DANUBIA: A Web-Based Modelling and Decision Support System to Investigate Global Change and the Hydrological Cycle in the Upper Danube Basin

We describe architecture and design principles of the integrative modelling and simulation system DANUBIA. The system integrates the distributed simulation models of the socio-economic and natural science disciplines of the GLOWA-Danube project. During an integrative simulation the simulation models run in parallel and exchange iteratively data. The validity of the exchanged data with respect to model time is guaranteed by a central time controller which coordinates the single simulation models. The consistency of spatial data is ensured through the common proxel concept used by all models. The development of DANUBIA is based on object-oriented software engineering methods. A generic framework architecture has been constructed which implements general rules for the behaviour of all simulation models. It can be specialised and thus instantiated by concrete simulation models. We also have developed a particular framework for the socio-economic deep actor models.