A methodology to assess the probability of marine litter accumulation in estuaries

In this study, a general methodology that is based on numerical models and statistical analysis is developed to assist in the definition of marine litter cleanup and mitigation strategies at an estuarine scale. The methodology includes four main steps: k-means clustering to identify representative metocean scenarios; dynamic downscaling to obtain high-resolution drivers with which to force a transport model; numerical transport modelling to generate a database of potential litter trajectories; and a statistical analysis of this database to obtain probabilities of litter accumulation. The efficacy of this methodology is demonstrated by its application to an estuary along the northern coast of Spain by comparing the numerical results with field data. The necessary criteria to ensure its applicability to any other estuary were provided. As the main conclusion, the developed methodology successfully assesses the litter distribution in estuaries with minimum computational effort. •Clustering and numerical models enable the study of litter distribution in estuaries.•K-means successfully describe biweekly multivariable ocean states.•Estuarine physical features implemented in transport models influence accumulations.•Marine litter tends to accumulate near litter sources and on beaches.