Onshore sandbar migration in the nearshore

This thesis is about the hydrodynamic processes that occur when a nearshore sandbar migrates towards the shore driven by the waves. These processes are relevant because process-based morphological models have difficulty simulating coastal accretion events in contrast to erosion events. Simulating accretion events is important for engineering...

Wave Generation of Gravity-Driven Sediment Flows on a Predominantly Sandy Seabed

Wave-supported gravity flows (WSGFs) generate rates of sediment flux far exceeding other cross-shelf transport processes, contributing disproportionately to shelf morphology and net cross-shelf fluxes of sediment in many regions worldwide. However, the conditions deemed necessary for the formation of WSGF limit them to a narrow set of shelf...

Cross-shore stratified tidal flow seaward of a mega-nourishment

The Sand Engine is a 21.5 million m³ experimental mega-nourishment project that was built in 2011 along the Dutch coast. This intervention created a discontinuity in the previous straight sandy coastline, altering the local hydrodynamics in a region that is influenced by the buoyant plume generated by the Rhine River. This work...

Cross-shore transport of nearshore sediment by river plume frontal pumping

We present a new mechanism for cross-shore transport of fine sediment from the nearshore to the inner shelf resulting from the onshore propagation of river plume fronts. Onshore frontal propagation is observed in moorings and radar images, which show that fronts penetrate onshore through the nearshore and surf zone, almost to the waterline....

Near-Bottom Currents on the Middle Shoreface in the Presence of the Rhine River Plume

The South-Holland coast of the Netherlands undergoes the influence of the Rhine river plume released from the Rotterdam waterways. An experiment, STRAINS, was conducted to study the impact of the fresh water on the nearshore hydrodynamics and sand transport. As part of the experiment, an instrumented bottom frame measured the near-bed...

Near-bottom currents on the middle shoreface in the presence of the Rhine River plume

The South-Holland coast of the Netherlands undergoes the influence of the Rhine river plume released from the Rotterdam waterways. An experiment, STRAINS, was conducted to study the impact of the fresh water on the nearshore hydrodynamics and sand transport. As part of the experiment, an instrumented bottom frame measured the near-bed...

Spatial variability of the wave bottom boundary layer over movable rippled beds

Observations of the spatially dependent velocity field over movable bed forms subjected to slightly skewed and asymmetric regular wave forcing were collected. The dynamics between the ripple elements is dominated by coherent vortices, characterized by the swirling strength, and evidenced in the temporal and spectral characterization. Within the...

The IPG BAR project

The booklets 'Making Patterns' and 'Using Patterns' describe two aspects of the the pattern method within the urban design process. The accompanying IPG BAR Pattern Library is a small pattern library of urban-airport symbiosis patterns. These documents are the result of the Interdisciplinary Project Group “Better Airport Regions” MSc Industrial...

Monitoring morphology of the sand engine leeside using Argus' cBathy

The Sand Engine is a mega-nourishment constructed in 2011 with the purpose of replenishing the surrounding southern Dutch coast by exploiting the strength of local alongshore currents for the next 20 years. Long term monitoring of the Sand Engine depends upon remote sensing coupled with in-situ measurements due to both its large spatial and...

The sand engine: A solution for vulnerable deltas in the 21st century?

The Netherlands’ strategy to combat coastal erosion since 1990 has been through nourishment, initially as beach nourishments but more and more as shoreface nourishments. In the light of sea level rise projections the yearly nourishment magnitudes continue to increase. In view of this an innovative soft engineering intervention, comprising an...

Vortex tubes in the wave bottom boundary layer

The cause of sediment suspension events during flow reversal under waves in the nearshore is not well understood. Vortex tubes and horizontal pressure gradients have been suggested to be the cause of the suspension events. A medium sized wave flume experiment has been conducted to give insight in the hydrodynamics of the wave bottom boundary...

Wave boundary layer hydrodynamics during onshore bar migration

To study onshore bar migration and the accompanying intra-wave sediment transport a wave flume experiment was conducted. The wave flume had a rigid bottom with a single bar profile. The focus of the experiment was to measure the hydrodynamics in the wave bottom boundary layer. The results show that the skewness of bottom stress is not only...

Surf zone surface retention on a rip?channeled beach

The retention of floating matter within the surf zone on a rip-channeled beach is examined with a combination of detailed field observations obtained during the Rip Current Experiment and a three-dimensional (3-D) wave and flow model. The acoustic Doppler current profiler–observed hourly vertical cross-shore velocity structure variability over a...

Surfing waves generated by a hull

In this paper a new wave pool concept is presented using ship hulls as wave generators. To evaluate the potential of such a concept a towing tank experiment is conducted to investigate ship wave generation in a confined space. In the towing tank experiment various hull sizes and velocities are examined to maximize the generated wave height. The...

On the scaling of sediment transport in the nearshore

Scale relations are necessary to choose proper sediment for physical models. The use of lightweight artificial sediment makes it possible to preserve the Reynolds number, Shields number and relative settling velocity altogether. There is also the possibility to preserve the Shields number in combination with the Dean number which would be more...