Detailed simulation of morphodynamics: 3. Ripples and dunes

We present a 3-D physics-based high-resolution modeling approach to the dynamics of underwater ripples and dunes. The flow is modeled by large eddy simulation on a Cartesian grid with local refinements. The sediment transport is modeled by computing pickup, transport over the bed, transport in the water column, and deposition of rigid spherical...

Physics of Blown Sand and Coastal Dunes

The interaction between bed-load transport and dune orientation

Bedforms play an important role in the sediment transport of a river. Because of their importance many experiments have been carried out to better understand bedforms. Most experiments concern transverse bedforms (with crests aligned perpendicular to the flow direction). However, bathymetry measurements show many instances of oblique dunes....

Process-based modeling of coastal dune development

In this paper, the aeolian transport model DUNE (Sauermann et al., 2001, Kroy et al., 2002) that describes important features and dynamics of typical desert dunes, is extended such that it can be applied in sandy coastal areas. Initial tests explore the limitations of the model in coastal areas after which adaptations are proposed and...

Process-based Modeling of Coastal Dune Development

This thesis presents the application of an aeolian transport model used in desert environments [Sauermann et al., 2001, Kroy et al., 2002] as a tool for the evolution of coastal nourishments. This study will try to investigate the driving processes in the model and adapt or extend the model application to the coastal system. If we want to apply...

A model for breach growth in a sand-dike and its prediction for the Zwin 94 experiment

A mathematical model for breach growth in sand-dikes and dunes is described. The model is based on the five-step breach erosion process as observed in several laboratory experiments and the Zwin 89 field experiment. A simplified Galappatti (1983) pick up mechanism for sand from the bed is combined with Bagnold's (1963) modified (Visser, 1988)...

Water movement over a horizontal bed and solitary sand dunes

In order to predict waterlevel changes in rivers due to floodwaves and local bedshapes for navigation, the local behaviour of the riverbed should be known . In many cases the bed of 3 river consists of dunes, which propagate downstream due to the sediment transport along the dunes . In this report mainly the watermovement but also the sediment...

Sand stabilization and dune building

The growth of dune vegetation can be stimulated by the application of suitable fertilizers. Newly planted seedlings and sparse vegetation on the sea dunes can be very much improved by this means, provided the quantity of windblown sand is not excessive. Otherwise sand fences have to be constructed for stabilization purposes. Marram grass and...