Avaliação da influência de eventos de alta energia ligados a sistemas atmosféricos do hemisfério norte sobre o balanço sedimentar da Praia do Meireles, Ceará

Abstract

Considering the high dynamicity of atmospheric and oceanographic variables in coastal processes, local sedimentary balance is a matter of great interest for Integrated Coastal Zone Management. The diversity of environmental factors as well as the topographic variations related to storm surge events associated to cyclone formation in the North Atlantic are assessed in this research for a stretch of the Meireles Beach, Fortaleza, Ceará. For this purpose, an association of direct and indirect methods was applied for data acquisition and processing. Remote sensing techniques with Unmanned Aerial Vehicle (UAV), 3D modelling and sedimentary analysis were performed, as well as detailed monitoring of meteorological and oceanographic variables with in situ sources and environmental modelling. The results of one-year monitoring revealed a sedimentary balance with different variations in response to high-energy events associated to extratropical cyclones on the North Atlantic. The sedimentary balance showed an erosional rate of 25.5%, reflected in a 17.4% diminution in average topographic level of the area. Beach erosion was correlated to long period waves and great variability of wave types. Positive volumetric changes were correlated to mild weather environmental conditions. Swell waves presented a significant role in both beach erosion and following consequential topographic recovery. There was an asymmetric susceptibility to volume losses in different beach sectors. Future perspectives of continuous high-quality monitoring, such as the one performed in this study, are a factor of great relevance for the study area – and for a global scenario which reflects the increasing anthropization of coastal zone.