Floodplan restoration by means of water regime control.

Abstract A new approach for ecological restoration of floodplains of regulated rivers is presented. The emphasis is laid on restoring the most important abiotic factor, the water regime, which has undergone serious deteriorations due to anthropogeneous effects. The idea is to change the water regime on the floodplain for the benefit of ecology, by controlling the flow in the links connecting the floodplain depressions to the river and to each other. The viability of this approach is proven on a case study dealing with the restoration of a Danube floodplain. The flow control is proposed to be implemented on a passive way, by appropriately sizing the connecting channels and weirs of the floodplain. Accordingly, several restoration alternatives have been set up, evaluated and compared to each other. The evaluation is based on known relationships among ecology, hydrology and water quality. For the hydrological and water quality analysis, simulation models have been used. The comparison of alternatives is done by the ELECTRE II multi-criteria decision support technique.