Aeolian morphodynamics on a humid tropical coastal dune field in Itaúnas, Brazil: insights into system dynamics and implications for coastal management

Abstract Coastal dune fields developed under humid tropical conditions exhibit complex aeolian morphodynamics controlled by climatic variability, vegetation cover, sediment availability, and anthropogenic disturbance. In the Itaúnas region, southeastern Brazil, the anthropogenic removal of vegetation cover since the 1950s intensified the transgressive migration of mobile dunes across the coastal plain, affecting urban infrastructure, surface water resources, and permanent environmental preservation areas. This study investigates the aeolian morphodynamics of the Itaúnas coastal dune field through a multiproxy approach that integrates geomorphological, sedimentological, meteorological, and remote-sensing data, along with three-dimensional terrain analysis and satellite imagery. The investigated aeolian system covers approximately 600,000 m², of which about 310,000 m² correspond to mobile dunes. Granulometric analyses, topographic profiles, and aeolian transport indices indicate that, despite the limitations imposed by the humid tropical climate, significant aeolian activity occurs, especially during the dry season, particularly in the central sector of the dune field. The results highlight the influence of vegetation cover, wind regime, grain size, and sediment availability on dune mobility and morphological organization. This study contributes to a broader understanding of coastal aeolian dynamics under humid tropical conditions and provides scientific support for coastal management strategies. The findings provide scientific support for environmental management, territorial planning, and coastal management strategies aimed at mitigating geological and environmental risks associated with dune migration in environmentally sensitive and urbanized coastal areas.