METHOD TO EVALUATE LONGITUDINAL SEDIMENT SORTING FOCUSING ON SEDIMENT TRANSPORT MECHANISM

2018 ◽  
Vol 74 (5) ◽  
pp. I_907-I_912
Author(s):  
Daisuke HARADA ◽  
Shinji EGASHIRA
Keyword(s):  
Sediment Transport ◽  
Transport Mechanism ◽  
Sediment Sorting

scholarly journals The Properties of Sediment Transport Mechanism in River Mouth of Rupat Strait

2020 ◽  
Author(s):  
Mubarak Mubarak ◽  
Rifardi Rifardi ◽  
Ahmad Nurhuda ◽  
Albert Sulaiman
Keyword(s):  
Sediment Transport ◽  
Transport Mechanism ◽  
High Tide ◽  
River Mouth ◽  
Ocean Current ◽  
Anthropogenic Factors ◽  
Explicit Method ◽  
Transport Modelling ◽  
Sediment Transport Modelling ◽  
Malacca Strait

The Rupat Strait, a part of the Malacca Strait, is recognized as semi-closed waters and shows a high activity; thus, discovering the transport sediment mechanism of the strait as a consequence of ambient and anthropogenic forces is essential. Hydrodynamic and sediment transport modelling was constructed using the 2-Dimensional Explicit method which is averaged over depth. The results show that the dispersion of sediment at high tide is longer than that at low tide. This follows the hydrodynamic model in which current velocity at high tide is greater than the ocean current at the low tide. The previous sediment observation supports the results of transport sediment modelling, indicating that the anthropogenic factors are highly associated with the sedimentation in the Rupat strait

scholarly journals TRANSPORT OF NILE SAND ALONG THE SOUTHEASTERN MEDITERRANEAN COAST

1984 ◽  
Vol 1 (19) ◽  
pp. 87
Author(s):  
Zev Carmel ◽  
Douglas L. Inman ◽  
Abraham Golik
Keyword(s):  
Sediment Transport ◽  
Transport Mechanism ◽  
Nile Delta ◽  
Mediterranean Coast ◽  
Longshore Sediment Transport ◽  
Transport Path ◽  
Directional Wave ◽  
Wave Induced ◽  
Annual Transport ◽  
Good Agreement

The potential for longshore sediment transport (LST) is estimated from a three-year set of directional wave data measured off Haifa, Israel. The resulting annual cycle of LST, together with an analysis of the wave and shore characteristics, suggests a wave-induced sediment transport mechanism with a uni-directional annual transport that gradually decreases along the transport path from the source (Nile delta) to sink (Haifa Bay). Existing estimates of the rates of transport of Nile sediment are in good agreement with this result.

scholarly journals Opposite hysteresis of sand and gravel transport upstream and downstream of a bifurcation during a flood in the River Rhine, the Netherlands

2007 ◽  
Vol 86 (3) ◽  
pp. 273-285 ◽  
Author(s):  
M.G. Kleinhans ◽  
A.W.E. Wilbers ◽  
W.B.M. ten Brinke
Keyword(s):  
Sediment Transport ◽  
Transport Rate ◽  
River Rhine ◽  
Rhine River ◽  
Bed Sediment ◽  
Hydraulic Roughness ◽  
Meandering River ◽  
Sediment Sorting ◽  
Sand And Gravel ◽  
Clockwise Hysteresis

AbstractAt river bifurcations water and sediment is divided among the downstream branches. Prediction of the sediment transport rate and division thereof at bifurcations is of utmost importance for understanding the evolution of the bifurcates for short-term management purposes and for long-term fluvial plain development. However, measured sediment transports in rivers rarely show a uniquely determined relation with hydrodynamic parameters. Commonly a hysteresis is observed of transport rate as a function of discharge or shear stress which cannot be explained with the standard sediment transport predictor approach. The aim of this paper is to investigate the causes of hysteresis at a bifurcation of the lower Rhine river, a meandering river with stable banks, large dunes during flood, and poorly sorted bed sediment. The hydrodynamics and bed sediment transport were measured in detail during a discharge wave with a recurrence interval larger than 10 years. Surprisingly, the hysteresis in bedload against discharge was in the opposite direction upstream and downstream of the bifurcation. The upstream clockwise hysteresis is caused by the lagging development of dunes during the flood. The counter-clockwise hysteresis downstream of the bifurcation is caused by a combination of processes in addition to dune lagging, namely 1) formation of a scour zone upstream of the bifurcation, causing a migrating fine sediment wave, and 2) vertical bed sorting of the bed sediment by dunes with avalanching lee-sides, together leading to surface-sediment fining and increased transport during and after the flood. These findings lead to challenges for future morphological models, particularly for bifurcations, which will have to deal with varying discharge, sediment sorting in the channel bed, lagging dunes and related hydraulic roughness.

Response of soil erosion and sediment sorting to the transport mechanism on a steep rocky slope

2019 ◽  
Vol 44 (12) ◽  
pp. 2467-2478 ◽  
Author(s):  
Zhen Han ◽  
Xiaoyan Wang ◽  
Dandan Song ◽  
Xinxin Li ◽  
Ping Huang ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Transport Mechanism ◽  
Rocky Slope ◽  
Sediment Sorting

Numerical simulation of sediment transport in a U-shaped channel with lateral intake: Effects of intake position and diversion angle

2019 ◽  
Vol 30 (09) ◽  
pp. 1950071 ◽  
Author(s):  
Keivan Tavakoli ◽  
Hossien Montaseri ◽  
Pourya Omidvar ◽  
Stefania Evangelista
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Transport Mechanism ◽  
Discrete Phase Model ◽  
Reference Time ◽  
Bed Topography ◽  
Discharge Ratio ◽  
Discrete Phase ◽  
Sediment Particles ◽  
Good Agreement

In this work, the mechanism of sediment transport in a U-shaped channel with a lateral intake is investigated experimentally and numerically, together with the processes of sediment entry into the intake itself and formation of bed topography. Dry sediment is injected into a steady flow in a rigid channel with a bend and sediment particles are traced in time. In order to validate the numerical model, the three components of the flow velocity, as well as the sediment path in time and the diverted sediment ratios, are measured experimentally. A numerical Discrete Phase Model (DPM) is then applied to study the effect of the intake position and diversion angle on the sediment transport mechanism in the bend. The DPM has, in fact, the capability of specifying for each particle its position relative to a reference time and space and, thereby, it is used in this study to analyze the phenomenon evolution and determine the sediment particles diverted into the intake. The comparison between the experimental data and the DPM numerical results shows a good agreement. In order to investigate the mechanism of sediment transport and to evaluate the percentage of the diverted sediments, a parametric study is then conducted through the numerical model, with different positions of the outer bend of the channel, diversion angles of the lateral intake and diversion discharge ratios. The results show that the mechanism of sediment entry into the lateral intake is affected by the diversion discharge ratio. For low discharge ratios, the mechanism of sediment entry to the lateral intake only consists of continuous entrance from the upstream edge of the intake. With the increase of the discharge ratio, it consists of a continuous entrance from the downstream edge and a periodic entrance from the upstream edge of the intake. The DPM results show that, for all diversion discharge ratios, the minimum percentage of sediment entered into the lateral intake corresponds to the position of 120∘ and diversion angle equal to 50∘.

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