River training works have often led to a reduced hydrodynamical and morphodynamical variability and an impoverished ecological value. The effective implementation of renaturalization projects requires a good knowledge on hydrodynamical, morphodynamical, and ecological processes occurring in river systems. Specifically, the mutual interactions between the physical and biological components of the ecosystem represent a main challenge for projects aiming to increase stream biodiversity. Recent research projects handling both physics and biology in rivers have demonstrated the importance of cross-disciplinary research. One of those projects concerns a collaboration between the Leibniz-institute for Freshwater Ecology and Inland Fisheries, Delft University of Technology and Ecole Polytechnique Fédérale de Lausanne, which is sponsored by the German Research Foundation (DFG) and the Netherlands Organisation for Scientific Research (NWO). This project has led to the initiative to organise a small-scale colloquium on ecohydraulics with the aim to bring together scientists and engineers with a strong interest in environmental flows, river morphodynamics and aquatic ecology. The main topics are :
- Drift, distribution and biodiversity of invertebrates related to hydraulic stress,
- Sediment transport, morphodynamic processes and dispersion,
- Fish behaviour in relation to flow and morphology,
- Vegetation development and flow and sediment interactions,
- Eco-engineering and stream restoration.