Monitoring and modelling macroplastic transport in riverine systems from reach to catchment scale

Plastic transport processes in inland fluvial systems remain poorly quantified, particularly at larger spatial and temporal scales. In this study, we aim to investigate macroplastic transport dynamics across multiple river reaches, even river system using a combination of field observations, remote sensing, and modelling approaches, with relevance at catchment scale.

We are developing an integrated monitoring system capable of continuously surveying extended river sections using multiple fixed monitoring stations equipped with IP cameras and automated object detection algorithms. In addition, unmanned aerial vehicles (UAVs) are employed for rapid assessments of highly polluted areas and spatially heterogeneous accumulation zones. The primary output of this system is a continuous time series of macroplastic fluxes across multiple river cross-sections, enabling direct coupling with hydrological, meteorological, and catchment-scale land use data.

To further investigate macroplastic transport pathways, accumulation zones, and remobilization processes, we are also developing and testing GPS-equipped plastic tracers that can be tracked over extended periods with meter-scale positional accuracy. These observations allow the identification of trapping zones, residence times, and remobilization probabilities under varying hydrological conditions, including the influence of extreme events such as floods and low-flow periods.

The collected spatio-temporal datasets address current gaps in long-term, reach-to-catchment scale observations of macroplastic transport in freshwater systems. These data are intended to support and calibrate hydrodynamically driven, particle-based (Lagrangian) transport models, improving our understanding of macroplastic source-to-sink dynamics and the role of hydrological and land use controls on plastic accumulation and export in riverine environments.