First calculations on determining the interference of the currents close to the sluice were carried out with a simple 1D model. A subsequent order was given for further profound investigations using a 2D hydrodynamic model of the Elbe estuary based on an existing model. The model area reached from the City of Geesthacht to Hamburg-Blankenese (Fig. 1). Tidal gauges at different places along the Elbe estuary were used for the calibration of the hydrodynamic model. An ecological process model was included into the hydrodynamic model in order to calculate the oxygen budget. In 2010 additional measurements of oxygen contents, current velocities and sediment parameters were carried out which should serve as basis for the calibration of the ecological model. It has to be mentioned that strong variations in the measured oxygen concentrations occurred due to different reasons (for instance sediment clouds due to ship maneuvers; surface runoff after rainfalls of organic polluted surface water). These can’t be observed within the model in detail
Three questions were investigated:
- Is there an import of oxygen into the area by the fresh water discharge?
- What is the influence of suspended sediments, which are remobilized due to higher current velocities nearby the sluice?
- Can the chosen modified sluice management guarantee sufficient exchange of the water volume?