In order to predict waterlevel changes in rivers due to floodwaves and local bedshapes for navigation, the local behaviour of the riverbed should be known . In many cases the bed of 3 river consists of dunes, which propagate downstream due to the sediment transport along the dunes . In this report mainly the watermovement but also the sediment transport along a dune is studied. The investigation consists of a theoretical and an experimental part. In the theoretical part a calculation of the flowfield above a dune is carried out us ing a computer model for the watermovement (ODYSSEE computer program of the Delft Hydraulics Laboratory, DHL). In the experimental part the mechanism of the local sediment transport along the dune is studied. The experimental set up consists of a solitary sanddune on a conveyor belt in a flume . The position of the dune is constant due to: conveyor belt velocity = propagation velocity of the dune . In this situation the flow field above the dune is measured using a Laser Doppler Anemometer (LOA), which is tested first in a uniform flov1 situation . The local sediment transport, which is known along the steady dune, is related to the local bed shearstress.Hydraulic EngineeringCivil Engineering and Geoscience
