Abstract
Successful Web GIS (Geographical Information System) applications are achieved by the right combination of GIS layers symbolised in a visually dynamic way, with an easy to use application, that is stable and responsive and meets the user requirements of both GIS and non-GIS users. Web 2.0 has produced a flood of development starter kits, sample viewers and APIs (Application Programming Interface), with the result that almost anyone involved in GIS or IT (Information Technology) – even with limited or no programming experience – can build a GIS website. This has lead to an exponential growth of Web GIS applications and data, which although a necessary step in increasing accessibility to spatial data and GIS applications, may result in online mapping applications that do not satisfy user requirements. The Gauteng City-Region Observatory (GCRO) identified a business need to develop a Web 2.0 GIS website to enable users to attain a better understanding of the Gauteng City-Region (GCR). The website makes use of data mashups to integrate data from various sources, and is one of the first government GIS websites in South Africa to utilise open datasets such as Google Maps to provide the base data. The website was built using rich Internet application (RIA) technology provided by the ESRI Adobe Flex viewer to offer an enhanced user experience, with popup windows and dynamic graphs linked to the maps. A five step Web GIS development methodology was employed to build the GCRO GIS website. This paper will examine each of the GIS development design steps that were followed to ensure an optimal functioning application, with responsive and secure map services. Specific Web mapping optimisation techniques, such as applying specific cartographic techniques and map designs to assist in overcoming the additional layer of Web design complexity introduced by spatial data will be reviewed.