Author(s): W. A. Breugem; B. Teunkens; K. Chu; T. I. Koutrouveli; S. Van Damme; B. Decrop

Linked Author(s):

Keywords: Macroplastics; Plastic pollution; Scheldt Estuary; TELEMAC-3D; Acoustic telemetry; GPS tracking

Abstract: In order to obtain a better understanding of the transport of macroplastics in rivers, a new module is developed in the shallow water flow solver TELEMAC-3D, which uses particle tracking to simulate the motion of macroplastic objects. Important physical processes, such as settling and rising of plastic objects (including the effect of biofouling), the influence of wind on floating plastics as well as the interaction between plastic objects and the riverbed are taken into account. The new module is applied to the Scheldt Estuary, a well-mixed macro tidal estuary in Belgium and the Netherlands. It is validated using high quality data from the University of Antwerp, obtained by tracking the motion of marked macroplastics set on plastic. The transport of floating plastic objects in the model is validated using data from floating GPS sensors. The movement of both floating items and items moving as bedload are validated using a dataset of general household plastics, which are equipped with acoustic tags. The latter allowed to track macroplastics using an existing network of acoustic receivers, normally used to tracked fish. A direct comparison is difficult, because the motion of macroplastics is inherently stochastic. Nevertheless, the model and the measurements show the same tendency in the upstream branches, in that they aggregate in the same areas. In particular floating plastics move faster than items moving as bedload. The floating macroplastics aggregate at the river banks in both the model and the observations. However, tracked items can stay immobile for a substantial amount of time, which does not happen in the model.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0201-cd

Year: 2023