Recommendation: Preferential deposition of macroplastic on floodplains — R0/PR4

Le résumé fourni par la source

Floods have a large impact on the mobilization, distribution and retention of macroplastic in rivers. Some of the transported plastic is deposited on riverbanks and floodplains. However, the specific deposition patterns, that is, where precisely macroplastics are deposited across the floodplains, are poorly investigated. We sampled 25 floodplain sites along the Meuse following the 2021 summer flood (>100 year). For each found item, we recorded the landcover element (such as grass, herbaceous, bushes, tree and debris pile) in which it was deposited. Along the IJssel, debris piles contained plastic concentrations of 12.7 #/m2 and 58% of plastic by count, despite covering only 2% of the sampled area. We found that plastic concentrations vary between landcover elements, but also plastic characteristics. Out of the macroplastics deposited in riparian vegetation along the Meuse, 84% were soft plastics or textiles, compared to 53% of items deposited on the ground. This article sheds additional light on the role of vegetation and debris piles on plastic retention caused by floods. Our results can be used to help improve the monitoring, mitigation and reduction of river scale plastic pollution.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.