Field Verification of 2–D and 3–D Suspended‐Sediment Models

Abstract

A tidal channel in the Eastern Scheldt estuary in the Netherlands is closed by pumping a sand‐water mixture into the closure gap. During the closure, fields measurements of flow velocities and sand concentrations are carried out. Based on the results of the field measurements, computations with two‐ and three‐dimensional sediment transport models are carried out. The two‐dimensional computations show that the depth‐integrated transport rates can be reasonably predicted (within a factor of 2) in case of diverging flow. But less satisfactory results are obtained for converging flow. The three‐dimensional computations show quite good agreement between measured and predicted flow velocities, sediment concentrations, and transport rates, both for flood and ebb flow. A sensitivity analysis with respect to the time‐dependent concentration term, the shape of the velocity profiles, the turbulent mixing coefficients, and the bed material gradation is carried out. The results show no significant influence of these parameters. The main reason for the difference between measured and predicted results is caused by the formula modeling the sediment pickup rate (at the bottom).