Influence of Sandy Foreshores on Overtopping in Non-Tidal Low-Energy Shallow Lake Environments

Sea level rise will increase the risk of flooding in coastal areas. This poses a risk to the coastal protection as well as rivers and lakes close to the coast. Solutions are needed to cope with this threat. The past decade, nature based solutions have gained significant interest. One of these solutions could be sandy foreshores. Due to the use...

Computing breakwater stability using SWASH: The effects of model choices, shallow foreshore and oblique waves on the stability of a rubble mound breakwater

On the east coast of Romania, at Eforie, coastal erosion manifests. To strengthen the coastal area a large coastal protection project was setup involving beach nourishment combined with the construction of breakwaters. The breakwaters are designed with the well-known modified Van der Meer formulas. To ensure confidence in the breakwaters...

Climate Adaptation of Rubble Mound Breakwaters: A study to the accuracy of overtopping formulas for combination of solutions

Rubble mound structures are often constructed to prevent severe wave damage to ships. By constructing the crest at a certain level, the waves are reduced such that safety is ensured. However, a large increase in sea level rise is expected in the next century due to climate change. Because of this, multiple adaptations might be necessary to meet...

Foreshore Morphodynamics from Shore-based Marine Radar: On a Stretch of Sylt Beach

Bathymetry strongly affects nearshore hydrodynamics that drive sediment transport. However, recent bed level information is not always available, especially not simultaneously resolved in space and time. Time series of radar backscatter images can be used to retrieve bed levels in the intertidal area with the so-called Temporal Waterline...

Effects of the foreshore and heterogeneities of the subsoil on the safety analysis of piping

In this thesis, the effects of the foreshore and heterogeneities of the subsoil on the piping safety analysis are determined. The effects are searched for by use of the numerical model D-Geo Flow. The results of this research give more insights in when and how a foreshore has to be included in the safety analysis. It is also concluded that...

Global Flood Hazard Reduction by Foreshore Vegetation

Global flood exposure simulations show that about 600 million people, of which 320 million in urban areas, are at risk to the impacts of global sea-level rise and changing storm intensity and frequency. Increasing availability of data and computational efficiency enables to assess flood hazard on a global scale. Implementation of salt marshes...

Safety assessment method for macro-stability of dikes with high foreshores

This Thesis studies the safety assessment method for macro-stability of dikes with high foreshores. Currently, this method is a semi-probabilistic method, which does not take the presence of a foreshore into account. The research concludes that the presence of a foreshore has a significant influence on the failure probability with respect to...

Wave Transformation on Shallow Foreshores: A Study with SWAN and SWASH

Across the world, the presence of humans in coastal regions is always increasing. Hydraulic forcing from extreme events is a large risk around the global coastlines, the risk being complicated by the increased human presence along the coasts.<br/>The knowledge that vegetation can be used as a coastal protection measure is not something new. The...

Foreshores in the Wadden Sea

Dutch flood protections are assessed every five to six years in a nationwide safety assessment round. During the last assessment round large dike stretches in the Dutch Wadden Sea could not meet the safety requirements, and were assessed with failure. Dike strengthening is therefore needed in these areas. However, in front of these dike salt...

Wave-induced stem breakage in a vegetated foreshore and its implication on probability of flooding

Various flood protection measures are studied across the globe, and nature-friendly and environmentally resilient methods are gaining more attention. As part of the building with nature initiative, the project BE SAFE (Bio-Engineering for SAFEty) studies the effects of a vegetated foreshore as a flood protection measure which is found to be very...

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....

Nourishing intertidal foreshore: Improving safety and nature

After extensive flooding in 1953, Deltaworks were constructed to protect the Southwest delta in the Netherlands. In the Eastern Scheldt the connection to the North Sea was regulated by an open storm surge barrier and two compartment dams. These decreased the tidal volume and consequently tidal flats are eroding and disappear under water. The...

Stability of rock on slopes under wave attack: Comparison and analysis of datasets Van der Meer [1988] and Van Gent [2003]

In VAN GENT [2004] graphs were presented in which the datasets of VAN DER MEER [1988] and VAN GENT ET AL. [2003] were compared, but in this comparison a number of parameters were not correctly transformed into a comparable format. In this M.Sc. thesis after an extensive analysis to the datasets all parameters of the datasets of Van der Meer were...

Versteiling van de Hollandse kust nader bekeken: Een statistisch onderzoek naar de doorlodingsnauwkeurigheden voor het verkrijgen van meer zekerheid omtrent de versteiling van de diepe vooroever

Eerdere onderzoeken naar de bodembewegingen van de diepe vooroever van de Hollandse kust hebben aangetoond, dat er zodanige zandverliezen optreden, dat er sprake is van versteiling. Versteiling is het fenomeen, waarbij het profiel zich niet gedraagt als een vormvast evenwichtsprofiel, maar zich ontwikkelt naar een steiler profiel. Dit kenmerkt...

De waterbeweging in het Sieperdaschor

Het Sieperdaschor is ontstaan uit de voormalige Selenapolder, nadat in februari '90 tijdens een zware storm de zomerkade is doorgebroken. Reparatie bleek te kostbaar en daarom is in overleg met Zeeuws Landschap besloten om de dijk niet te herstellen. Dit bood een goede gelegenheid om de ontwikkeling van polder tot schor te onderzoeken. Dit mede...

Golfoploop op dijken met ondiep voorland

kruinhoogte. Een te lage dijk kan onder extreme omstandigheden bezwijken, waarna inundatie van het achterliggende land volgt. Een te hoge dijk daarentegen betekent dat onnodig hoge aanlegkosten. Het is dus van groot belang de benodigde kruinhoogte van een dijk nauwkeurig te kunnen bepalen. Twee belangrijke faetoren die de benodigde kruinhoogte...

Shallow foreshore wave height statistics

Wave height distributions on shallow foreshores deviate from those in deep water due to the effects of the restricted depth-to-height ratio and of wave breaking. Laboratory data of wave heights on shallow foreshores of different slopes have been analysed to determine these effects and to derive generalised empirical parameterisation. A model...

Golfvervorming bij een hoog voorland

Het rapport "Literatuuronderzoek bij een hoog voorland" bevat een systematische weergave van de bestaande kennis van het gedrag van golven in een bepaalde ondiepte-situatie. Die situatie betreft een tamelijk vlak, relatief hoog liggend voorland voor een kust met daar boven een geringe waterdiepte, en wel het gebied vanaf de lijn waar de golven...