Video-based nearshore bathymetry estimation for Rip current forecasting on a macrotidal beach

Rip currents are seaward directed flows of water that traverse the surf zone, and in many cases pose potentially dangerous conditions for swimmers and beach users. The present study is carried out focusing on Perranporth beach, UK, which is known to present quite strong rip current events that have been the culprits of large numbers of incidents...

Rip Current Characteristics at the Dutch Coast: Egmond aan Zee

Rip currents are narrow, seaward directed flows in the surf zone that can pose a serious threat to swimmers. This issue has received attention particularly on swell dominated coasts (such as the US, Australia, France and UK) where numerous field experiments have been undertaken. However, the threat of rip currents is less recognised on wind-sea...

The reset of a subtidal bar during an energetic event: Application to Le Truc Vert beach case (France)

A large number of beach morphologies across the world exhibits nearshore sandbars with complex 3D patterns. During large storms, these shapes disappear and the bars get to a certain extent alongshore uniform. This phenomenon is called a reset. Numerous studies have been conducted on the development of the bar shapes (3D) or on the cross-shore...

Probabilistic modelling of extreme beach erosion using XBeach

The long series (>30 year) of measurement data of erosion events at Narrabeen beach (NWS, Australia) provides insight in erosion volumes and their return periods in this area. The aim of this study was to replicate these data using XBeach in order to assess the validity of both the Joint Probability Model (JPM) and XBeach on beaches such as...

Dune erosion near sea walls; XBeach validation

During a storm dunes erode and provide sediment to the beach. The foreshore rises and the wave height decreases. Subsequently the wave-induced water level setup increases. Seawalls do not erode. The waves in front of the seawall remain high throughout the storm and the wave-induced water level setup hardly changes. Over a dune-dike connection a...

Modelling Sediment Transport in the Swash Zone

The swash zone is the part of the beach that reaches from the limit of wave run-up until the limit of wave run-down. It is recognized as being a dynamic area of the nearshore region, characterized by strong and unsteady flows, high turbulence levels, large sediment transport rates and morphological changes on a small timescale. Due to the...

Low frequency wave resonance on fringing reefs

Reef systems have been estimated to exist along approximately 80% of the world’s coastlines with living coral reefs, relic limestone platforms and submerged rock formations being the most common types observed. The processes of wave breaking on a reef crest, setup on a reef and flow over and within a lagoon, have been the primary focus of...

Coastal response during the 1953 and 1976 storm surges in the Netherlands. Field data validation of the XBeach model

The storm surge early-warning system that is going to be established in the Netherlands, combines the accurate weather forecast with the hydrodynamic and morphodynamic models in an operational mode, in order to estimate the potential impact on the coasts. This study focuses on the morphodynamic validity of the operational model system, by...

Modelling the 1775 storm surge deposits at the Heemskerk dunes

After a storm surge in November 2007, older storm surge deposits were discovered in the eroded dunes near Heemskerk, the Netherlands. These deposits undulate in height with a maximum elevation of over 6 m above mean sea level. Luminescence dating suggests that the layers were deposited by either the 1775 or the 1776 storm surge. The aim of this...

Non-hydrostatic modelling of large scale tsunamis

The Indian Ocean Tsunami has once again revived the discussion in the tsunami modelling community if the non-linear shallow water equations are a valid model for the propagation of tsunamis. It is suggested that the mechanism of frequency dispersion which is absent in these equations might be important in the correct modelling of large scale...

The longshore dimension in dune overwash modelling: Development, verification and validation of XBeach

The primary objective of this thesis is to generate a 2DH-numerical model to simulate dune overwash. The first stage in this is achieved by modifying the program code of an existing overwash model in development, XBeach, to enable 2DH calculations. In the second stage the hydrodynamics of the model are verified using theoretical and laboratory...