Field Observations of Infragravity Waves off the Dutch Coast

Infragravity (IG) waves (0.005-0.04 Hz) are surface waves that can dominate the nearshore hydrodynamics and can impact various coastal processes (e.g., run-up, overwash). A proper offshore description of incident IG waves is required for storm impact models, which generally assume a local equilibrium between sea-swell (SS) waves (0.04-0.33 Hz)...

A new installation technology of large diameter deeply-buried caissons: Practical application and observed performance

The development of installation technologies of open caissons has been lagging behind increasingly complex construction conditions. For such purpose, a new installation technology of large diameter deeply-buried (LDDB) open caissons has been developed and then used for construction of twin LDDB caissons into undrained ground with stiff soils...

Editorial: Coastal protection provided by ecosystems: Observations and modeling across scales

Bayesian Inference of Piping Model Uncertainties Based on Field Observations

This paper presents a Bayesian model to determine the model uncertainty of a critical horizontal gradient model for piping for dikes, such a Lane and Bligh. A Bayesian model is needed for two reasons. First, there is a large overlap in cases that failed and survived. Second, the evidence of the failed cases is limited .The model consists of a...

Integral Failure Analysis of Pipelines in Flood Defenses

The presence of pipelines in flood defenses presents a challenge for assessing the probability of flooding. To prevent costly structural measures compensating for the possible negative effects of pipeline failure, we developed a framework for an integral failure analysis of pipeline and dike failure. The assessment framework is based on an event...

Pre-cracking development of weld-induced squats due to plastic deformation: Five-year field monitoring and numerical analysis

Weld-induced squats are a major damage type in high-speed railways as well as in conventional railways. They incur high maintenance costs and endanger operational safety. This paper first presents and analyzes five-year continual field monitoring observations and measurements of squats at rail welds. A hypothesis of the formation and development...

The challenge of parameter uncertainty: Finding parameter distributions from hydrological field data for conceptual rainfall-runoff models

Conceptual hydrological model parameters represent characteristics of a catchment. They are an integration of spatial heterogeneous parts of the system. Finding adequate parameter values based on field observations, which represents the heterogeneity of a catchment on the spatial resolution and scale of the model, is considered challenging since...

Observations of Time-Dependent Bedform Transformation in Combined Wave-Current Flows

Although combined wave-current flows in the nearshore coastal zone are common, there are few observations of bedform response and inherent geometric scaling in combined flows. Our effort presents observations of bedform dynamics that were strongly influenced by waves, currents, and combined wave-current flow at two sampling locations...

On reducing piping uncertainties: A Bayesian decision approach

Dikes and levees play a crucial role in flood protection in deltaic areas such as the Netherlands. Internal erosion piping or under-seepage is a major cause of levee failures and a main contributor to the probability of failure of river levees due to the large (mostly geotechnical) uncertainties. The present thesis investigates how geotechnical...

Advances in reliability analysis of the piping failure mechanism of flood defences in the Netherlands

Piping is one of the main failure mechanisms for flood defences. This paper gives an overview of recent developments in the reliability analysis for this mechanism in the Netherlands. These comprise new approaches in the treatment of heterogeneity of the subsoil with respect to the failure process, the inclusion of information from field...

Observations and modeling of steep-beach grain-size variability

Novel observations of surface grain-size distributions are used in combination with intra-wave modeling to examine the processes responsible for the sorting of sediment grains on a relatively steep beach (slope?=?1:7.5). The field observations of the mean grain size collected with a digital camera system at consecutive low and high tides for a 2...

A field 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...

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...

Scour around an offshore windturbine

During the construction of the first Dutch offshore wind farm prototype measurements were performed. These measurements were aimed to monitor the behaviour of the granular filter layer of the scour protection around the mono-piles upon which the wind turbines are founded. These measurements were compared to scale model test results and...

On Internal Waves in a Density-Stratified Estuary

In this article some field observations, made in recent years, of internal wave motions in a density-stratified estuary are presented, In order to facilitate the appreciation of the results, and to make some quantitative comparisons, the relevant theory is also summarized. Furthermore, the origins of stratification in estuaries is briefly...

Analyse brandingsstroommetingen nabij Joossesweg (Westkapelle)

In de periode maart tot april 1985 heeft de Adviesdienst Vlissingen enige brandingsstroommetingen uitgevoerd voor de kust van Walcheren ter hoogte van Joossesweg (nabij Westkapelle). Het doel van het meetonderzoek is het verkrijgen van meer inzicht in de veranderingen die optreden op een gesuppleerd strand ten gevolge van stroom en golven. Met...