Determining the mechanisms causing the hydraulic damping during ship berthing: Comprehending the water cushion effect

When a large ship enters a port the vessel is navigated by the pilots instead of the captain due to safety reasons. The final part of the berthing manoeuver is the most critical and consists of the vessel moving laterally towards the quay wall. At this point the vessel does not use its own propulsion force anymore but is pushed by the tugboats....

Crest stability of XblocPlus armoured low crested breakwaters

XblocPlus is a single layer armour unit that is recently developed by BAM Infraconsult. It is the successor of the Xbloc. An important advantage of the XblocPlus is the relatively high construction speed compared to the Xbloc. The increased construction speed is caused by the possibility to place XblocPlus in a uniform pattern and the relatively...

Assessing the impact of plastic waste accumulation on flood events with citizen observations: A case study in Kumasi, Ghana

This research assesses the impact of plastic waste accumulation on flood events with citizen observations in Kumasi, Ghana. In Kumasi, the fastest growing city in Ghana, flooding events have become more intense due to rapid urbanisation and land use intensification. Additionally, rapid population growth, urbanisation and lack of organised waste...

Modelling forces on buoyant macro plastics and their cross-sectional distribution in rivers: Simplified modelling of buoyant macro plastics according to cornerstones in behavior and particle response times in a range of riverine environments to set-up efficient monitoring campaigns and help select locations for efficient plastic removal.

Concerns regarding plastic pollution arise as large quantities of plastic enter the ocean and affect wildlife and possibly human health. Rivers form a dominant pathway for macro plastic particles into the ocean. Plastic pollution in rivers can result in blockage, where it affects water quality and ecology. This increases risks of flooding and...

Rocking of single layer armour units: Rocking revisited 3

After the failure of several large breakwaters in late 1970’s and early 1980’s where the role of rocking and breakage of armour became apparent, the importance of understanding this rocking phenomenon is given a great emphasis. Single layer randomly placed armour units are widely used in breakwater designs as they are more economical due to the...

Effects of ventilations on coastal structures with overhangs subject to wave impacts

Coastal structures with horizontal overhangs are built due to design constraints, but wave loadings substantially increase under these confined geometries. Vertical structure elements, such as steel gates, are vulnerable to damage caused by impulsive wave impacts, potentially exposing the coastal zone to flooding and erosion. Existing formulas...

Spatial and temporal trends in bed elevation and surface grain size in the upper Rhine delta and Niederrhein

This study analyzes and compares data for interventions (river training works, dredging and nourishment), discharge statistics, bed elevation and slope spatially and temporally in the Niederrhein, Bovenrijn, Pannerdensch Kanaal and Waal branches. River training works have actively taken place in the study area so far. Meander cutoffs and...

Riverine debris: interactions between waste and hydrodynamics: Field measurements and laboratory experiments for the Cikapundung River, Bandung

Plastic debris in water systems form a major problem for our ecosystem because it is extremely persistent in the environment and the global plastic production is still increasing without adequate measures to prevent pollution. Apart from the importance of reducing the amount of plastic entering the ocean, clearing the rivers from debris is...

The Bubble Barrier

Plastic pollution of our oceans is becoming a bigger problem every day. The production of new plastics is extremely cheap and convenient resulting in a lack of incentive to retrieve plastic litter. Annually 8 billion kg of plastics enter the ocean polluting the ocean environment, of which the largest part via rivers and other waterways....

A new modelling method for representing the effect of spiral flow on the bed shear stress

This thesis presents a new methodology for representing the effect of spiral flow on the bed shear stress magnitude and direction, using a low-vertical-resolution three-dimensional model. Furthermore, it discusses the performance of the new methodology in comparison with conventional high-vertical-resolution three-dimensional and depth-averaged...

Issues in Numerical Modelling and Assessing the Flow over Weirs and Groynes

In this research two problem statements are defined, namely (1) the validity of the assumption that groynes and weirs are equivalent in hydraulic models, and (2) the difficulty of modelling groynes and weirs in the 3D numerical solver package OpenFOAM. Using the incompressible 3D Navier-Stokes equations solver for multiphase phase flows, the so...

Flow patterns in partially vegetated channels: Combining physical experiments and numerical modelling

As coastal wetland ecosystems, thriving at the interface between land and water,<br/>mangroves can benefit us in lots of ways: providing food and timber, purifying water and sequestrating carbon, protecting coastal area through wave attenuation and coastal stabilization. Regarding the protection of coastal area, mangroves damp the flow in short...

Rear-Slope Revetment Stability Approached by the Wave Overtopping Simulator: Experiments Regarding the Stability of Single-Layer Cube Revetment on Breakwater Crests and Rear Slopes

Contrary to a breakwater outer slope, rear-slope revetment does not have to withstand breaking waves. However, generally, an equal dimensioned revetment is used on both the inner- and outer slope. Although with low-crested breakwaters severe overtopping occurs, the application of similarly sized armour on both sides still results in an over...

Hydraulic evaluation of longitudinal training dams

In 2015, the Dutch government initiated the ‘longitudinal training dams pilot project’. With the help of longitudinal dams, a two-channel system is created in which the river is divided into a main and a side channel. A combination of an inlet and several openings between the dams allows water and sediment to be exchanged between the two...