Abordagem multiescalar da variação energética de ondas e a resposta de praias de Marataízes, ES

• Ano de defesa: 2023
• Autor(a) principal: Eguchi, Branco Mateus Murata
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Doutorado em Oceanografia Ambiental; Centro de Ciências Humanas e Naturais; UFES; Programa de Pós-Graduação em Oceanografia Ambiental
• Palavras-chave em Português: Ondas extremas; Refração; Difração; Antepraia; Grau de exposição à energia de ondas; Mobilidade praial; subject.br-rjbn; Ciências Ambientais
• Link de acesso: http://repositorio.ufes.br/handle/10/16878

How to deal with the different time and space scales of coastal processes is a major concern in evaluate coastal impacts. In order to better comprehend these processes, it is important to understand the energy input in regional scale, such as waves and tides, and how local coastal features are able to modify this input. Despite the focus on local coastal processes, this thesis is based on series of replicable methodologies, aiming to characterize coastal processes and vulnerability in different time and space scales. First step was to determine oceanographic energy inputs for the whole region, for example, waves, astronomical tide and extreme waves. Moreover, a correlation between extreme waves parameters and the modes of climate variation El Ninõ Southern Oscillation (ENSO) e Southern Annular Oscillation (SAM). The second part of the thesis regarded to determine the effects of local ocean floor morphology on wave energy and how beaches respond to these variations. Also, a coastal susceptibility index was proposed based on wave energy variations and beach responses. Lastly, the impacts of a storm were quantified comparing beach profile changes before and after. Wave climate showed a bimodal pattern with easterly waves related to good weather and southeasterly waves associated to storms. Extreme waves presented significant height and duration of 1,72 m and 48 h, respectively. The highest values of extreme wave energy, duration and quantity occurred during neutral phase of ENSO and negative phase of SAM. In contrast, the lowest values occurred during the positive phase of both modes simultaneously. Easterly waves showed a pattern of energy increase of 30% as they propagate from deep to shallow waters. Waves coming from southeast also presented an increase of wave energy, but of only 9%. In general, all post-storm beach profiles showed no major impacts. In conclusion, extreme wave season begins in July and peaks in September. Extreme waves change from highly energetic and lasting, in early season, to more frequent but briefer, late in the season. Wave energy dissipation at shallow waters occurs differently along the coast. In the long term, beach profiles may not be able to resist to storm impacts.