A concept for the development of model indicators for policy makers to adapt German inland waters to climate change

Indicators are used for reducing complexity and for highlighting decision relevant topics and relationships. In response to actual transition processes currently taking place in the German inland waters management system, the objective of the research programme KLIWAS (Impacts of climate change on waterways and navigation - Searching for options of adaptation) is the assessment of climate-induced changes of flows and water levels , taking into consideration the uncertainties in climate projections. The main aspect of the indicator concept in KLIWAS is to translate relevant information to make it usable for policy makers. This necessitates a scientifically based formulation of indicators. The KLIWAS system approach and multi-model approach help to build this scientific base. We analyse user requirements and develop a concept for suitable indicators, mainly related to the ecological and economic issues of the maintenance of German inland waterways. This concept will support policy makers while assessing the efficiency of adaptation measures to manage the impacts of climate change. Therefore, the indicators are compared and contrasted with a set of decision-relevant parameters. The later set is derived from technical and administrative policy objectives for the operation and maintenance of waterways. We are also considering the existing legal requirements for river basin management. The models applied in the research programme will be analysed with regard to these indicators. The significance of the indicators will be evaluated, and requirements for the model development will be formulated. Our objective is to build an indicator concept which helps to answer the following questions: Where is the system of German inland waters impacted by climate change effects? What environmental and economic effects follow these possible impacts?