Estudo da morfodinâmica e variabilidade sazonal da praia de Zalala com uso de drones e dados meteoceanográficos

Abstract

Beach morphodynamics refers to the dynamic interactions between hydrodynamic processes, such as wave propagation and breaking in shallow waters, and the morphological response of different beach subenvironments (based on sedimentation), across a variety of spatiotemporal scales. These interactions become increasingly complex with additional processes, such as tides and winds, and different boundary conditions, including antecedent beach morphology, sediment characteristics, and biota. This study explores the morphodynamics of Zalala Beach based on topographic data derived from aerial surveys using the DJI Mavic 3 drone and meteoceanographic data. The results indicate that Zalala Beach alternates between two morphodynamic stages: A dissipative stage, occurring during the winter months, characterized by high, slender waves (storm conditions). An intermediate "longshore bar and trough" stage, observed during the summer months, a period with lower energy levels. During this phase, swash on the beach face is relatively high, with the formation of erosional features that are less pronounced, alongside depositional features associated with shorter, low-energy waves. The climatological analysis of average monthly wind speeds showed no significant variation in wind intensity throughout the year. This suggests that the seasonal morphological variations at Zalala Beach are associated with the frequency of storms, which are more prevalent in winter. Tides play a significant role in sediment transport along Zalala Beach, moving sediments transversally from dunes to the beach and vice-versa.