Searched for: author:"Uijttewaal"
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Koopmans, H. (author), Huismans, Y (author), Uijttewaal, W.S.J. (author)
Variable flows and fast morphological changes characterize the river system of Bangladesh, which includes the downstream reaches and delta of the Ganges and Brahmaputra rivers, two of the largest rivers in the world. In contrast, fresh water supply around the country largely depends on much smaller distributaries that take off from those large...
conference paper 2017
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Orru, C. (author), Blom, A. (author), Uijttewaal, W.S.J. (author)

Armor breakup and reformation was studied in a laboratory experiment using a trimodal mixture composed of a 1mm sand fraction and two gravel fractions (6 and 10mm). The initial bed was characterized by a stepwise downstream fining pattern (trimodal reach) and a downstream sand reach, and the experiment was conducted under conditions without...

journal article 2016
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Radermacher, M. (author), De Wit, L. (author), Uijttewaal, W.S.J. (author), Winterwerp, J.C. (author)
When dredging in sensitive environments, efforts have to be made to limit the free dispersal of suspended fine sediment from the dredging spill. Especially the use of hanging silt curtains as an environmental mitigation measure is widespread. Despite frequent application, their ability to reduce turbidity levels through vertical diversion of...
journal article 2015
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Crosato, A. (author), Rajbhandari, N. (author), Comiti, F. (author), Uijttewaal, W.S.J. (author)
Wood transport in rivers, typically occurring during flood events, represents a relevant hazard for its potential to create obstruction at bridges and narrow cross-sections. Therefore, the understanding and prediction of entrainment and transport dynamics of woody material of different shapes, density and dimensions is of great interest for...
conference paper 2011
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Crosato, A. (author), Mosselman, E. (author), Desta, F.B. (author), Uijttewaal, W.S.J. (author)
Alternate bars in straight alluvial channels are migrating or nonmigrating. The currently accepted view is that they are nonmigrating if the width-to-depth ratio is at the value of resonance or if the bars are forced by a persistent local perturbation. We carried out 2-D numerical computations and a long-duration mobile-bed flume experiment to...
journal article 2011
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Van de Sande, S.A.H. (author), Uijttewaal, W.S.J. (author), Verheij, H.J. (author)
Granular filters are used for protection against scour and erosion of base material. For a proper functioning it is necessary that at the interfaces between the filter structure, the subsoil and the water flowing above the filter structure no material will be transported. Different types of granular filters can be distinguished, this paper...
conference paper 2014
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Crosato, A. (author), Getaneh, A.A. (author), Desta, F.B. (author), Uijttewaal, W.S.J. (author), Le, U. (author)
The current view is that migrating bars are the result of morphodynamic instability in straight or mildly-sinuous alluvial channels and are therefore an inevitable feature of alluvial river beds. Steady bars, instead, require some external forcing or specific morphodynamic conditions to develop. Yet, recent numerical tests showed that steady...
conference paper 2010
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Ottevanger, W. (author), Blanckaert, K. (author), Uijttewaal, W.S.J. (author), De Vriend, H.J. (author)
Reduced-order models remain essential tools for meander modeling, especially for processes at large length scales and long time scales, probabilistic simulations, rapid assessments, or when input data are scarce or uncertain. Present reduced-order meander models consider their dependent variables either as small-amplitude variations compared to...
journal article 2013
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Angel, J.A. (author), Gorte, B.G.H. (author), Vargas Luna, A. (author), Uijttewaal, W.S.J. (author)
Experimental work in river morphology has already become a key factor to assess and analyze physical and numerical models that describe bed-level evolution in channels (Paola et al, 2009). Different techniques could be used to measure bed topography in laboratories ranging from traditional to high-technology methods. In this work, the structured...
conference paper 2014
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Crosato, A. (author), Desta, F.B. (author), Cornelisse, J. (author), Uijttewaal, W.S.J. (author)
Migrating alternate bars form in alluvial channels as a result of morphodynamic instability. Extensive literature can be found on their origin and short-term development, but their long-term evolution has been poorly studied so far. In particular, it is not clear whether they eventually reach an equilibrium shape, since short-term experiments...
conference paper 2011
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Crosato, A. (author), Mosselman, E. (author), Desta, F.B. (author), Uijttewaal, W.S.J. (author)
journal article 2011
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Chen, X. (author), Hofland, B. (author), Altomare, C. (author), Uijttewaal, J.S.W. (author)
In this paper the impact process and mechanism of overtopping flow on a vertical wall on a dike crest are investigated by means of a series of physical model tests. A double-peaked force was recognized in a time series of an overtoping flow. Four stages were summarized for the whole overtopping flow impact process. An empirical relationship...
conference paper 2014
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Crosato, A. (author), Desta, F.B. (author), Cornelisse, J. (author), Schuurman, F. (author), Uijttewaal, W.S.J. (author)
Migrating alternate bars form in alluvial channels as a result of morphodynamic instability. Extensive literature can be found on their origin and short-term development, but their long-term evolution has been poorly studied so far. In particular, it is not clear whether migrating bars eventually reach a (dynamic) equilibrium, as in previous...
journal article 2012
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Orru, C. (author), Chavarrias Borras, V. (author), Uijttewaal, W.S.J. (author), Blom, A. (author)
Measurements of spatial and temporal changes in the grain-size distribution of the bed surface and substrate are crucial to improving the modelling of sediment transport and associated grain-size selective processes. We present three complementary techniques to determine such variations in the grain-size distribution of the bed surface in sand...
journal article 2014
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Vargas Luna, A. (author), Crosato, A. (author), Calvani, G. (author), Uijttewaal, W.S.J. (author)
Simulating the morphological adaptation of water systems often requires including the effects of plants on water and sediment dynamics. Physical and numerical models need representing vegetation in a schematic easily-quantifiable way despite the variety of sizes, shapes and flexibility of real plants. Common approaches represent plants as rigid...
journal article 2016
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van Rooijen, E.J. (author), Mosselman, E. (author), Sloff, C.J. (author), Uijttewaal, W.S.J. (author)
Confluences are fascinating elements in river systems. The merging of tributary rivers produces complex hydrodynamics that can play an important role in sediment transport problems, ecological studies or the routing of a pollutant. If the two merging rivers originate from different regions they can have different characteristics. One such a...
conference paper 2017
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Baar, A.W. (author), Weisscher, S.A.H. (author), Uijttewaal, W.S.J. (author), Kleinhans, MG (author)

We experimentally tested the effect of a  large range in helical flow intensity and  sediment mobility on equilibrium transverse  slopes, which resulted in a function for slope  effects depending on bed state and  sediment transport mode, that deviates from  linear functions with sediment mobility in  literature....

conference paper 2017
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Duro, G. (author), Uijttewaal, W.S.J. (author), Kleinhans, M (author), Crosato, A. (author)

Waterways serve for several functions besides  transporting goods and people. The ecological  importance of navigable rivers has taken much  attention during recent decades bringing efforts  to improve these natural corridors for fauna and  flora (Boeters et al., 1997).  Following the policy of the European Water...

conference paper 2017
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Jammers, S.M.M. (author), Paarlberg, AJ (author), Mosselman, E. (author), Uijttewaal, W.S.J. (author)

Longitudinal training dams (LTDs) are  constructed in the River Waal in the  Netherlands. They are aligned parallel to the  river shore and divide the river into a main and  side channel. The existing groynes are  removed yielding more discharge capacity at  high flows. The side channel creates possibly a ...

conference paper 2017
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Weisscher, S.A.H. (author), Baar, A.W. (author), Uijttewaal, W.S.J. (author), Kleinhans, MG (author)

Lateral sorting (= bend sorting) is observed in  natural meanders, where the inner and outer  bend are fairly fine and coarse, respectively  (e.g. Julien and Anthony, 2002; Clayton and  Pitlick, 2007). This is caused by the mass  differences between grains on a transverse  slope, leading to coarser grains being...

conference paper 2017
Searched for: author:"Uijttewaal"
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