Dinamiche di accumulo delle plastiche galleggianti al largo del delta del Po

Floating plastic pollution represents a growing pressure on coastal marine environments, especially in areas where river inputs, surface circulation and coastal morphology can promote the transport and concentration of debris. In this context, the Po Delta represents a particularly significant setting, as it delivers freshwater, sediments and particulate material into the northern Adriatic Sea, generating a dynamic surface plume that can be detected by satellite. This thesis analyses, using Sentinel-2 multispectral imagery, the possibility of identifying surface radiometric anomalies associated with floating material, potentially including plastic debris. The study focuses on the marine area off the Po Delta during April–May and August–September 2025. The scenes were subjected to a pre-analysis procedure aimed at making the images comparable, limiting the analysis to the marine domain and reducing the influence of coastal areas. Anomalies were detected using the Floating Debris Index (FDI), which is sensitive to increases in near-infrared reflectance relative to the aquatic background. The comparison among scenes shows that the FDI response is strongly conditioned by the configuration of the Po plume. In scenes with an extended or radiometrically active plume, the FDI > 0 threshold is poorly discriminating, whereas the most significant signals occur in the upper part of the positive distribution. The most coherent candidates tend to be located along the plume margins and in transition zones between turbid riverine waters and more offshore marine waters. The results do not allow the anomalies to be attributed with certainty to plastic, but they show that Sentinel-2, the FDI and contextual analysis can support a reasoned selection of candidates associated with possible surface accumulations, potentially compatible with floating plastic debris.