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 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.

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>

Effect of Holding Time on Microstructure and Properties of VC/Fe Composite

2012 ◽  
Vol 723 ◽  
pp. 353-357
Author(s):  
Guo Jun Zhang ◽  
Zhi Ping Sun ◽  
Li Yan Zou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Relative Density ◽  
Bending Strength ◽  
Holding Time ◽  
Microstructure And Properties ◽  
Microstructure And Mechanical Properties ◽  
Relationship Of ◽  
The Relationship ◽  
Better Than

The microstructure and mechanical properties of samples were examined, and the relationship of structure and mechanical properties for VC/Fe composite sintered at different holding time were studied. Holding time can influence the mechanical properties, with the holding time rising, when the holding time is 80 min, the hardness is Max, it’s 10.71 GPa, the enhancing range is 37.66%; The relative density changes slower from 60 to 100 min; when the holding time is 60 minutes, fracture toughness and bending strength of material is 16.17 MPa•m 1/2 and 1070 MPa, it’s better than before.

scholarly journals Application of hydrological models for agri-environmental management based on international and national experiences

2014 ◽  
pp. 45-50
Author(s):  
Csaba Juhász ◽  
Csaba Pregun
Keyword(s):  
Line Drawing ◽  
Reynolds Numbers ◽  
Regulated River ◽  
Width Ratio ◽  
Hydrological Models ◽  
Level Width ◽  
Lower Status ◽  
Relationship Of ◽  
The Relationship ◽  
Determining Factor

The ecological restoration of surface water flows requires the use of complex GIS and hydrological models. The HEC -RAS and MIKE11 programs calculate the hydraulic characteristics of runoff using the geometry and bed resistance the of flows. The presentation of some possible applications made through an example of the Berettyó, which is an extremely regulated river. The river belongs to the meandering category by Parker's classification system, which uses the relationship of the slope-Froude number and the depth- width ratio. Three coefficient of the four determining factor (entrenchment ratio, slope of water level, width-depth ratio) also indicates a mediocre to high sinuosity, while the river regulations established nearly straight bed-line. The standard water flow rates and characteristics have been determined based on the modeled Froude and Reynolds numbers. The flow conditions shifted to the laminar type by the changed line drawing which is ecologically lower status. Based on the results the morphological and ecohydrological river rehabilitation is appropriate.

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 Assessing Controls on the Displacement of Tracers in Gravel-Bed Rivers

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1598 ◽  
Author(s):  
Daniel Vázquez-Tarrío ◽  
Ramon J. Batalla
Keyword(s):  
Channel Morphology ◽  
Flow Strength ◽  
Gravel Bed ◽  
Structure Flow ◽  
Gravel Bed Rivers ◽  
The One ◽  
Individual Grains ◽  
Event Based ◽  
The Relationship ◽  
Travel Length

Particle travel length is one of the main dimensions of bedload and strongly influences river morpho-dynamics, particularly when exploring the interactions between sediment transport and channel morphology. This process has been traditionally studied by using tagged stones that allow tracking the movement experienced by individual grains during transport episodes. In this paper, we relate measured particle travel lengths to flow metrics and river channel parameters. First, we link the event-based bedload volumes to the active-layer dimensions, and the product between the average bedload rates and the duration of competent flows. We then hypothesize that travel length depends on channel width, surface grain-size, particle size, bed structure, flow strength, and duration of competent flow. The results from this approach are, subsequently, tested with a set of tracer observations from eight rivers that were available in the literature. The relationship between travel length and flow metrics was found to be statistically strong and has the potential to allow us to quantitatively assess the one-day dynamics of particles moving along streambeds. We also analyzed the influence of channel morphology and bed structure and identified morphological signatures for particle transport in gravel-bed rivers.

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

scholarly journals Revisiting with a Relative-Density Calibration Approach the Determination of Growth Rates of Microorganisms by Use of Optical Density Data from Liquid Cultures

2010 ◽  
Vol 76 (5) ◽  
pp. 1683-1685 ◽  
Author(s):  
Hsiu-Li Lin ◽  
Chien-Chung Lin ◽  
Yi-Jen Lin ◽  
Hsiu-Chen Lin ◽  
Chwen-Ming Shih ◽  
...  
Keyword(s):  
Relative Density ◽  
Optical Density ◽  
Growth Rates ◽  
Growth Time ◽  
Density Data ◽  
Liquid Cultures ◽  
Relationship Of ◽  
The Relationship ◽  
Calibration Approach

ABSTRACT To solve the problems of measuring the growth rates of microorganisms from optical density (OD)-growth time plots, we used relative-density (RD) plots. The relationship of OD and RD was built from the diluted grown cultures. This method was satisfactorily applied to study the growth of Escherichia coli and the cyanobacterium Anabaena spiroides.

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