DOI 10.1007/s11269-009-9445-y Using the Multiactor-Approach in GLOWA-Danube to Simulate Decisions for the Water Supply Sector Under Conditions of Global Climate Change

Abstract Glowa-Danube (www.glowa-danube.de) is an interdisciplinary project that aims to develop integrated strategies and tools for water and land use man-agement in the upper Danube catchment (Germany, Austria ∼77,000 km2). The project is one of five within the Glowa research program (www.glowa.org) dealing with Global Change effects on the water cycle in six meso-scale catchments (up to 100,000 km2) in Central Europe, West Africa and the Middle East. In the Glowa-Danube project, 16 natural science and socio-economic simulation models are integrated in the coupled simulation system Danubia. This article describes the underlying concept and implementation of WaterSupply, a multiactor-based model of the water supply sector with a focus on water resource utilization and distribution of individual water supply companies. Within Danubia, WaterSupply represents the link between water supply and demand, where the former is simulated by a groundwater and a surface water model and the latter by water consumption models of four different sectors (domestic, industrial, agricultural and tourism). WaterSupply interprets the quantitative state of water resources for defined spatial and tempora