Author(s): V. K. Tsoukala; Daniil; C. I. Moutzouris

Linked Author(s):

Keywords: Coastal structures; Water quality; Breaking waves; Oxygenation

Abstract: Oxygenation experiments under breaking waves in the coastal zone in small and large-scale experimental facilities are presented. Small-scale experiments were performed at the wave flume of the Laboratory of Harbour Works, NTUA with a uniformly sloping beach and a rubble mound breakwater. Large-scale Experiments were performed with a sloping beach at the wind wave flume of Delft Hydraulics and a three-layer rubble mound breakwater at the Schneideberg wave flume of Franzius Institut in Universitat Hannover. Although the apparent transfer coefficients for the large scale experiments were lower than those determined from small scale experiments, the actual oxygen transfer coefficients, as computed using a discretized form of the transport equation and accounting for dispersion, are in the same order of magnitude for small and large scale experiments. A modified vorticity based renewal model incorporating the breaking wave Reynolds number is proposed, that describes both small and large scale experimental data well. Additionally, field measurements of dissolved oxygen concentrations around a harbour area near Athens indicating the positive effect of the rubble mound breakwater on the water quality of the area are presented. Measured concentrations on the seaward side of the breakwater are significantly higher compared to those measured in the harbour basin and along the neighbouring beaches.

DOI:

Year: 2001