GIS Cartographic Functionalities

Advantages and disadvantages of cartography using GIS

It is true that analysing data is the real power of GIS, but analysis is wasted if you can not communicate your results. This is why more and more GIS includes some powerful cartographic tools. However, most of them are not adapted to the user and often violate cartographic convention. Furthermore, when analysing spatial data in a GIS, some temporary displays are quite often produced which are of course not intended for map communication.

Advantage of cartography using GIS

The technology of GIS mapping has evolved a lot in the last 10 years. This is why the GIS user has currently a wide range of functionalities and mapping tools at his disposal. Mapmakers which use GIS are no longer limited to simple black-and-white, letter-size pages produced on an office printer. You have now the choice of producing dazzling full-color paper maps from letter to poster size, high-quality published map products, and interactive maps with a GIS. With GIS you can easily:

• Create maps semi-automatically
• Manage layers
• Symbolise data
• Label maps with text and graphics automatically
• Layout and print maps
• Work with styles and symbols
• Look at data with graphs
• Create reports
• Query maps

You can optionally have a look at the following link to get some more information about “Cartographic Design using ArcView GIS”: http://learn.arcgis.com/en/arcgis-book/. As cartography is a specialised form of graphic communication that requires training, practice and a certain sense of style, GIS will never (now as well as in the future) allow you to create automatically “National Geographic” quality maps. You will learn, that most of the cartographic outputs from GIS are bad or false from a cartographic point of view.

Discover the cartographic tools within a GIS with some examples: Push the blue arrow on the right bottom to explore the slideshow.

Disadvantage of cartography using GIS

When creating a map, if the user does not indicate a projection and grid system, a number of GIS software packages default to a “Plate Carree Projection”. „Plate Carree” is a projection which distorts the shape, area, and scale as the displays moves away from the equator. And therefore, there are countless examples of bad maps whose creators do not realise that they must indicate an appropriate projection (the default projection is, of course, usually not the best. This is a classic problem by using GIS for cartographic purposes: the user has not to understand the characteristics of the data or of the mapping techniques used because the GIS automatically selects the default settings. This problem is exactly the same for many other cartographic considerations like:

• Classification: The classification tools included in most current GIS package allows quick and easy classing schemes. This can lead to inappropriate choice, because no significant experimentation is needed. Another factor to consider is the number of classes: the default number of classes in GIS package is frequently too high: nine or ten, whereas five or six classes are enough.
• Text Placement: Labelling points, lines and polygons automatically is often imprecise or cartographically false. Overposting (labelling for one feature placed on top of labelling for another feature), bad polygon labelling (on left/centre/right) are other placement, are classic errors.
• Colour schemes: Often the default colour schemes are qualitative, this can be a real problem for choropleth mapping (which use quantitative data).

If your still want to create your map with GIS, never accept GIS default parameters as cartographic standards, and take in consideration that your map will look like a draft because colour calibration does not occur within GIS. You can optionally download the following PDF to get some more information about classic errors of using GIS for cartography: “GIS Cartography Courses in GIS Certification Program"(326 Kb).