Modeling hydraulic resistance of floodplain vegetation

In this thesis, methods are investigated that describe the impact of vegetation on a flow field, and their potential for application in river-reach hydraulic computational models. This field of research is of great importance to river flood studies, as vegetation-covered foodplains commonly become part of the river flow section during high-discharge conditions. In this respect, the obstruction\ud of vegetation to flow needs to be taken into account if trying to predict overall flow behavior. To describe the impact of vegetation on a river-reach scale, ob-\ud structing vegetation should be incorporated in terms of easily measurable input parameters and require only minimal additional computational effort. In the current work, such a method is proposed

Hydraulic Resistance of Vegetation in River Flow Applications

Proceedings of the Seventh International Conference on Hydroscience and Engineering, Philadelphia, PA, September 2006. http://hdl.handle.net/1860/732If vegetated regions become part of a river’s flow field, the hydraulic resistance of vegetation affects the overall conveyance. Several descriptions exist to describe this type of flow; among them are empirical relations and relations that are process-based. In the current work three expressions are considered that have equal input parameters, similar levels of complexity but different theoretical backgrounds. The performance of the three methods is evaluated by comparison with flow measurements (collected from literature), and limits are given for their practical use

Effect of vegetation growth in drainage canals on water management

In 2002 a new regulation was adopted in the Netherlands to protect flora and fauna. As a consequence mowing of drainage canals will be restricted during the growing season leading to vegetated canals that may hamper the discharge of water. In the summer of 2006 a field experiment has been executed in combination with a model study to investigate the effects of vegetation growth in the Fliert, a drainage canal located in the central part of the Netherlands. The field experiments showed extensive vegetation growth in absence of mowing. For the model study SOBEK Rural was used to evaluate different rainfall and vegetation (mowing) scenarios. From the model study it could be concluded that vegetation growth in combination with high rainfall can lead to water management problems. This means that if mowing is not allowed alternative measures are necessary. Unfortunately, model results could not be validated due to a relative dry summer

On the importance of discharge variability in the morphodynamic modeling of rivers

River morphodynamics and sediment transportRiver morphology and morphodynamic