Can Forel–Ule Index Act as a Proxy of Water Quality in Temperate Waters? Application of Plume Mapping in Liverpool Bay, UK

The use of ocean colour classification algorithms, linked to water quality gradients, can be a useful tool for mapping river plumes in both tropical and temperate systems. This approach has been applied operational programs the Great Barrier Reef map assess trends marine composition ecosystem health during flood periods. In this study, we used Forel–Ule algorithm Sentinel-3 OLCI imagery an automated process monthly, annual long-term plume movement coastal system Liverpool Bay (UK). We compared monthly extent flow situ data between 2017–2020. results showed strong positive correlation (Spearman’s rho = 0.68) link FUI defined waterbodies nutrients, SPM, turbidity salinity, hence potential index act as proxy water. paper discusses how could better understand land-based inputs zones UK waters, drawing parallels with methods that have developed GBR Citclops project. Overall, provides first insight into systematic waters using fast, cost-effective, reproducible workflow. study created novel assessment typology based on common physical, chemical biological properties captured index, which replace more traditional eutrophication regions centred around strict geographic political boundaries. Additionally, is particularly important since it identifies areas greatest impact from loads environment, thus risks vulnerable ecosystems.