Hydrodynamic erosion process of undisturbed clay

This paper describes the hydrodynamic erosion process of undisturbed clay due to the turbulent flow, based on theoretical analysis and experimental results. The undisturbed clay has the unique and complicated characteristics of cohesive force among clay particles, which are highly different from disturbed clay and non-cohesive sand. Based on...

SWOT analysis of breach models for common dike failure mechanisms

The use of breach models includes two tasks: predicting breach characteristics and estimating flow through the breach. Strengths and weaknesses as well as opportunities and threats of different simplified and detailed physically-based breach models are listed following theoretical and practical criteria. According to the theoretical criteria,...

Erosion due to high flow velocities: A description of relevant processes

Convential models for the erosion of non-cohesive sediments overestimate the erosion rate induced by high flow velocities. These high flow velocities occur, for instance, in breaching of embankments or dunes (flow velocities up to 10 m/s) or in jetting sand with a trailing suction hopper dredger (30 to 60 m/s). At these very large flow...

Coastal defence solutions (approach of ComCoast)

Along the North Sea coast, water levels are rising and waves are intensifying due to climate change. The best scientific evidence suggests that both phenomena are likely to accelerate over the coming decades. In some North Sea coastal areas also land is sinking and tidal heights and rates of erosion are increasing. This means that the risk of...

Advances in one-dimensional numerical breach modeling of sand barriers

A hydrodynamic numerical model is formulated to describe the breach erosion process of sandy barriers. The breach flow is based on the system of unsteady shallow water equations, which is solved using a robust upwind numerical approach in conjunction with the Finite Volume Method (FVM). The hydraulic jump is considered as part of the breach flow...

Numerical modeling of wave overwash on low-crested sand barriers

For management of coastal breaching hazards it is critical to be able to assess the potential of coastal barrier breaching as a result of wave actions during storm surges (wave overwash). This phenomenon is known as the breach initiation phase; the mechanisms behind this are not very well understood. In the present study, laboratory experiments...

A field experiment on beach growth in sand-dikes

The set-up and results of a field experiment on sand-dike breach erosion are described, It is found that the breaching process for the 2.2 m high sand-dike is similar to that in Visser's (1988) laboratory experiments with a 0.6 m high sand-dike. Confrontation of Visser's (1988) breach erosion model with the field data shows reasonable agreement...