DANUBIA: An Integrative Simulation System

We describe the concepts and design principles of the integrative simulation system DANUBIA which supports the analysis of water-related global change scenarios in the Upper Danube Basin. DANUBIA provides an internet-based platform integrating the distributed simulation models of all socio-ecological and natural science disciplines taking part in the GLOWA-Danube project which is part of the German Programme on Global Change in the Hydrological Cycle. As a result of coupled simulations transdisciplinary effects of mutually dependent processes can be analysed and evaluated. Actually thirteen simulation models of meteorology, landsurface, water research and social sciences are integrated in the DANUBIA-system. The development of DANUBIA is based on object-oriented software engineering and Web engineering methods ([2, 8, 9]) and on the Unified Modeling Language UML [1] which is used by all partners as a common graphical notation for modelling the integrative aspects of the system. We describe how the mutually exchanged information between components is modelled and documented by interfaces, we discuss spatial aspects and show how simulation areas are represented and we consider temporal aspects and describe the coordination of local models by a global time controller which constitutes the heart of any integrative DANUBIA simulation. Finally, we provide an overview of the architecture of the DANUBIA implementation which has been realised in Java. The implementation integrates a wrapper framework that hides the technical details of network communications.