The What if? collaborative planning support system

In this paper I will describe What if?, a scenario-based, policy-oriented planning support system (PSS) that uses increasingly available GIS data to support community-based processes of collaborative planning and collective decisionmaking. It incorporates procedures for conducting land suitability analysis, projecting future land-use demands, and allocating the projected demands to the most suitable locations. The system allows users easily to create alternative development scenarios and determine the likely impacts of alternative public-policy choices on future land-use patterns and associated population and employment trends. It is easy to use, can be customized to the user's database and policy issues, and provides outputs in easy to understand maps and reports.