Free Infragravity Waves and their Effect on Coastal Dune Safety

The coastal safety of the dunes are of high importance for low laying countries (Chen et al., 2017). This is especially true for the Netherlands as it is used officially as a safety measure against flooding from extreme weather since 1984 (Rijkswaterstaat, 1989). As of current 1D modelling of the waves is an acceptable method for the Dutch coast...

Infragravity wave resonance over coral reef lined coasts

Coral reefs are vital to the prosperity of the world and the local communities by providing food and coastal protection. Coral reefs are home to 25% of marine life and have therefore gained the nickname ’rainforest of the sea’. However, the reefs are being damaged by climate change and human intervention, resulting in an alarming rate of...

Infragravity waves on the North Sea: Generation, propagation and dissipation mechanisms

Recent analysis on measurements in the North Sea has shown a large amount of wave energy ranging in infragravity bands in the North Sea during storm events. To better understand the generation and propagation of free infragravity waves, the SWAN model is used to inspect the infragravity wave pattern, the infragravity wave origins, and the...

Impact of Free Long Waves on Dune Erosion Predictions in Numerical Modelling

This report presents the methodology and findings of a study on the impacts of free long waves on dune erosion predictions in XBeach. In this paper a distinction is made between two types of infragravity waves: bound infragravity waves and free infragravity waves. Bound infragravity waves are generated by short-wave group forcings and are bound...

Mapping port operability indicators across the world: Screening the suitability of port locations related to metocean conditions

Long waves in the North Sea: Distribution, generation and measurement methods

This report presents the results of a research concerning long waves in the North Sea. ‘Long waves’ in this research is a collective name for various types of waves that are longer than the well-known sea-swell waves, here referred to as ‘short waves’. Wave types that are referred to as long waves are infragravity waves, meteo-tsunami’s, seiches...

The effect of a shallow vegetated foreshore on infragravity waves: A study with SWASH

A specific type of wave is identified as an infragravity wave (IG wave). These waves with very long wave periods, even up to minutes, are possibly dangerous for flood events, increased storm surge and/or failure of coastal defences. Current guidelines for dike safety are often determined for gravity wave dominated systems, so identifying IG...

The influence of incident waves on runup: A comparison between a phase-averaged and a phase-resolving XBeach model

Wave runup is generated by energy which remains after wave breaking and travels farther to the coast in the form of a bore. It can be seen as a thin wedge of water running up the beach face (Brocchini and Baldock, 2008). Under storm conditions runup is responsible for beach and dune erosion and accurate runup predictions are therefore required ...

A method to calculate the probability of dike failure due to wave overtopping, including the infragravity waves and morphological changes

In this thesis, a method was developed, with which the infragravity waves and morphological changes of a sandy foreshore are included in the calculation of the probability of dike failure due to wave overtopping. Constructing a natural foreshore in front of the dike can be an attractive and innovative method to decrease the failure probability....

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...

Numerical modelling of infragravity waves in coastal regions

Infragravity waves are a common feature in the nearshore wave field and have a significant impact on numerous coastal processes. It is therefore important to accurately predict infragravity wave conditions at a given location. However, analytical relations do not exist with which to make such predictions and one has to rely on numerical models....

Low Frequency Waves in the Shoaling and Nearshore Zone

It has been found by many researchers that low frequency (LF) waves dominate the wave energy spectrum in very shallow water. Given that many longshore and cross-shore morphological processes are located within this zone, LF waves play an important role in determining morphological change, especially dune erosion and overwash during storm events....