This paper describes the technical infrastructure in place at BC Environment to support its province-wide implementation of fourteen ArcInfo and Oracle sites. It includes a GIS Working Group of all the GIS Coordinators; a provincial computer network; standards for hardware, software, and data; a distributed spatial and attribute data warehouse; a Data Registry metadata catalogue; a very easy-to-use end user viewer; desktop spatial/attribute data entry and editing; and public online access to datasets through the World Wide Web.
The P.O.P. SICILIA Water Resources Management project aims at providing the basis for improving the management of scarce water resources on the isle of SICILY. To this end a number of research activities have been set up ranging from basic research on how to monitor water quality and quantity to high level work on water management methodologies. Work is co-operatively carried out by the Joint Research Centre of the European Commission at Ispra (Italy) and the three main Sicilian universities. To promote synergy between the various activities, a distributed information system (DIS) based on WWW technology has been set up which seeks to integrate into a common system the various results emerging from different modules. The DIS allows comprehensive access to not only text and graphics, but equally to tables, databases and applications (e.g. water quality models), distributed among many servers. One of the more important modules in the project is the development of a decision support system for water resources management, technically based on an ArcInfo GIS and ORACLE database because of the georeferenced nature of most of the data available. It is believed that ARC and AML are suitable to create an effective standalone decision support tool for technical experts in the domain. Given the intention to make also applications a full part of the DIS and the difficulty to integrate existing applications with a graphical user interface such as an AML interface, we decided to investigate the possibilities of using WWW technology to engineer building blocks for constructing a client/server oriented decision support tool which would conceptually and technically seamlessly integrate with the DIS, and still use ArcInfo at the back-end, i.e. at the server side. Similar attempts have been undertaken in the recent past [], the success of which was seriously hampered by the limited possibilities of HTML and WWW clients/servers of that time. The limitedness in both choice and functionality of GUI widgets (FORMS widgets and ImageMaps), their awkward physical appearance and use on a single Web page, difficulties in creating dialogue threads in the 'state-less machine' regime and the impossibilities to by-pass the latter were a serious drawback. Only recently, non-standard extensions of HTML and suitably adapted WWW browsers, have made it possible to overcome these limitations. Concretely, the JAVA 'applet' concept and its integration within net browsers such as HotJava and Netscape provide the ground to overcome the previous limitations. In practice, it now becomes much easier to mimic the AML widgets in look and functionality at the client/browser side and to carry out complex graphical interaction with maps (e.g. drawing boxes and polygons) ; simple changes in the user interface content based on client side action no longer need to come from server responses but can come from a client loaded applet. Also, state-lessness is not an issue anymore since a connection with anon-JAVA application (such as ARC) can be held open by an appropriate applet. All these new advantages make that interaction from a client with a server located application such as ARC becomes much more flexible. This is explored in a few prototype examples geared towards water resource management. An objective evaluation of the above advanced Web technology and the prototype demonstrators are discussed in this paper.
Nick Gee