Search

The transport of plastic particles from inland sources to the oceans garbage patches occurs trough coastal regions where the transport processes depend highly on wave‐induced motions. In this study, experimental measurements of the plastic particles wave‐induced Lagrangian drift in intermediate water depth are presented investigating the influence of the wave conditions, particle size and density on the motion of relatively large plastic particles. A large influence of the particle density is observed causing particles to float or sink for relative densities lower and larger than water respectively. The measured net drift of the floating particles correlates well with theoretical solutions for particle Stokes drift, where the net drift is proportional to the square of the wave steepness. Floating particles remain at the free water surface because of buoyancy and no evidence of any other influence of particle inertia on the net drift is observed. Nonfloating particles move close to the bed with lower velocity magnitudes than the floating particles’ motion at the free surface. The drift of nonfloating particles reduces with decreasing wave number, and therefore wave steepness., Key Points A 16 m wave flume is used to measure wave transport of floating and non‐floating plasticFloating plastic transport correlates well with Stokes drift and buoyancy is the only non‐inertial effectNon‐floating particles experience shear forces. Transport varies with particle size and density

The swash zone is a highly dynamic boundary between the beach and the surf zone. Swash processes determine whether sediment is either stored on the upper beach or is transported offshore, and thus strongly affect shoreline evolution. The present research focuses on the hydrodynamics, sand transport processes and net sediment transport in the swash zone through a series of large-scale wave flume experiments. This research aims to improve the understanding of swash zone sand transport processes, in particular the role of cross-shore sand advection and wave-swash interactions, and bring new detailed insights into the relation between intra-swash processes and net sand transport rates.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/tYvJ0pML-kU

The swash-zone is a highly dynamic area with large sediment fluxes within a shallow, transient water layer. Connecting the surf zone to the beach, the swash is a relevant area for coastal morphology. Obtaining high-quality measurements in the swash has been proven challenging. Therefore, the complex physical processes driving sediment transport in the swash are poorly understood. We present results of recent large-scale wave-flume experiments, focusing on sheet-flow sediment transport in the swash zone.

Marine plastic debris floating on the ocean surface is a major environmental problem. However, its distribution in the ocean is poorlymapped, and most ofthe plastic waste estimated to have entered the ocean from land is unaccounted for. Better understanding ofhow plastic debris is transported from coastal and marine sources is crucial to quantifyand close the global inventory ofmarine plastics, which in turn represents critical information for mitigation or policy strategies. At the same time, plastic is a unique tracer that provides an opportunity to learn more about the physics and dynamics of our ocean across multiple scales, from the Ekman convergence in basin-scale gyres to individual waves in the surfzone. In this review, we comprehensively discuss what is known about the different processes that govern the transport offloating marine plastic debris in both the open ocean and the coastal zones, based on the published literature and referring to insights from neighbouring fields such as oil spill dispersion, marine safety recovery, plankton connectivity, and others. We discuss how measurements ofmarine plastics (both in situ and in the laboratory), remote sensing, and numerical simulations can elucidate these processes and their interactions across spatio-temporal scales.