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Sediment transport predictions are critically dependent on the prediction of near-bed wave-induced velocities. Moreover, if the determination of the suspended sediment transport is sought, it is necessary to define a velocity profile in the vertical coordinate. In this paper we present an extension of the highly non-linear Boussinesq equations to include the computation of the vertical structure of the horizontal velocity. This velocity profile is evaluated from the parabolic approximation included in the continuity equation. To verify this approach under regular waves, we include comparisons between theory and laboratory data obtained under a project known as SASME (Surf and Swash Zone Mechanics) funded by the European Union, in which the University of Plymouth was involved. In general, good agreement is found between theory and experimental data. ; La predicción del transporte de sedimentos cerca de la línea de costa depende directamente de la correcta estimación de las velocidades inducidas por el oleaje; más aún, si se desea determinar el transporte de material en suspensión, es necesario definir la distribución de velocidades en la vertical. En este trabajo se presenta el cálculo de la distribución vertical de velocidades horizontales con las ecuaciones completamente no lineales de tipo Boussinesq. El perfil de velocidades se evalúa por medio de la aproximación parabólica incluida en la ecuación de continuidad. Con objeto de verificar dicha aproximación, se incluye la comparación de los resultados obtenidos con datos experimentales de superficie libre y perfil de velocidades para el caso de oleaje regular. Las mediciones de laboratorio fueron obtenidas dentro de un proyecto europeo conocido como SASME (Surf and Swash Zone Mechanics), del que fue parte la Universidad de Plymouth. En general, se observa una buen a correspondencia entre los resultados obtenidos a través de la teoría y los de las modelaciones experimentales.

AbstractIn flood risk analysis, limitations in the multivariate statistical models adopted to model the hydraulic load have restricted the probability of a defense suffering structural failure to be expressed conditionally on a single hydraulic loading variable. This is an issue at the coastal level where multiple loadings act on defenses with the exact combination of loadings dictating their failure probabilities. Recently, a methodology containing a multivariate statistical model with the flexibility to robustly capture the dependence structure between the individual loadings was used to derive extreme nearshore loading conditions. Its adoption will permit the incorporation of more precise representations of a structure's vulnerability in future analyses. In this article, a fragility representation of a shingle beach, where the failure probability is expressed over a three‐dimensional loading parameter space—water level, wave height, and period—is derived at two localities. Within the approach, a Gaussian copula is used to capture any dependencies between the simplified geometric parameters of a beach's shape. Beach profiles are simulated from the copula and the failure probability, given the hydraulic load, determined by the reformulated Bradbury barrier inertia parameter model. At one site, substantial differences in the annual failure probability distribution are observed between the new and existing approaches. At the other, the beach only becomes vulnerable after a significant reduction of the crest height with its mean annual failure probability close to that presently predicted. It is concluded that further application of multivariate approaches is likely to yield more effective flood risk management.