Beneath the Surface: How Climate Change Intensifies Erosion and Suspended Sediment Loads

Abstract This study leverages high-resolution climate datasets and advanced hydrodynamic modelling tools to propose a methodological procedure for assessing the potential impact of changes in atmospheric patterns on marine bottom stress and erosion processes occurring on the seabed. The analysis focuses on the Mar Piccolo basin of Taranto, a coastal area in southern Italy where marine sediments are heavily impacted by both past and ongoing anthropogenic pollution. Hydrodynamic simulations performed to define medium-term future scenarios indicate that, starting from 2035, a marked increase in current intensity is expected in both surface and bottom layers. This shift in current dynamics can be mainly attributed to changes in the wind regime. The enhanced current intensity is expected to lead to stronger shear stresses at the sediment-water interface, exceeding the critical thresholds for sediment resuspension, favouring sediment mobilization. These outcomes highlight the importance of analysing climate-related processes for understanding expected coastal dynamics and designing targeted remediation strategies for contaminated coastal sites. Graphical Abstract The graphical summary provides a concise overview of the research, emphasizing the data utilized and the methodologies applied. It effectively synthesizes the analytical approach designed to identify areas likely to be affected by potential changes in atmospheric patterns, particularly in terms of marine bottom stress and seabed erosion processes. The visual abstract leads the reader through the following steps: first, the system under investigation is characterized by (i) analyzing climate data to assess expected changes in atmospheric variables, and (ii) defining sediment size and granulometric distribution. Then, hydrodynamic simulations are conducted to model medium-term scenarios of current intensity at both surface and bottom layers. Finally, based on simulation results, hotspot areas, ei., sites exhibiting stronger shear stresses at the sediment-water interface, are identified. These zones, prone to enhanced sediment mobilization, may also experience increased pollutant dispersion. Overall, the study demonstrates how analyzing climate-driven processes can support the analysis of future coastal dynamics and support the development of targeted remediation strategies for contaminated coastal sites.