A knowledge-based approach to the management of geographic information systems for simulation of forested ecosystems

The authors present a knowledge-based approach for a geographically based information system designed to infer and simulate objects using simple attributes. Higher order objects are recursively defined using query models and aggregation. They are organized and accessible as distinct, identifiable landscape units such as hillslopes and forest stands. Object-oriented and knowledge-based tools simulate ecosystem processes on the basis of higher order geographic features. Ecological simulations are organized around a model of terrain based on a hierarchy of nested watersheds, hillslopes and streams. They organize spatial relations into a graph of topological links around which is built a graphical query interface. The interface translates user requests into database queries using a query model that maps graphical objects to database objects. This system insulates the user from implementation details of the simulation system, and that it can manage the ecological/spatial objects in a transparent manner throughout simulation experiments. -Authors