Searched for: author:"Uijttewaal"
(21 - 40 of 64)

Pages

document
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
document
van Linge, B.W. (author), Mosselman, E. (author), van Vuren, S. (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
document
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
document
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
document
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
document
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
document
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
document
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
document
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
document
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
document
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
document
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
document
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
document
Uijttewaal, W.S.J. (author)
journal article 2014
document
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
document
Orru, C. (author), Eleftherakis, D. (author), Blom, A. (author), Snellen, M. (author), Uijttewaal, W.S.J. (author), Simons, D.G. (author)
Grain size changes in a river dominated by mixed sediment are the outcome of sedimentary grain sizeselective processes. Progress in the measurement techniques that define the spatial and temporal variation in grain size is necessary to provide new insights in this field. Techniques as image analysis and acoustic methods have emerged in the last...
conference paper 2013
document
Vargas Luna, A. (author), Uijttewaal, W.S.J. (author), Crosato, A. (author), Tanczos, I.C. (author), De Vries, M. (author)
conference paper 2013
document
Ali, S. (author), Uijttewaal, W.S.J. (author)
At high water stages obstacles 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 oblique weir-like obstacles. The experiments have...
journal article 2013
document
Orru, C. (author), Blom, A. (author), Uijttewaal, W.S.J. (author)
journal article 2012
document
Vargas Luna, A. (author), Crosato, A. (author), Uijttewaal, W.S.J. (author)
conference paper 2012
Searched for: author:"Uijttewaal"
(21 - 40 of 64)

Pages