The emergence of geoportals and their role in spatial data infrastructures

Geoportals are World Wide Web gateways that organize content and services such as directories, search tools, community information, support resources, data and applications. This paper traces the emergence of geoportals, outlining the significance of developments in enterprise GIS and national spatial data infrastructures (SDIs), with particular reference to the US experience. Our objectives are principally pedagogic, in order to relate the development of geoportals to SDI initiatives and to review recent technological breakthroughs--specifically the development of direct access facilities for application services and metadata records, and the facility to utilize services directly from conventional desktop GIS applications. We also discuss the contributions that geoportals and SDI have made to simplifying access to GI, and their contribution to diffusing GI concepts, databases, techniques and models. Finally, the role of geoportals in electronic government (e-Government) is considered.