Potentials and measures for the restoration of retention areas: the Lahn River example in Germany

摘要

The first part of the contribution deals with the historical development of the Lahn, including the flood plains, under the influence of the use by man since 1850. It is stated, how the reduction of retention areas has affected the flood situation. The recoverable retention areas are defined by overlapping the potential flooding areas with the actual land use. Subsequently, measures that can reactivate the existing retention potential are described. By the example of a typical stream section, the fundamental effect as well as the pro and cons of the respective measure are illustrated. A summary of the project was published in Lang et al, (2002). The second part of the contribution deals with the realization of the concept. The conflict potentials that should be considered during the reactivation of retention areas are briefly described. The possible flood peak and water level reductions obtained with the help of simulation results from a hydrologic modeling system are shown. Further information on the environmental compatibility and the costs of the measures are presented.