Bed forms under the combined action of waves and wind-driven currents in the remote foreshore of the non-tidal sea

Abstract

The paper presents a prediction of bed form parameters (length and height) in the remote foreshore of the non-tidal sea. The study site is located in the south Baltic region, near the Coastal Research Station (CRS) in Lubiatowo, Poland (ca. 1–2 Nm off the shoreline at depths of around 16–20 m). The study site is an area with hydrodynamics and lithodynamics typical of the south Baltic coast, built of fine sands. Predictions are based on numerical modelling with an input of measured data. Numerical modelling uses assumptions of specific relations of sand wave height and length with shear stress, grain size, kinematic viscosity, or storm event frequency. To establish these relations for the study area, wave, sea temperature and wind data were collected near CRS Lubiatowo. To verify the predictions made in this research, bathymetric data from a field survey in the study area was used. The results show that the flow is mostly current-dominated. Sand waves formed by hydrodynamic conditions in this area have a steepness of 0.01 to 0.02, a length of 40 to 70 m and a height of 0.6 to 2.3 m.