Linking Local Multimedia Models In ASpatially-distributed System

The development of spatially-distributed multimedia models has traditionally required a fixed geometric grid or mesh, or an ad hoc spatial representation for a compartment-type model. As geographic information system (GIS) applications have matured, an alternative approach is evolving where the spatial components of the model and the physical-processes components are developed separately. At run time the physical process models are mapped onto the spatial domain, the simulation model is constructed and evaluated, and results are exported to the GIS system. In this approach one or more generic ‘local’ models are developed, then replicated across a spatial domain defined by a GIS system, connected to sources of spatial data, and finally the local models are interconnected to allow flows of information, physical media, and contaminants between the local models. This approach is designed to allow multiple models to be instantiated and interconnected at appropriate locations. For example, models of physical processes such as rainfall and runoff (and seepage, erosion, etc.), could be linked to biotic process models such as crop growth, and to multimedia contaminant transport models. The paper discusses alternative underlying conceptual approaches for this type of modelling, and presents the methodology selected for the GoldSim simulation software package.