"An agent-based Water Supply Model as a link between the physical and the socioeconomic section of the hydrological cycle on a river basin scale"
PDF-VersionRecently, integrated approaches to describe, model, and forecast physical, social, economic, and political processes related to the hydrological cycle, in particular with regard to Global Change, have gained worldwide attention both with administrative authorities, as well as in the research community. Within the GLOWA-initiative (Global Change of the Water Cycle, www.glowa.org, funded by the German Ministry of Research and Education (BMBF)), the Upper Danube watershed was selected as a representative mesoscale (A ~ 80.000 km²) test site in the temperate mid-latitudes. “GLOWA-Danube” is developing the Global Change Decision Support System “DANUBIA” to investigate the sustainability of future water resources management alternatives. Within DANUBIA, the water supply model strives to meet the water needs (quality and quantity) of consumers (household, agriculture, industry, tourism) at a reasonable and realistic price, and in doing so acts as the interface between supply and demand, that is between the natural science and the social science models. It is therefore not a conventional water supply model, which focuses on the specific technical functioning and optimisation of water supply structures. Rather, it is a more abstract model which attempts to display typical decisions made by stakeholders in water supply in response to changing demand and water availability and/or quality and which should show the evolvement of water supply systems or cost structures as a result of such (mainly economically driven) stakeholder decisions. Currently, water scarcity is not an issue in the Upper Danube basin. However, water scarcity may not necessarily be caused by physical (i.e. climatic) changes or increasing demands, but also by various political, technical, economic and infrastructural constraints. Water quality aspects, liberalization and privatisation tendencies, as well as technological inventions must be considered. Decision making occurs at different levels of the private and administrative sector, involves various stakeholders, and is influenced by changes from the local to the global scale. Modelling such a complex environment under consideration of around 3000 communities, 2000 water supply companies, and more than 15000 water wells and other intakes, is a challenging task and includes many aspects, the most interesting of which are presented in our contribution.