ABSTRACT
This chapter examines the concepts of space employed in current environmental models, and presents a list of criteria for the development of systems that allow an integrated conceptual modelling of spatial processes. These criteria are then used to evaluate current coupling of GIS and environmental modelling software. The flow chart-based user interface of VGIS is introduced as a visual programming and prototyping tool similar to STELLA® (HPS, 1994), but working with real GIS data and offering the full functionality of GIS. This user interface employs a small set of universal analytical GIS operations that facilitate ease of use by offering typical GIS functionality without the bulk of auxiliary operations that make most GIS so cumbersome to use. The conceptual modelling capabilities are exemplified by applications from environmental modelling.
