Marine sediment transport

Morphodynamics of sandy beaches are governed by sediment transport processes. Conceptualising the process of subaqueous and subaerial sediment transport and quantifying the magnitude of sediment transport have proven to be a difficult challenge. The challenge is reflected by the many concepts available that describe sediment transport and its relationship with hydrodynamic processes and sediment compositions. This chapter gives an overview of the most important concepts that are currently available and widely used to describe sediment transport processes.

Concepts include timescale-dependent sediment transport as a function of different hydrodynamic processes such as waves, currents and turbulent forces. Also, the role of sediment properties and the most important modes of sediment transport, bedload and suspended load transport are discussed. In a further conceptualisation, cross-shore processes are distinguished from longshore processes given the nature of varying hydrodynamic gradients along the sandy beach. The rare measurements of sediment transport provide some evidence that help quantify the concepts.

Finally, reflection on current challenges that need to be addressed to achieve a more comprehensive and detailed model for sediment transport processes is made.