Searched for: author:"Uijttewaal, W.S.J."
(21 - 40 of 67)

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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  largerange in helical flow intensity and  sedimentmobility on equilibrium transverse  slopes,which resulted in a function for slope  effectsdepending on bed state and  sedimenttransport mode, that deviates from  linearfunctions with sediment mobility in  literature...
abstract 2017
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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...
abstract 2017
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Bonilla Porras, J.A. (author), Crosato, A. (author), Uijttewaal, W.S.J. (author)
Although many studies regarding bank erosion  and accretion can be found in the literature, it is  not common to find works studying the interaction  between opposite banks. Some existing  morphodynamic models describe bank erosion as  an event that depends on near-bank flow and bed  topography, as well as on...
abstract 2017
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Le, T.B. (author), Crosato, A. (author), Uijttewaal, W.S.J. (author)
Recently, engineers propose longitudinal  training walls to replace traditional transverse  groynes. This new intervention is expected to  maintain a navigation route under low flow  conditions while not hampering flow  conveyance of the river channel. Navigation  occurs mainly in low-land river channels where ...
abstract 2017
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Maljaars, J.M. (author), Labeur, R.J. (author), Möller, M. (author), Uijttewaal, W.S.J. (author)
In this work the feasibility of a numerical wave tank using a hybrid particle-mesh method is investigated. Based on the Fluid Implicit Particle Method (FLIP) a generic formulation for the hybrid method is presented for incompressible multi-phase flows involving large density jumps and wave generating boundaries. The performance of the method...
journal article 2017
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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...
abstract 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...
abstract 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...
abstract 2017
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van Linge, B.W. (author), Mosselman, E. (author), van Vuren, Saskia (author), Rongen, G.W.F. (author), Uijttewaal, W.S.J. (author)
With the intention to reduce the negative  effects of ongoing bed erosion, as well as to  improve several other river functions such as  protection against floods, provision of safe and  efficient navigation and ecology, a ‘pilot project  longitudinal training dams’ was initiated. The  training dams have recently...
conference paper 2017
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Tas, S.A.J. (author), Gijón Mancheño, A. (author), Herman, P.M.J. (author), Reniers, A.J.H.M. (author), Uijttewaal, W.S.J. (author), Winterwerp, J.C. (author)
In this paper the typical hydrodynamics on mangrove-mud coasts are studied. Worldwide, these coasts experience serious erosion problems, and while the importance of mangrove ecosystems is becoming widely recognised, mangrove restoration projects frequently fail due to poor understanding of the system, especially the hydrodynamics. Therefore, a...
abstract 2017
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Gijón Mancheño, A. (author), Tas, S.A.J. (author), Herman, P.M.J. (author), Reniers, A.J.H.M. (author), Uijttewaal, W.S.J. (author), Winterwerp, J.C. (author)
During recent decades, mangrove forests have experienced severe degradation due to unsustainable land use. Restoration of mangrove ecosystems requires the recovery of their habitat, considering ecology, hydrology, hydrodynamics, and sediment transport. In a first pilot in 2013, brushwood dams were built on the eroding coast of Demak, Indonesia,...
abstract 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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Steenstra, Remco (author), Hofland, B. (author), Paarlberg, Andries (author), Smale, Alfons (author), Huthoff, Fredrik (author), Uijttewaal, W.S.J. (author)
A stability parameter for rock in bed protections under nonuniform stationary flow is derived. The influence of the mean flow velocity, turbulence, and mean acceleration of the flow are included explicitly in the parameter. The relatively new notion of explicitly incorporating the mean acceleration of the flow significantly improves the...
journal article 2016
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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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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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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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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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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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Ali, S. (author), Uijttewaal, W.S.J. (author)
At high water stages, obstacles (submerged and particularly emerged vegetation) in the flood plains of a river contribute to the flow resistance and hamper the conveyance capacity. In particular the elevated vegetated parts are expected to play an important role. The objective of this research work is to determine the form drag due to vegetated...
journal article 2014
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Uijttewaal, W.S.J. (author)
journal article 2014
Searched for: author:"Uijttewaal, W.S.J."
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