scholarly journals Author Correction: The Incipient Motion Features of Sediment from Yangtze Estuary: Annular Flume Experiments

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Huang Wei ◽  
Liu Ya-kun ◽  
Wu Hua-lin ◽  
Wan Yuan-yang
2018 ◽  
Vol 54 (1) ◽  
pp. 19-45 ◽  
Author(s):  
Anne W. Baar ◽  
Jaco de Smit ◽  
Wim S. J. Uijttewaal ◽  
Maarten G. Kleinhans

2017 ◽  
Vol 32 (3) ◽  
pp. 421-431
Author(s):  
Olya Skulovich ◽  
Catrina Cofalla ◽  
Caroline Ganal ◽  
Holger Schüttrumpf ◽  
Avi Ostfeld

2013 ◽  
Vol 405-408 ◽  
pp. 1476-1480
Author(s):  
Jie Gu ◽  
Xiao Li Wang ◽  
Xin Qin ◽  
Dan Qing Ma ◽  
Ji Zhong Yang ◽  
...  

Sandbar is the main geomorphic unit in estuary, and due to the effects of runoff, tide and fresh-salt water mixing, the sediment movement there differs from others. Taking the Yangtze Estuary as an example, firstly, its sediment transport forms many circles both in longitudinal sections and transverse sections. Secondly, its sediment trapping is controlled by two different mechanisms, tidal current and salt water. The former contains the delay effect of sediment deposition and incipient motion, the asymmetry of flood and ebb, and the separation of flood and ebb, whereas the latter includes the influence of the saltwater wedge density current, the aggregation of the saltwater intrusion fronts, and the trapping of flocculation. Finally, its sediment re-suspension occurs three or four times ,not noly at the moment of flood or ebb maximumbut also at the transferring period from flood to ebb or from ebb to flood.


2003 ◽  
Vol 34 (1-2) ◽  
pp. 125-138 ◽  
Author(s):  
David Milburn ◽  
B.G. Krishnappan

A large volume sample of river-bed cohesive sediment and water from Hay River, Northwest Territories, Canada was collected during a spring field program in 2000 as part of a study on under-ice movement of sediment just before breakup. Controlled laboratory experiments were subsequently conducted on the Hay River water/sediments in a rotating annular flume at Burlington, Ontario, Canada to better understand the deposition and erosion processes of cohesive sediment transport. The deposition experiments in the rotating flume confirmed that the Hay River sediment is cohesive and the critical shear stress for deposition and the rates of deposition are a function of bed shear stress and the initial concentration of the sediment in suspension. The erosion experiments provided quantitative data on the critical shear stress for erosion and the rates of erosion as a function of bed shear stress and the age of the sediment deposit. The erosion experiments also indicated that the growth of the biofilm had an influence on the erosion characteristics of the Hay River sediment. Based on the data from the rotating circular flume experiments, a modelling strategy is proposed for calculating the under-ice transport of the cohesive sediments in the Hay River.


2018 ◽  
Vol 1 (2) ◽  
pp. 99-111
Author(s):  
Olya Skulovich ◽  
Caroline Ganal ◽  
Leonie K. Nüßer ◽  
Catrina Cofalla ◽  
Holger Schuettrumpf ◽  
...  

Abstract Artificial neural network is used to predict development of suspended sediment concentration in annular flume experiments on cohesive sediment erosion. Natural sediment for the experiments was taken from the River Rhine and subjected to a consecutive increase in the bed shear stress. The development of the suspended particulate matter (SPM) was measured and then utilized for artificial neural network training, validation, and testing, including independent testing on new data sets. Several network configurations were examined, in particular, with and without autoregressive input. Additionally, relative importance of auxiliary physical-chemical parameters was analyzed. Artificial neural network with autoregressive input showed very high precision in the SPM prediction for all independent test cases achieving average mean squared error 0.034 and regression value 0.998. It was found that for an abundant training sample, the SPM parameter itself is enough to obtain high quality prediction. At the same time, physical-chemical parameters may provide some improvement to the artificial neural network prediction in cases that comprise values unprecedented in the training sample.


2020 ◽  
pp. 34-42
Author(s):  
Thibault Chastel ◽  
Kevin Botten ◽  
Nathalie Durand ◽  
Nicole Goutal

Seagrass meadows are essential for protection of coastal erosion by damping wave and stabilizing the seabed. Seagrass are considered as a source of water resistance which modifies strongly the wave dynamics. As a part of EDF R & D seagrass restoration project in the Berre lagoon, we quantify the wave attenuation due to artificial vegetation distributed in a flume. Experiments have been conducted at Saint-Venant Hydraulics Laboratory wave flume (Chatou, France). We measure the wave damping with 13 resistive waves gauges along a distance L = 22.5 m for the “low” density and L = 12.15 m for the “high” density of vegetation mimics. A JONSWAP spectrum is used for the generation of irregular waves with significant wave height Hs ranging from 0.10 to 0.23 m and peak period Tp ranging from 1 to 3 s. Artificial vegetation is a model of Posidonia oceanica seagrass species represented by slightly flexible polypropylene shoots with 8 artificial leaves of 0.28 and 0.16 m height. Different hydrodynamics conditions (Hs, Tp, water depth hw) and geometrical parameters (submergence ratio α, shoot density N) have been tested to see their influence on wave attenuation. For a high submergence ratio (typically 0.7), the wave attenuation can reach 67% of the incident wave height whereas for a low submergence ratio (< 0.2) the wave attenuation is negligible. From each experiment, a bulk drag coefficient has been extracted following the energy dissipation model for irregular non-breaking waves developed by Mendez and Losada (2004). This model, based on the assumption that the energy loss over the species meadow is essentially due to the drag force, takes into account both wave and vegetation parameter. Finally, we found an empirical relationship for Cd depending on 2 dimensionless parameters: the Reynolds and Keulegan-Carpenter numbers. These relationships are compared with other similar studies.


2009 ◽  
Vol 36 (1) ◽  
pp. 80-95
Author(s):  
Achanta Ramakrishna Rao ◽  
Bimlesh Kumar
Keyword(s):  

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