A revised model for water flow, sediment transport, bed topography and grain size sorting in natural river bends

The paper presents recommendations for using the results obtained in sediment transport simulation and modeling of channel deformations in rivers. This work relates to the issues of empirical modeling of the water flow characteristics in natural riverbeds with a movable bottom (alluvial channels) which are extremely complex. The study shows that in the simulation of sediment transport and calculation of channel deformations in the rivers, it is expedient to use the calculation dependences of Chézy’s coefficient for assessing the roughness of the bottom sediment mixture, or the dependences of the form based on the field investigation data. Three models are most commonly used and based on the original formulas of Meyer-Peter and Müller (1948), Einstein (1950) and van Rijn (1984). This work deals with assessing the hydraulic resistance of the channel and improving the river sediment transport model in a simulation of riverbed transformation on the basis of previous research to verify it based on 296 field measurements on the Central-East European lowland rivers. The performed test calculations show that the modified van Rijn formula gives the best results from all the considered variants.

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A model for predicting the lateral distribution of sediment transport in river bends

ISH Journal of Hydraulic Engineering ◽

10.1080/09715010.2021.1954100 ◽

2021 ◽

pp. 1-10

Author(s):

Abdolreza Zahiri ◽

Xiaonan Tang ◽

Behrooz Dahanzadeh

Keyword(s):

Sediment Transport ◽

Lateral Distribution ◽

River Bends

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Lower-stage plane bed topography is an outcome of rarefied, intermittent sediment transport

10.1002/essoar.10503463.4 ◽

2021 ◽

Author(s):

Thomas Christopher Ashley ◽

Suleyman Naqshband ◽

Brandon McElroy

Keyword(s):

Sediment Transport ◽

Bed Topography ◽

Lower Stage

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Flow Characteristics and Grain Size Distribution of Granular Gangue Mineral by Compaction Treatment

Advances in Materials Science and Engineering ◽

10.1155/2017/2509286 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Ran Yuan ◽

Dan Ma ◽

Hongwei Zhang

Keyword(s):

Weight Loss ◽

Grain Size ◽

Size Distribution ◽

Grain Size Distribution ◽

Water Flow ◽

Fine Particles ◽

Flow Characteristics ◽

Test System ◽

Chemical Components ◽

Gangue Mineral

A test system for water flow in granular gangue mineral was designed to study the flow characteristics by compaction treatment. With the increase of the compaction displacement, the porosity decreases and void in granular gangue becomes less. The main reason causing initial porosity decrease is that the void of larger size is filled with small particles. Permeability tends to decrease and non-Darcy flow factor increases under the compaction treatment. The change trend of flow characteristics shows twists and turns, which indicate that flow characteristics of granular gangue mineral are related to compaction level, grain size distribution, crushing, and fracture structure. During compaction, larger particles are crushed, which in turn causes the weight of smaller particles to increase, and water flow induces fine particles to migrate (weight loss); meanwhile, a sample with more weight of size (0–2.5 mm) has a higher amount of weight loss. Water seepage will cause the decrease of some chemical components, where SiO2 decreased the highest in these components; the components decreased are more likely locked at fragments rather than the defect of the minerals. The variation of the chemical components has an opposite trend when compared with permeability.

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Sediment transport patterns on the Estremadura Spur continental shelf: Insights from grain-size trend analysis

Journal of Sea Research ◽

10.1016/j.seares.2014.04.001 ◽

2014 ◽

Vol 93 ◽

pp. 28-32 ◽

Cited By ~ 5

Author(s):

Maria Balsinha ◽

Carlos Fernandes ◽

Anabela Oliveira ◽

Aurora Rodrigues ◽

Rui Taborda

Keyword(s):

Grain Size ◽

Sediment Transport ◽

Continental Shelf ◽

Trend Analysis ◽

Transport Patterns ◽

Grain Size Trend Analysis

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Sediment transport processes across the Tibetan Plateau inferred from robust grain-size end members in lake sediments

Climate of the Past ◽

10.5194/cp-10-91-2014 ◽

2014 ◽

Vol 10 (1) ◽

pp. 91-106 ◽

Cited By ~ 61

Author(s):

E. Dietze ◽

F. Maussion ◽

M. Ahlborn ◽

B. Diekmann ◽

K. Hartmann ◽

...

Keyword(s):

Grain Size ◽

Sediment Transport ◽

Tibetan Plateau ◽

Transport Processes ◽

The Tibetan Plateau ◽

Dust Deposition ◽

Northerly Wind ◽

Near Surface ◽

Depositional Processes ◽

End Members

Abstract. Grain-size distributions offer powerful proxies of past environmental conditions that are related to sediment sorting processes. However, they are often of multimodal character because sediments can get mixed during deposition. To facilitate the use of grain size as palaeoenvironmental proxy, this study aims to distinguish the main detrital processes that contribute to lacustrine sedimentation across the Tibetan Plateau using grain-size end-member modelling analysis. Between three and five robust grain-size end-member subpopulations were distinguished at different sites from similarly–likely end-member model runs. Their main modes were grouped and linked to common sediment transport and depositional processes that can be associated with contemporary Tibetan climate (precipitation patterns and lake ice phenology, gridded wind and shear stress data from the High Asia Reanalysis) and local catchment configurations. The coarse sands and clays with grain-size modes >250 μm and <2 μm were probably transported by fluvial processes. Aeolian sands (~200 μm) and coarse local dust (~60 μm), transported by saltation and in near-surface suspension clouds, are probably related to occasional westerly storms in winter and spring. Coarse regional dust with modes ~25 μm may derive from near-by sources that keep in longer term suspension. The continuous background dust is differentiated into two robust end members (modes: 5–10 and 2–5 μm) that may represent different sources, wind directions and/or sediment trapping dynamics from long-range, upper-level westerly and episodic northerly wind transport. According to this study grain-size end members of only fluvial origin contribute small amounts to mean Tibetan lake sedimentation (19± 5%), whereas local to regional aeolian transport and background dust deposition dominate the clastic sedimentation in Tibetan lakes (contributions: 42 ± 14% and 51 ± 11%). However, fluvial and alluvial reworking of aeolian material from nearby slopes during summer seems to limit end-member interpretation and should be crosschecked with other proxy information. If not considered as a stand-alone proxy, a high transferability to other regions and sediment archives allows helpful reconstructions of past sedimentation history.

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