Sediment transport measurements and modelling in the Meldorf Bight tidal channels, German North Sea coast

Fine sand transport in the Meldorf Bight tidal channels, German North Sea coast based on field measurement and numerical modelling is studied. It comprises the description of sediment transport dynamics, reliability of sediment transport measurement and evaluation of the use of empirical formulae and numerical model for sand transport prediction. Measurements of current velocities using ADCP and suspended sediment concentrations using optical transmissometer for estimating sediment transport rates have been carried out in three main cross sections. Bed and suspended sediment property data are collected. Measurement results are used to develop and calibrate the numerical model for simulating time-series concentration and total load transport dynamics. A 2-dimensional model developed by the Delft Hydraulics is used. Sediment transport simulation is carried out based on measured and simulated velocities. Equilibrium sand transport formulae and the solution of advection-diffusion equation are used. Two empirical formulae for sand transport prediction are considered. Modelling performance is quantified using Relative Mean Absolute Error. Equilibrium sand transport formulae is found to be unable to handling conditions with lag effects. Improvement is made by using the solution of advection-diffusion equation. The modelling result is found to be able to reproduce the principal characteristics of concentration and total load transport dynamics in the investigation area