Hydrodynamics and particulate matter budget of Königshafen, southeastern North Sea

Abstract

A basic control mechanism for the input and output of materials in the Königshafen, a sandy backbarrier embayment, is the action of the tides. Thus, the description of the hydrodynamic conditions provides basic information for further investigations in the Königshafen. On the tidal fltas and in the western part of the tidal creek, the near-bottom residual currents are weakly fooddominated. In the other parts of the tidal creek, the flood and ebb currents are well balanced. During high tide, the suspended matter shows an increase towards the inner part of the bay. The concentration of suspended matter, its distribution and the currents are influenced by wind action. During westerly winds up to 4–5 Beaufort, the concentration of suspended matter in the embayment varies between 1 and 15 mg l−1. During storms with westerly winds, the near-bottom residual currents are orientated into the bay, and the concentration increase by a factor of about 2. Strong easterly winds in combination with a water level of 0.5 m below mean high water level and an increasing wave energy cause considerable resuspension on the tidal flats of the Königshafen embayment. For this reason, the concentration of suspended matter increases by factor of about 20.