An Integrated Simulation System for Global Change Research in the Upper Danube Basin

1 This work is part of the GLOWA-Danube project sponsored by the German Federal Ministry of Education and Research. Abstract: We give an overview of the architecture and design principles of the integrated simulation system DANUBIA which supports the analysis of water-related global change scenarios in the Upper Danube Basin. DANUBIA is designed as 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 objectoriented software engineering and web engineering methods ([2], [3], [4]) and on the Unified Modeling Language UML [1] which is used by all partners as a common graphical notation for modeling the integrative aspects of the system. In the following overview we first describe how the mutually exchanged informations between components are modeled and documented by interfaces. Then we discuss spatial aspects and show how simulation areas are represented. In a next step temporal aspects are considered and the coordination of local models by a global time controller is described which constitutes the heart of any integrative DANUBIA simulation. Finally, we provide an overview of the architecture of the first DANUBIA implementation which has been realised in Java. This implementation integrates a wrapper framework that hides the technical details of network communications for the single components. 1. Components and Interfaces