Monitoring sediment transport patterns on an energetic ebb-tidal delta using dual-signature tracers

2018 ◽  
Author(s):  
Stuart Pearson ◽  
Bram van Prooijen ◽  
Jack Poleykett ◽  
Matthew Wright ◽  
Kevin Black ◽  
...  
2020 ◽  
Vol 8 (11) ◽  
pp. 892
Author(s):  
Laura Brakenhoff ◽  
Reinier Schrijvershof ◽  
Jebbe van der Werf ◽  
Bart Grasmeijer ◽  
Gerben Ruessink ◽  
...  

Bedform-related roughness affects both water movement and sediment transport, so it is important that it is represented correctly in numerical morphodynamic models. The main objective of the present study is to quantify for the first time the importance of ripple- and megaripple-related roughness for modelled hydrodynamics and sediment transport on the wave- and tide-dominated Ameland ebb-tidal delta in the north of the Netherlands. To do so, a sensitivity analysis was performed, in which several types of bedform-related roughness predictors were evaluated using a Delft3D model. Also, modelled ripple roughness was compared to data of ripple heights observed in a six-week field campaign on the Ameland ebb-tidal delta. The present study improves our understanding of how choices in model set-up influence model results. By comparing the results of the model scenarios, it was found that the ripple and megaripple-related roughness affect the depth-averaged current velocity, mainly over the shallow areas of the delta. The small-scale ripples are also important for the suspended load sediment transport, both indirectly through the affected flow and directly. While the current magnitude changes by 10–20% through changes in bedform roughness, the sediment transport magnitude changes by more than 100%.


1988 ◽  
Vol 23 (2) ◽  
pp. 243-252 ◽  
Author(s):  
J.E. Bruton ◽  
J.H. Jerome ◽  
R.P. Bukata

Abstract Satellite data from Landsats 4 and 5 were utilized to delineate the seasonal variations of sediment transport zones in the Lac Saint-Pierre region of the St. Lawrence River corridor. A seasonally cyclic succession of patterns displaying persistent, mutually independent, and extensive (in both space and time) turbidity zones was clearly in evidence. Visible and thermal data in both imagery and digital formats were used to show the close relationships existing among the distinct zonal synoptic patterns, the bathymetry of lake and river, and the near surface aquatic temperatures.


2014 ◽  
Vol 93 ◽  
pp. 28-32 ◽  
Author(s):  
Maria Balsinha ◽  
Carlos Fernandes ◽  
Anabela Oliveira ◽  
Aurora Rodrigues ◽  
Rui Taborda

2018 ◽  
Vol 85 ◽  
pp. 216-220 ◽  
Author(s):  
Jianfeng Tao ◽  
Fan Xu ◽  
Peng Yao ◽  
Zeng Zhou ◽  
Changkuan Zhang

2021 ◽  
Author(s):  
Yu Wang ◽  
Bao-long Li ◽  
Juan-juan Liu ◽  
Qi Feng ◽  
Wei Liu ◽  
...  

Abstract Spatial variations in grain-size parameters can reflect river sediment transport patterns and depositional dynamics. Therefore, 22 surficial sediment samples taken from the Heihe River and its cascade reservoirs were analyzed to better understand the impact of cascade reservoir construction on sediment transport patterns in inland rivers in China. The results showed that the longitudinal distribution of sediment grain size in the Heihe River was significantly affected by the influence of the cascade reservoirs. The grain size of the reservoir sediments within the cascade reservoir system was much lower than that of sediments in the natural river section, and the sediments in the natural river were well sorted, exhibiting leptokurtosis and positive or very positive skew. The lower reaches of the dammed river experienced strong erosion, and the grains of the bed sediments were coarse and poorly sorted; the grain-size distributions were more positively skewed and exhibited leptokurtosis. The backwater zone of the reservoir was influenced by both backwater and released water, and the sediment grain size was between the grain size of the natural river and that of the lower reaches of the dam; these sediments were moderately well sorted and had a positively skewed, leptokurtic grain-size distribution. Sedimentary environmental analysis revealed that the characteristics of the sediment grain size in an upstream tributary of the Heihe River were more influenced by source material than by hydrodynamic conditions, while the grain-size characteristics of the mainstream sediments were controlled mainly by hydrodynamic conditions.


2019 ◽  
Vol 32 (5) ◽  
pp. 1184-1212
Author(s):  
Martin Muravchik ◽  
Gijs A. Henstra ◽  
Gauti T. Eliassen ◽  
Rob L. Gawthorpe ◽  
Mike Leeder ◽  
...  

Author(s):  
James F. Bramante ◽  
Andrew D. Ashton ◽  
Curt D. Storlazzi ◽  
Olivia M. Cheriton ◽  
Jeffrey P. Donnelly

2002 ◽  
Vol 26 (1) ◽  
pp. 47-75 ◽  
Author(s):  
Ian J. Walker ◽  
William G. Nickling

Recent research literature on secondary airflow and sediment transport patterns over flow-transverse dunes is reviewed. Various issues surrounding the behaviour, modelling and sedimentological implications of near-surface airflow dynamics over dunes are discussed, including: the Law of the Wall; the Jackson and Hunt airflow model; the effects of streamline compression, acceleration and curvature on stoss slope shear stress; and, in particular, recent efforts to characterize secondary lee-side airflow patterns. A revised conceptual model of lee-side airflow is presented and areas for further research are identified regarding the implications of such patterns for dune sedimentary dynamics, morphology, and migration.


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