Evolutionary trends of aeolian morphodynamics under natural and anthropogenic influences in the Coastal Region of Northeastern Brazil

Abstract

Coastal dune systems are increasingly affected by land use changes and urbanization, which alter aeolian morphodynamics and reduce sediment supply. This study investigates the multidecadal evolution of a coastal dune system in northeastern Brazil, comparing a period of minimal human influence (1958–1970 s) to one marked by significant anthropogenic intervention (1980s–2025). A multitemporal approach combining remote sensing, field surveys, sedimentological and geochemical analyses, and climatic data was applied. Results show a transition from a highly dynamic transgressive landscape to a progressively stabilized system. Historically, sediment supply from the beach maintained active dune dynamics, especially during dry and windy periods. However, sediment input has declined since the 1970s due to natural processes such as foredune stabilization and shifting wind regimes, with a sharp acceleration following infrastructure development and urban expansion. This sediment deficit triggered the remobilization of existing aeolian deposits, leading to localized blowouts and partial dune activity. Despite this, aeolian processes became increasingly confined to the foredune zone, even in areas with minimal direct human impact. Grain size and compositional data indicate well-sorted aeolian sands influenced by both marine contributions and vegetation-induced stabilization. The findings highlight the combined influence of climatic variability and human intervention in shaping dune system evolution. While the long-term trend of declining sediment transport from the beach persisted regardless of human presence, anthropogenic impacts accelerated the confinement of aeolian activity to the foredune zone.

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