Modelling morphological changes over time scales of decades to centuries: a review

Water Qualit

Sediment modelling for Poole and Christchurch Bays

Hydrodynamic

Morphological acceleration factor: usability, accuracy and run time reductions

Water Qualit

Modelling sediment transport with hysteresis effects

Water Qualit

Using a sand wave model for optimal monitoring of navigation depth

In the Euro Channel to Rotterdam Harbor, sand waves reduce the navigable depth to an unacceptable level. To avoid the risk of grounding, the navigation depth is monitored and sand waves that reduce the navigation depth unacceptably are dredged. After the dredging, the sand waves slowly regain their original height. To reduce the high costs of surveying and dredging, the North Sea Service of the Department of Transport, PublicWorks andWater Management, is implementing a Decision Support System to reduce the required amount of surveys and provide optimal information on the necessity to dredge. Currently, the system predicts the growth of sand waves using a linear trend. The trend is determined from observations using a Kalman-filter including geo-statistical components to incorporate spatial dependencies. This works well for sand waves that are close to their maximum height. After dredging however, the sand wave height is far from its equilibrium and the growth rate is much higher, making the linear prediction worthless. Here we show that replacing the linear trend with a landau equation improves the predictions of the regeneration. Comparison shows that the landau equation predicts the crest evolution better than the linear equation for both undisturbed sand waves and dredged sand waves, with an root mean square error that is 25% less

Probabilistic Channel Infill Approach

Sediment Transpor

On the modelling of biological effects on morphology in estuaries and seas

Morphological modelling aims to explain and predict the changes in rivers, seas and estuaries due to these interaction. In recent history, a lot of progress has been made, especially with stability analysis approaches. However, so far only the physical interactions have been taken into account. It is known however, that biological factors are important to the dynamics of the water systems. In this paper a first step is made in the inclusion of biology into the morphodynamic models. This inclusion is based on the effect that benthic organisms have on the erodibility of the bed. This can easily be included by a change of the critical bed shear stress. These changes in the critical bed shear stress then influence the morphology. This idea has been applied to two cases. The results of the first case indicate that this approach can reproduce the influence of benthic organisms on the mud content of the bed in estuaries. The second case shows that even low numbers of organisms can influence the characteristics of large bed forms