Prediction of changes in groundwater dynamics caused by relocation of river embankments

Abstract. Ecosystems in river valleys are affected mainly by the hydraulic conditions in wetlands including groundwater dynamics. The quantitative prediction of changes in groundwater dynamics caused by river embankment relocation requires numerical modelling using a physically-based approach. Groundwater recharge from the intermittently flooded river plains was determined by a leakage approach considering soil hydraulic properties. For the study area in the Elbe river valley north of Magdeburg, Germany, a calibrated groundwater flow model was established and the groundwater dynamics for the present situation as well as for the case of embankment relocation were simulated over a 14-year time period. Changes in groundwater depth derived from simulated groundwater levels occurred only during flood periods. By analysing the spatial distributions of changes in statistical parameters, those areas with significant impact on the ecosystems by embankment relocation can be determined.

Keywords: groundwater dynamics,groundwater recharge, flood plains, soil hydraulic properties, numerical modelling, river embankment relocation