Custom GIS projects require custom map design. The design you use should be targeted to your audience. Cartography is the art of designing a map. There are some guiding principles. Certainly there are some challenges. One common challenge relates to placing labels on maps.
Here’s some common labelling problems that people have when they’re creating GIS maps
- Random colours.
- Random icon sizes.
- Design that does not consider the way the map will be printed, or only viewed on-screen.
Placement of Map Labels
There are many ways to identify map features. These include a combination of symbol and label design in combination with color and size.
Eduard Imhof has written extensively on the positioning of map labels. For him, labels on maps…
- Should be legible.
- Should be easily identifiable with their corresponding features.
- Should not overlap.
- Should employ different font styles to indicate the hierarchy of the features.
- Should not crowd the area or have even distance between them.
A map densely packed with labels that overlap each other destroys the purpose of the labels. When labels overlap its known as over-posting.
Solution: Carefully select key point features. Wherever possible, the labels should be above and to the right of the point.
Wherever possible, the label for a polygon should be in its centre, and can be curved to fit inside.
The polygon can be labelled using the following techniques…
- Labelling on centroid of polygon but this may cause a long label to be multi-line and it does not represent the extent of the shape.
- A rectangle inside the polygon but the ratio of the rectangles length and width is to be taken into consideration.
More on map design in my…