Journal of Waterway, Port, Coastal, and Ocean Engineering

Analytical solutions to an extended version of the one-line model for shoreline change are derived in this paper for two cases: (1) shoreline change when the evolution of an alongshore position is a known function of time; and (2) shoreline change within a groyne compartment. The solutions extend existing analytic approaches by accounting for arbitrarily time-varying wave conditions. Explicit solutions are obtained by means of integral transform techniques. The generalized expressions can account for time-varying wave conditions, for an initial beach shape which is an arbitrary function of position, and for sources/sinks of sediment that are a known function of time and space. Example applications are described and the impact that a time-varying wave forcing can have on beach development is investigated. In contrast to previous analytic work, changes in shoreline evolution rate in response to the continuously changing wave conditions in a time series are revealed. Apart from being a more realistic tool for a fast preliminary estimation of long-term shoreline change, the new solutions are also a valuable independent means for validating numerical one-line models.

In this paper the relevance of different driving terms that contribute to the winter circulation in the Barcelona Harbor are analyzed. Data from a field campaign are analyzed in order to characterize the most relevant hydrodynamic events. This field campaign covers wind, waves, currents, and water quality parameters under winter conditions (Nov–Dec 2003). These events are related to the velocity response at a control point inside the harbor. Characteristic scenarios are simulated through numerical modeling in order to obtain the corresponding velocity field in the studied domain. The characteristic measured events and the numerical results are compared for velocity and show reasonable agreement under similar conditions. According to these results, the wind- and wave-driven circulations seem to control winter circulation in the Barcelona Harbor. The results obtained increase the knowledge of harbor hydrodynacmics and could be used as a tool to solve certain water quality problems in the Barcelona Harbor.

This paper reviews transformation processes and nonlinear properties of internal waves over a uniform slope in a two-fluid system, attempting to reveal water particle kinematics by using particle image velocimetry (PIV). Attenuation and setup induced by wave breaking are predicted using an energy-dissipation model including the radiation stress. In the present paper, the radiation stress is associated with the time-averaged momentum flux owing to the interaction between incident and reflected internal waves. These predictions agree with experimental data obtained by an image processing technique with which the boundary plane between the upper and lower layers could be detected as a density interface. A set of halogen lamps and three high-definition digital video cameras are used to illustrate velocity vector fields during one wave period. Instantaneous velocity fields measured by the PIV system are compared with the calculated velocity distribution by the method of characteristics in combination with the first-order Stokes theory. The rundown behavior is then investigated, and its influence upon the undertow in the lower layer is explained with a simple turbulent-jet model. Furthermore, the theoretical approach for examining mass transport and undertow is discussed in relation to the measured mean velocity.

This work discusses the implementation and validation of the SWAN model forced by NCEP/NCAR reanalyzed 10 m winds in the outer Río de la Plata (RDP) and adjacent continental shelf that will be used to study the wave climate in the region. Thirteen-month-long in situ data series of wave parameters are used to validate the results from numerical simulations. A set of numerical experiments is carried out in order to find a suitable computational domain to generate realistic simulations in the mouth of the RDP estuary. Numerical experiments including current and sea level fields are run, demonstrating that simulated wave parameters at the outer RDP are not significantly improved. A correction coefficient, dependent on wind speed, is applied to the wind drag factor in order to minimize the differences between simulated and observed wave parameters. The relatively low resolution wave model that satisfactorily simulates in situ wave heights and directions but slightly underestimates periods is a reliable tool for future applications and investigations.

The data processing required to extract long waves from tide-gauge data is described and applied to three diverse but typical examples: meteorologically generated long waves (rissaga), far infragravity waves, and tsunami. The steps are: detiding, despiking, degapping, high-pass filtering, and denoising. Orthogonal wavelet decomposition is used for despiking, high-pass filtering, and denoising. This has the advantage that it can be used for nonstationary data such as rissaga and tsunami because the basis function (the mother wavelet) is localized. The long-wave extraction method has evolved from development of real-time systems for monitoring long waves for navigation purposes. Using the technique, there are hundreds of modern tide gauges around the world (every major port has one) whose data could be used to monitor long waves that affect navigation and cause a hazard.