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The advances in computational fluid dynamics have made numerical modeling a reliable complementary tool to the traditional physical modeling in the study of the wave overtopping phenomenon. This paper addresses overtopping on a seawall by combining the numerical models XBeach (non-hydrostatic and Surfbeat modes) and IH2VOF, and the Mase formulas. This work is structured in two phases: (i) phase I assesses the performance of numerical models and formulas in modeling wave run-up and overtopping on a seawall for a solid profile bottom and representative hydro-morphologic conditions of a study site in the Portuguese west coast; (ii) phase II investigates the effect of the profile bottom variation in the overtopping phenomenon for extreme maritime storm field conditions of the study site, considering a solid bottom and a varying sandy bottom. The results indicate that XBeach underestimates the wave energy, and the frequency and intensity of the overtopping occurrences predicted by IH2VOF; the numerical models' run-up and overtopping discharge predictions are overestimated by the Mase formulas, in simplified and in storm field conditions; and the variation of the bottom morphology throughout the storm event greatly influences the XBeach predictions, while the Mase results are mostly influenced by the bottom roughness. [ABSTRACT FROM AUTHOR]

Oliveira J.N.C.; Oliveira; F.S.B.F.; Freire, P., and Trigo-Teixeira, A.A., 2020. A hybrid monitoring-modelling analysis on the storm induced sediment dynamics of a structure-controlled beach. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 605–609. Coconut Creek (Florida), ISSN 0749-0208. The main objective of this study is to investigate the effect of sediment flushing on the morphology of artificially embayed beaches using field data and numerical modelling. The sandy stretch of Cova-Gala in the West Coast of Portugal, characterized by a high-energy wave climate, is critical regarding erosion-flooding risks. The site was monitored from August 2018 to February 2019, including the wave climate, the sea level and the beach topo-bathymetric elevation via sonar-single beam, GNSS-RTK and drone surveys. During this period several erosive events caused the retreat and lowering of the upper beach profile. The XBeach model was applied to simulate the morphological evolution during the monitored period using synoptic wave and sea level data as the hydrodynamic forcing. The results of the data-model analysis reveal that i) the alongshore extension of the sedimentological cells and the cross-shore structures length have a relevant influence on the lee-side erosion patterns, which affect the overall surrounding morphology, ii) the model overestimates the scouring of the seawall toe, particularly with the 1D mode; and iii) the beach backshore typology, dune and seawall, has a great influence on beach dynamic processes. [ABSTRACT FROM AUTHOR]