scholarly journals Fine sediment deposits in gravel bed rivers: Sensitivity analysis to particle properties using a 2D hydrodynamic and sediment model

2020 ◽  
pp. 1163-1171
Author(s):  
H. Haddad ◽  
M. Jodeau ◽  
G. Antoine ◽  
N. Claude ◽  
C. Legout
Keyword(s):  
Sensitivity Analysis ◽  
Fine Sediment ◽  
Particle Properties ◽  
Gravel Bed ◽  
Sediment Deposits ◽  
Gravel Bed Rivers ◽  
Sediment Model

Erodibility of fine sediment deposits in gravel bed rivers: investigation of the spatial variability

2021 ◽  
Author(s):  
Hanna Haddad ◽  
Magali Jodeau ◽  
Germain Antoine ◽  
Cédric Legoût
Keyword(s):  
Spatial Variability ◽  
Spatial Organization ◽  
Fine Sediment ◽  
Aquatic Life ◽  
Vegetation Growth ◽  
Gravel Bed ◽  
Fine Sediments ◽  
Sediment Deposits ◽  
Low Altitude ◽  
Gravel Bed Rivers

<p>Fine sediments exhibit various stages of deposition and erosion during their transport from hillslopes to the ocean. In mountainous environments, high fine sediment load during runoff or dam flushing events can lead to important amounts of deposits in gravel bed rivers. Massive deposits may lead to bar elevation, riparian vegetation growth and consequently to bar stabilization, which can increase flood risks. High amount of fine sediment deposits alters also aquatic life and habitat.</p><p>In order to better understand the dynamics of re-suspension of these deposits, and to accurately predict it with numerical modelling, field monitoring campaigns were performed to assess both the spatial variability and the controlling factors of the erodibility of fine deposits. The cohesive strength-meter (CSM) device, a pocket penetrometer and a pocket shear vane were used to evaluate the erodibility of fine sediments deposited in two rivers in the French Alps: The Isère and Galabre.</p><p>The results highlight the specificity of gravel bed rivers with an abundance of areas of deposition of fine sediments, which are discontinuous compared to estuaries and lowland rivers. A high spatial variability of the erodibility was observed and related to the spatial organization of the deposits. The location of the deposit and its elevation, the moisture and the grain sizes are inter-related and have important correlations with the erodibility. Measurements show that high altitude dry deposits and low altitude humid deposits are more easily eroded than intermediate deposits with medium moisture. The measured variables explain part of the variability of the erodibility but other processes such as the history or the origin of the deposit might also be important factors to consider.</p>

scholarly journals The Prediction of Fine Sediment Distribution in Gravel-Bed Rivers Using a Combination of DEM and FNN

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1515
Author(s):  
Van Hieu Bui ◽  
Minh Duc Bui ◽  
Peter Rutschmann
Keyword(s):  
Feedforward Neural Networks ◽  
Fine Sediment ◽  
Sediment Distribution ◽  
Gravel Bed ◽  
Fine Sediments ◽  
Porosity Variation ◽  
Sediment Sorting ◽  
Gravel Bed Rivers ◽  
Bed Material ◽  
The Relationship

Large amounts of fine sediment infiltration into void spaces of coarse bed material have the ability to alter the morphodynamics of rivers and their aquatic ecosystems. Modelling the mechanisms of fine sediment infiltration in gravel-bed is therefore of high significance. We proposed a framework for calculating the sediment exchange in two layers. On the basis of the conventional approaches, we derived a two-layer fine sediment sorting, which considers the transportation of fine sediment in the form of infiltration into the void spaces of the gravel-bed. The relationship between the fine sediment exchange and the affected factors was obtained by using the discrete element method (DEM) in combination with feedforward neural networks (FNN). The DEM model was validated and applied for gravel-bed flumes with different sizes of fine sediments. Further, we developed algorithms for extracting information in terms of gravel-bed packing, grain size distribution, and porosity variation. On the basis of the DEM results with this extracted information, we developed an FNN model for fine sediment sorting. Analyzing the calculated results and comparing them with the available measurements showed that our framework can successfully simulate the exchange of fine sediment in gravel-bed rivers.

scholarly journals Infiltration Depth of Mineral Particles in Gravel-Bed Rivers

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1285
Author(s):  
Natalia Bustamante-Penagos ◽  
Yarko Niño
Keyword(s):  
Relative Density ◽  
Fine Particles ◽  
Reynolds Numbers ◽  
Fine Sediment ◽  
Infiltration Depth ◽  
Gravel Bed ◽  
Mineral Particles ◽  
Gravel Bed Rivers ◽  
Relationship Of ◽  
The Relationship

This article discusses the results of an experimental study of a spill of mineral particles in gravel-bed rivers due to mining accidents. The purpose of this research is to characterize the dynamics of the fine mining particles spilled on a bed of immobilized gravel as a hyper-concentrated mixture and to experimentally characterize the infiltration phenomenon. We analyzed the type of infiltration considering the dimensionless coarse to fine particle size relationship, the dimensionless weight of the fine particles, the relative density of the particles, and the relationship between the subsurface and surface velocities, in addition to the densimetric Froude and Reynolds numbers of the fine particles. We found that the dimensionless infiltration depth is not associated with hydraulic parameters or the weight of the fine sediment spilled; however, fine sediment deposition decreases with depth, and infiltration depth may increase if subsurface flow decreases over time. Finally, a relationship of the dimensionless maximum infiltration depth with the relative density of the mining particles, the ratio of the bed sediment and the mining particles sizes, and the ratio between the subsurface and surface velocities is established.

scholarly journals The complexities of measuring fine sediment accumulation within gravel-bed rivers

2017 ◽  
Vol 33 (10) ◽  
pp. 1575-1584 ◽  
Author(s):  
S.E. Harper ◽  
I.D.L. Foster ◽  
D.M. Lawler ◽  
K.L. Mathers ◽  
M. McKenzie ◽  
...  
Keyword(s):  
Sediment Accumulation ◽  
Fine Sediment ◽  
Gravel Bed ◽  
Gravel Bed Rivers

scholarly journals Sensitivity Analysis Of Geographical River Boundary Layers

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Levent Yilmaz
Keyword(s):  
Sensitivity Analysis ◽  
Sediment Transport ◽  
Steady Flow ◽  
Boundary Layers ◽  
Frequency Of Occurrence ◽  
Gravel Bed ◽  
Channel Shape ◽  
Gravel Bed Rivers

Bank full discharge is generally considered to be the dominant steady flow which would generate the same regime channel  shape and dimensions as the natural sequences of flows would.  This is because investigation on the magnitude and frequency of sediment transport have determined that for stable rivers the flow which in the longer term transports most material has the same frequency of occurrence as bankfull flow.  For stable gravel-bed rivers, this is considered to be the 1.5-year flood.

scholarly journals In situmeasurements of fine sediment infiltration (FSI) in gravel‐bed rivers with a hydropeaking flow regime

2018 ◽  
Vol 44 (2) ◽  
pp. 433-448 ◽  
Author(s):  
Christoph Hauer ◽  
Patrick Holzapfel ◽  
Diego Tonolla ◽  
Helmut Habersack ◽  
Guido Zolezzi
Keyword(s):  
Flow Regime ◽  
Fine Sediment ◽  
Gravel Bed ◽  
Gravel Bed Rivers

Comparing gravel-bed rivers in paired urban and rural catchments of southeastern Pennsylvania

Geology ◽  
2000 ◽  
Vol 28 (1) ◽  
pp. 79-82 ◽  
Author(s):  
J. E. Pizzuto ◽  
W. C. Hession ◽  
M. McBride
Keyword(s):  
Gravel Bed ◽  
Gravel Bed Rivers

UNRAVELLING THE ROLE OF VEGETATION IN THE AVULSION HISTORY OF GRAVEL-BED RIVERS

2018 ◽  
Author(s):  
Daniel Donahue ◽  
◽  
José Antonio Constantine ◽  
Gregory B. Pasternack
Keyword(s):  
Gravel Bed ◽  
History Of ◽  
Gravel Bed Rivers

Unobstructed and Obstructed Turbulent Flow in Gravel Bed Rivers

2005 ◽  
Vol 131 (8) ◽  
pp. 635-645 ◽  
Author(s):  
Hans M. Tritico ◽  
Rollin H. Hotchkiss
Keyword(s):  
Turbulent Flow ◽  
Gravel Bed ◽  
Gravel Bed Rivers
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