Floodplain restoration on the Upper Danube (Germany) by re-establishing water and sediment dynamics: a scientific monitoring as part of the implementation
Stammel, Barbara; Cyffka, Bernd; Geist, Jürgen; Müller, Melanie; Pander, Joachim; Blasch, Gerald; Fischer, Peter; Gruppe, Axel; Haas, Florian; Kilg, Markus; Lang, Petra; Schopf, Reinhard; Schwab, André; Utschik, Hans; Weißbrod, Maximilian
Like most European rivers, the Upper Danube has been embanked and straightened, and hydropower plants have been built on it since the 19 th century. The river and floodplain became disconnected, the hydromorphology changed dramatically and the typical floodplain habitats, such as softwood and hardwood riparian forests, have been suffering. The presented project aims to restore the former floodplain habitats by bringing back water and sediment dynamics to the area. Three measures were implemented, notwithstanding the still existing dams: a new floodplain river was created, water will be diverted for yearly ecological flooding, and the constantly high groundwater level will be drained from time to time. To improve the measures, an extensive monitoring program was installed and should support an adaptive management. Due to the lack of other studies on monitoring designs, the monitoring program (covering the linear river and the two-dimensional floodplain) is described in detail for the single parameters, expectations and methods. The baseline data and preliminary results of the investigated objects hydromorphology, vegetation of the (semi-)aquatic habitats and the alluvial forest, its vitality, and the fauna (birds, arthropods, molluscs in the floodplain, aquatic biodiversity), were presented. They show, on the one hand, the need to restore the floodplain based on the deficits assessed and, on the other hand, the quick reaction of some parameters to the first measures.