, such an extent that their elements ought to be situ- which are set forward in detail. All of the walls ated at the lower (second) level of map reading. may be considered as vertical according to three steps, that is, according to the number of sym- bols. In turn, the main wall and the map types wall may also be interpreted horizontally accord- ing to three columns, according to the theme-base relationship. Fig. 3 presents the main wall of the pyramid, which contains the three theme-base relations on the thematic map mentioned above. In turn, the horizontal steps are three variants of the number of symbols designed on the map. The pinnacle of the pyramid is not sharp, but bevelled, for the minimum number of symbols to be designed on the thematic map is 2 (for balance 1=1) or 3 (2>1, 1<2). The maximum number of designed sym- bols is the greatest possible number of symbols located on one thematic map, i.e. ones that can be read. Between the upper and the middle steps of the pyramid there is the limit of preparation and cartographic compilation by the GIS-user. The long limit between the middle and lower steps of the pyramid is the limit of map reading without specialist training (Fig. 3). The ability of reading the map in the lower step of the pyramid requires professional knowledge and practice. Fig. 2. Legend of the thematic map in three variants of pro- The map types wall presented in Figure 4 portions of the theme to the base shows examples of thematic maps, whereas in Fig. 2 fragments show of the appropriate car- In the vertical legend of the map in Fig. 2, tographic images. At the highest step there are symbols are placed in accordance with their hi- cartographic compilations; a fragment of the erarchy: symbols related to the theme are located multivariate symbol map in three variants of the higher, while those related to the base are lower. theme-base relation (Fig. 4). In the fi rst column, one can see the predominance On the middle step there are maps published of the theme (9>5); in the second a state of equilib- in school atlases: in the left column an economic rium (9=9); while in the third, the predominance map, in the middle column a map of power in- of signature numbers in the base (9<14). On the dustry, and in the right column a map of land- map containing symbols on the left of the legend scape. On the lower step there are the following (Fig. 2), the theme is highlighted in relation to the examples of thematic maps: in the left column, a smaller number of symbols in the base. In turn, geological map with a reduced topographic base; in the right legend there are fewer symbols con- in the middle column, a tourist map; while in the nected with the theme, but it is possible to refer- right column, a sozological map with complete ence their location to the topographical contents topographic contents.