Modeling of wave attenuation by vegetation with XBeach

Over the past decades the effect of vegetation (e.g. kelp, mangroves, sea grass) on nearshore coastal processes has received more and more attention. In recent years several numerical wave models have been extended to include this effect. In the current study, the numerical storm impact model XBeach was extended with formulations found in...

Hydrodynamic Drivers of Sediment Transport Across a Fringing Reef

Coral reefs are highly valuable ecosystems, which are under an increasing number of environmental pressures. Sedimentation and sediment transport patterns are among key physical drivers of coral reefs, so it is important to improve our understanding of these poorly studied dynamics on reefs. To this purpose, flume experiments were performed on a...

Rip current predictions through model-data assimilation on two distinct beaches

This paper describes the development of a physics-based rip current prediction system called CoSMoS. This system consists of a hydrodynamic prediction system which is composed of a train of surge and wave models from the global scale to the scale of a beach resort (order kilometers). For the beach resort scale model, it is of utmost importance...

The influence of hydrodynamic forcing on sediment transport pathways and shoreline evolution in a coral reef environment

Improvements in spectral wave modeling in tidal inlet seas

The performance of the spectral wind wave model SWAN in tidal inlet seas was assessed on the basis of extensive wave measurements conducted in the Amelander Zeegat tidal inlet and the Dutch Eastern Wadden Sea, as well as relevant data from other inlets, lakes, estuaries and beaches. We found that the 2006 default SWAN model (version 40.51), the...

The dynamics of infragravity wave transformation over a fringing reef

A 3 week field study was conducted to investigate the dynamics of low-frequency (infragravity) wave motions over a fringing reef at Ningaloo Reef, Western Australia. Short-period wave motions (0.04–0.2 Hz) were observed to dissipate on the reef crest beyond which infragravity wave motions (0.004–0.04 Hz) gradually dominated toward the lagoon....

Online operational early warning system prototypes to forecast coastal storm impacts (cews)

Extreme coastal storms have a destructive impact on coastal areas and directly affect people living in the coastal zone, being this emphasized by recent events (e.g. Katrina, Xynthia) which reminded the world of the vulnerability of coastal areas. The economic constraints and the increasing vulnerability of coastal areas (due to sea level rise...

A field and numerical study into rip currents in wind-sea dominated environments

Rip currents are wave-induced and off-shore directed flows which occur frequently in the surf zone and can pose a serious threat to swimmers. While the behaviour of rip currents has been studied in swell-dominated environments, less is known about their characteristics in wind-sea dominated environments. This study aims to improve the knowledge...

Modelling storm impact on complex coastlines: Westkapelle, The Netherlands

Regular dune safety assessments in the Netherlands are presently based on a 1D model approach, which is insufficiently applicable for more complex coastal areas with structures, tidal channels or spatially strong varying bathymetry. These situations require more advanced methods to assess the safety in dune areas. In this study a 2DH XBeach...

Dune erosion near sea walls: Model-data comparison

This paper describes the validation of the dune erosion model XBeach with laboratory measurement data of dune erosion in the presence of sea walls and revetments. Simulation results show that the essential dune set back processes are captured by the model and that the measurements at most locations are approximated quite well. Some aspects...

Using 18th century storm-surge data from the Dutch Coast to improve the confidence in flood-risk estimates

For the design of cost-effective coastal defence a precise estimate is needed of the 1/10 000 per year storm surge. A more precise estimate requires more observations. Therefore, the three greatest storm surges that hit the northern part of the Holland Coast in the 18th century are reconstructed. The reconstructions are based on paintings,...

The effect of the longshore dimension on dune erosion

The effect of the longshore dimension on dune erosion is examined numerically with a 2DH process based model XBeach. Exploratory simulations are presented to examine longshore effects due to directionally spread waves, longshore variation in topography and longshore variation in bathymetry. The simulations reveal that alongshore sediment...

Short wave breaking effects on low frequency waves

The effect of short wave breaking on low frequency waves is investigated using two breaker formulations implemented in a time-dependent numerical model (XBeach): (1) an advective-deterministic approach (ADA) and (2) the probabilistic breaker formulation of Roelvink (1993). Previous research has shown that the ADA breaker model gives different...

Shoaling and shoreline dissipation of low?frequency waves

The growth rate, shoreline reflection, and dissipation of low?frequency waves are investigated using data obtained from physical experiments in the Delft University of Technology research flume and by parameter variation using the numerical model Delft3D?SurfBeat. The growth rate of the shoaling incoming long wave varies with depth with an...

Coastal inlets and tidal basins

lecture note: Tidal inlets and their associated basins (lagoons) are a common feature of lowland coasts all around the world. A significant part ofthe world's coastlines is formed by barrier island coasts, and most other tidal coasts are interrupted by estuaries and lagoon inlets. These tidal systems play a crucial role in the sediment budget...

Numerical Modelling of Infragravity Wave Response during Delilah

In this paper the nonlinear numerical model SHORECIRC is applied to simulate the intragravity wave conditions on two days during the 1990 Delilah campaign. In order to simulate the wave conditions an algorithm has been derived which synthesizes a directional of/shore wavefield from data including the bound, directional low-frequency components....

Directional spreading in surfbeat: A first assessment

In the following we consider the forcing of long waves by normally or obliquely incident grouped short waves, also known as surf beat. Two mechanisms responsible for the generation of long waves are considered: the release of the bound long waves associated with changes in the spatial variation of the incident short wave energy [Longuet-Higgins...