Testing storm impact modelling at São Pedro de Moel beach

• Autor(a) principal: Cabrita, Paulo Sérgio Faustino
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/15292
• topic: Xbeach; Swan; Galgamento; Formula empírica; Evolução da praia; Tempestade costeira; Domínio/Área Científica::Ciências Naturais::Outras Ciências Naturais

Numerical models are very powerful tools to predict the effects of the extreme conditions associated with coastal storms. The main objective of this work was to simulate the effects of coastal storms in São Pedro de Moel beach, in terms of overtopping and morphological evolution associated, by using XBeach. To simulate the coastal storms using XBeach, it was necessary to have the data regarding the nearshore sea state. This was obtained by propagating offshore wave data conditions to nearshore using the SWAN model. The XBeach model was divided into two setups to analyse two different situations, overtopping events (non-hydrostatic setup) and coastal evolution (surf beat setup). Sensibility tests were performed for both setups testing different model parameters. The model was also, calibrated and validated using information from past storms. The non-hydrostatic setup demonstrated sensibility to the bathymetric resolution and for the intrinsic model parameters related to the bed friction and the non-hydrostatic correction. The results from the XBeach simulation of the overtopping event were compared against results from an empirical formula (Mase et al., 2013), which simulates the overtopping events associated with a seawall. The comparison of results showed lower values obtained with the empirical formula. The surf beat setup demonstrated sensibility to the bathymetric resolution, and the intrinsic model parameters related to wave dissipation, sediment transport and morphology. The results from the calibration and past storm simulation of the coastal evolution setup point out to the necessity of having better field data before and after storms to improve the model settings and accuracy.