Managing Droughts in Northern Germany—The Reconect NBS Approach and Water Resources Model for Vier- Und Marschlande Area, Hamburg, Germany
In order to analyse the long-term effects of droughts and assess possible nature-based solutions to cope with them, a sociotechnical approach together with a water resources management model (RMM) has been developed within the RECONECT Project. Following the four step approach, the overall conceptual design is performed (step 1) taking into the consideration all relevant socio-technical aspects such as the key stakeholders, so as the relevant physical processes and their interactions. In step (2), the developed conceptual model is operationalised to assess the current and possible future situations in a given area. Mathematical models are set up. A thorough stakeholder analysis is performed. In step (3) the possible combinations of NBS and hybrid measures are co-created. In step (4) the benefits of the defined measures to mitigate the adverse effects of droughts are assessed and quantified utilising the developed models and methods. The potential co-benefits are assessed. The transferability and replication of the method is discussed and recommendations drawn. This approach has been applied to the area of Vier- und Marschlande in Greater Hamburg, which belongs to the German Demonstration Case within RECONECT. A thorough Status Quo analysis has been performed and a set of measures are co-created focusing on the main water extraction area of Curslack. The preliminary results indicate a strong interplay among the elements of the surface and ground water bodies in the area. In the following step, the benefits of the selected measures to mitigate droughts will be quantified and the possible co-benefits analysed, contributing to the general rethinking of the current practices in Northern Germany and beyond.