GIS Files 6: Expert GIS concepts

6.4: Derived mapping (3)

Automated cartography

In Chapter 2 we showed how the appearance of vector data can be readily altered using symbols and different line styles. In the two previous sections of this chapter we examined the more advanced concepts of generalisation and text placement. These ideas, and more besides, are all relevant to the automatic generation of products from source GIS data that are meaningful and useful to us.

When we talk of automated cartography, what we are trying to achieve is a fundamental GIS goal of capture once, use many times. In other words, it’s inefficient to go through the process of manually creating an aesthetically pleasing map every time something changes. It’s far more desirable to automatically represent and display the source data as often as required and in an infinite variety of ways. Modern GIS software can be used to rapidly and efficiently generate highly complex maps from basic point, line and polygon features.

Automated cartography can become a highly sophisticated business. In addition to overcoming the problems of scale differences and placing text appropriately, we may also wish to generate different kinds of map for different users. For instance, to create a map oriented in the direction in which someone is travelling or with colours that aren’t affected by one person’s colour blindness.

Electronic data and electronic displays enable new forms of cartography to be developed. For instance, standard data formats such as Virtual Reality Mark-up Language (VRML) allow maps to become virtual three-dimensional worlds that you can explore as if you were flying through the landscape. Furthermore, geographical data is not necessarily best represented as a map. In many cases we are more interested in direct information, such as navigation instructions, which might be delivered as text or as synthesised voice. Where will this lead? Smelly and tasty GIS?

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