Geography Reference
In-Depth Information
systems (GIS). GIS were a new approach to electronically organising spatial data,
by combining a database of attributes with one of geographical co-ordinates,
where the attributes refer to points, lines or areas defined by the co-ordinates.
Although the majority of GIS applications are concerned with mapping, the term
GIS is increasingly used to describe a great diversity of computer-based applica-
tions involving the capture, manipulation, analysis and display of geographic
information (Wegener, 1998).
Based on the technological possibilities offered by computers and GIS, 'geo-
graphic visualisation' has significantly gained in importance during the 1990s.
Geographic visualisation refers to the ability of maps, graphics and images to make
spatial relationships and underlying spatial data patterns visible. In particular, the
term 'visualisation' refers to the added capabilities of interactive mapping software,
such as three-dimensional views, adding or removing data layers during data explo-
ration, and interactive map queries (Crampton, 2001). The emphasis is on the
exploration
of data (the process) rather than aspects of
presentation
(the product).
MacEachren (1994: 6) has defined visualisation in terms of map use, which
he conceptualised as a three-dimensional space defined by three continua without
clear boundaries (see Figure 2.2):
Figure 2.2
MacEachren's graphic characterisation of visualisation through the use of maps
Source: MacEachren (1994: 6)
