7 Cartographic Design
Maps are designed to communicate themes, reveal patterns, and store information. Achieving these goals relies on design principles that are both general and specific. Specific design decisions include composing a title, choosing a projection, map scale, spatial extent, classification scheme, and sharing references to data and sources. General design decisions include selecting colour schemes and typefaces for text and laying out the geographic space to be mapped and non-map elements (title, legend, north arrow, scale, etc.).
Map Elements
The following map elements are LOOSELY ordered based on the extent to which they are required, thematically essential, or optional. In selecting and applying each element, as with all decisions regarding map layout and design, decisions should made based on their service to the map’s objective.
Title: maps need titles, even a reference map. The map should pithily convey the maps theme and not overlap in content with the title of the legend. If the title “needs to be long,” this is an opportunity to consider how the title can be split between the Title and the Legend Title.
Legend: communicating the symbology of the map is accomplished via the legend. Legend content should be determined by the map, not the constraints on the legend’s position, size, orientation, etc. As a rule of thumb, the title of the legend should focus on the content of the legend as it supports the map’s theme. The worst title for a legend is “legend.”
Neatline: the line surrounding the geographic extent of the geographic space being mapped. Nothing geographic falls outside the neatline, but other elements can be placed within, outside, or straddling the neatline (legend, scale, title, north arrow, etc.)
Scale: expressing the spatial relationship between the mapped space and that space’s extent in reality can be done in several ways. Like Orientation below, at very small scales, it can be hard to decide how to express scale (since the scale is often different for different parts of small scale maps). Scale can be expressed numerically as a ratio (1:50,000), “verbally” (1cm = 10km), or with a scale bar. Scale bars are elegant in their ability to communicate the scale of the map under conditions of zooming (if the final map is printed and expanded the two maps have different scales).
Orientation (North Arrow): not all maps need to have their orientation specified. Generally, as map scale decreases the need to communicate orientation (where is north) decreases. When the geography being portrayed communicates orientation, a north arrow, or other orientation information, is less necessary. Continental and world maps are good examples of maps that don’t need orientation information, in fact for small scale maps north arrows can be confusing. Place of a single north arrow might cause a map reader to wonder, “where is north from any point on the map and is a north arrow specifying the direction to north for its location on the m