Ecohydrology, key-concept for large river restoration

Abstract

Successful restoration requires clear goals and objectives to succeed. Possibilities for and constraints of rehabilitation - both from a process-oriented view as well as from the nature conservation perspective differ strongly according to the landscape setting of a particular river segment and to the degree of anthropogenic changes. Large river restoration requires the development of an integrative scientific approach between ecology, hydrology and river engineering. For defining ecological targets and longterm sustainability of restoration programmes two aspects are particularly relevant. First, reference standards must be applied. Reference standards have to be based on the original landscape dynamics as defined by hydrology and bedload transport which resulted in a dynamic equilibrium of fluvial processes, habitat composition and consequently characteristic patterns of biodiversity and biogeochemical processes. The application of reference standards has to follow this cause-effect sequence. A second major requirement, dependent on this cause-effect chain between fluvial dynamics, habitat composition and ecology is the development of a prognostic ecohydrological parameter set which allows an evaluation of restoration scenarios and a prediction of their effects at a range of temporal and spatial scales.