Integrating modelling systems for environmental management information systems

Special purpose modelling packages can become more accessible and more effective for decision support when integrated into a spatial information system. Integration is made difficult by differences in the models due to scope, underlying data models, and command languages. This paper extends a federated information systems design methodology and architecture by identifying parallels of the model integration problem with the database integration problem in federated database design. A schema architecture is proposed together with associated schema translation functions. The role of a problem statement, analogous to a federated database query, is defined. Our design approach is demonstrated in HYDRA, a decision support system for water quality management.