The developed model coupling approach has been applied to couple various models, including transportation, land use, land cover, emissions and water quality models. The task was complicated since in spite of covering the same region all those models have been developed independently without any built-in method for linking to other models. Moreover, they have been developed in different programming languages, software environments and have various licensing restrictions, making their integration a challenging task.
The project explored diverse model coupling approaches and evaluated their applicability for the research needs. However, the existing couplers have been developed with different objectives and constraints in mind. None of the identified couplers were suitable for the defined integration task covering. Therefore, a loose model coupling approach was developed using specific model wrappers, which separate the implementation of the couplers from the models’ source codes. This gives a flexibility, which can help in terms of portability, performance and maintenance of the model codes. The approach is especially efficient when the models are developed in different programming languages, their source codes are not available or the licensing restrictions or limited resources are making other coupling approaches infeasible. It offers a viable solution to coupling such models without the need of change or even access to the sources codes.