Journal articles: 'Sediment transport. Bed load'

1

Liu, Chun Rong, and Dao Lin Xu. "Bed Load Transport under Complex Flow." Advanced Materials Research 255-260 (May 2011): 3589–93. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.3589.

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In this paper, the backward-facing step flow and the sediment transport downstream step were studied experimentally. The critical incipient bed shear velocity is obtained by the results of bed shear velocity and sediment incipient probability. It was found that the critical incipient bed shear velocity depends on the flow structures under the complex flow. By using the new critical incipient bed shear obtained in this paper and calculating the Shields parameter based on instantaneous bed shear velocity, the bed load sediment transport rate downstream step was given. The time history of the bed profile downstream step was calculated by bed load sediment transport rate and compared that obtained by the digital images. Good agreement was observed.

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Samaga, Belle R., Kittur G. Ranga Raju, and Ramchandra J. Garde. "Bed Load Transport of Sediment Mixtures." Journal of Hydraulic Engineering 112, no. 11 (February 1986): 1003–17. http://dx.doi.org/10.1061/(asce)0733-9429(1986)112:11(1003).

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Zanke, Ulrich, and Aron Roland. "Sediment Bed-Load Transport: A Standardized Notation." Geosciences 10, no. 9 (September 16, 2020): 368. http://dx.doi.org/10.3390/geosciences10090368.

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Morphodynamic processes on Earth are a result of sediment displacements by the flow of water or the action of wind. An essential part of sediment transport takes place with permanent or intermittent contact with the bed. In the past, numerous approaches for bed-load transport rates have been developed, based on various fundamental ideas. For the user, the question arises which transport function to choose and why just that one. Different transport approaches can be compared based on measured transport rates. However, this method has the disadvantage that any measured data contains inaccuracies that correlate in different ways with the transport functions under comparison. Unequal conditions also exist if the factors of transport functions under test are fitted to parts of the test data set during the development of the function, but others are not. Therefore, a structural formula comparison is made by transferring altogether 13 transport functions into a standardized notation. Although these formulas were developed from different perspectives and with different approaches, it is shown that these approaches lead to essentially the same basic formula for the main variables. These are shear stress and critical shear stress. However, despite the basic structure of these 13 formulas being the same, their coefficients vary significantly. The reason for that variation and the possible effect on the bandwidth of results is identified and discussed. A further result is the finding that not only shear stress affects bed-load transport rates as is expressed by many transport formulas. Transport rates are also significantly affected by the internal friction of the moving sediment as well as by the friction fluid-bed. In the case of not fully rough flow conditions, also viscous effects and thus the Reynolds number becomes of importance.

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Matoušek, Václav, and Štěpán Zrostlík. "Bed Load Transport Modelling Using Kinetic Theory." E3S Web of Conferences 40 (2018): 05072. http://dx.doi.org/10.1051/e3sconf/20184005072.

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Intense transport of bed load is associated with highconcentrated sediment-laden flow over a plane mobile bed at high bed shear. Typically, the flow exhibits a layered internal structure in which a vast majority of sediment grains is transported through a collisional layer above the bed. Our investigation focuses on steady uniform open-channel flow with a developed collisional transport layer and combines modelling and experiment to relate integral quantities, as the discharge of solids, discharge of mixture, and flow depth with the longitudinal slope of the bed and the internal structure of the flow above the bed. In the paper, flow with the internal structure described by linear vertical distributions of granular velocity and concentration across the collisional layer is analyzed by a model based on the classical kinetic theory of granular flows. The model predicts the total discharge, the discharge of sediment, and the flow depth for given (experimentally determined) bed slope and thickness of collisional layer. The model also predicts whether the intefacial dense layer develops between the bed and the collisional layer and how thick it is. Model predictions are compared with results of intense bed-load experiment carried out for lightweight sediment in our laboratory tilting flume.

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Delis, A. I., and I. Papoglou. "Relaxation approximation to bed-load sediment transport." Journal of Computational and Applied Mathematics 213, no. 2 (April 2008): 521–46. http://dx.doi.org/10.1016/j.cam.2007.02.003.

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6

Matoušek, Václav, and Štěpán Zrostlík. "Collisional transport model for intense bed load." Journal of Hydrology and Hydromechanics 68, no. 1 (March 1, 2020): 60–69. http://dx.doi.org/10.2478/johh-2019-0027.

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AbstractIn an open channel with a mobile bed, intense transport of bed load is associated with high-concentrated sediment-laden flow over a plane surface of the eroded bed due to high bed shear. Typically, the flow exhibits a layered internal structure in which virtually all sediment grains are transported through a collisional layer above the bed. Our investigation focuses on steady uniform turbulent open-channel flow with a developed collisional transport layer and combines modelling and experiment to relate integral quantities, as the discharge of solids, discharge of mixture, and flow depth with the longitudinal slope of the bed and the internal structure of the flow above the bed.A transport model is presented which considers flow with the internal structure described by linear vertical distributions of granular velocity and concentration across the collisional layer. The model employs constitutive relations based on the classical kinetic theory of granular flows selected by our previous experimental testing as appropriate for the flow and transport conditions under consideration. For given slope and depth of the flow, the model predicts the total discharge and the discharge of sediment. The model also predicts the layered structure of the flow, giving the thickness of the dense layer, collisional layer, and water layer. Model predictions are compared with results of intense bed-load experiment carried out for lightweight sediment in our laboratory tilting flume.

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Cardenas, M., J. Gailani, CK Zeigler, and W. Lick. "Sediment transport in the lower Saginaw River." Marine and Freshwater Research 46, no. 1 (1995): 337. http://dx.doi.org/10.1071/mf9950337.

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A study of the resuspension, deposition and transport of sediments and the resulting changes in bathymetry in the lower part of the Saginaw River in Michigan has been made. The numerical model used in this study consists of a two-dimensional, vertically integrated, time-dependent hydrodynamic and transport model coupled with a three-dimensional, time-dependent model of the dynamics of the sediment bed and its properties. Transport of sediment as suspended load and bed load was included in the analysis. In the numerical calculations, curvilinear coordinates were used. For verification of the model, results of numerical calculations of changes in the thickness of the sediment bed due to time-varying flow events were compared with bathyrnetric measurements taken at nine transects on the river on 28 August 1991 and 13 May 1992. From the transect measurements, from measurements of flow rates and sediment concentrations, and from the numerical modelling, a reasonably accurate description of the sediment transport and the resulting bathymetric changes has been made. The calculations and observations show that resuspension/deposition, bed load, and slumping are significant factors in changing the bathymetry. It is also shown that the largest flows are responsible for most of the sediment erosion and deposition and must therefore be understood and considered in detail. An approximate procedure for making long-term (1 to 25 year) calculations is presented and discussed. This procedure greatly reduces the required computer time but still maintains the required accuracy for the prediction of sediment and contaminant transport and fate.

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Wu, Weiming, and Qianru Lin. "A MULTIPLE-SIZED TRANSPORT FORMULA FOR NONUNIFORM SEDIMENTS UNDER CURRENT AND WAVES." Coastal Engineering Proceedings 1, no. 33 (December 14, 2012): 34. http://dx.doi.org/10.9753/icce.v33.posters.34.

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Nonuniform sediment transport exhibits difference from uniform sediment, even when the mean grain size is the same for both cases. The hiding, exposure, and armoring among different size fractions in the nonuniform bed material may significantly affect sediment transport, morphological change, bed roughness, wave dissipation, etc. It is necessary to develop multiple-sized sediment transport capacity formula to improve the accuracy and reliability of coastal analysis tools. The Wu et al. (2000) formula, which was developed for river sedimentation, is herein extended to calculate multiple-sized sediment transport under current and waves for coastal applications. This formula relates bed-load transport to the grain shear stress and suspended-load transport to the energy of the flow system. It considers the effect of bed material size composition in the hiding and exposure correction factor, which is omitted in many other existing formulas. Methods have been developed in this study to determine the bed shear stress due to waves only and combined current and waves, and in turn to compute the bed-load and suspended-load transport rates using the Wu et al. (2000) formula without changing its original formulation. The enhanced bed-load formula considers the effect of wave asymmetry on sediment transport, calculates the onshore and offshore bed-load transport rates separately and then derives the net transport rate, whereas the enhanced suspended-load formula calculates only the net transport rate due to the limit of available data. The formula has been tested using the single-sized and multiple-sized sediment transport data sets. The formula provides reliable predictions in both fractional and total transport rates. More than half of the test cases are predicted within a factor of 2 of the measured values, and more than 90% of the cases are within a factor of 5. This accuracy is generally reasonable for sediment transport under current and waves, which is very complex and little understood.

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CHARAFI, MY M., A. SADOK, A. KAMAL, and A. MENAI. "QUASI-THREE-DIMENSIONAL MATHEMATICAL MODELING OF MORPHOLOGICAL PROCESSES BASED ON EQUILIBRIUM SEDIMENT TRANSPORT." International Journal of Modern Physics C 11, no. 07 (October 2000): 1425–36. http://dx.doi.org/10.1142/s0129183100001267.

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A quasi-three-dimensional mathematical model has been developed to study the morphological processes based on equilibrium sediment transport method. The flow velocities are computed by a two-dimensional horizontal depth-averaged flow model (H2D) in combination with logarithmic velocity profiles. The transport of sediment particles by a flow water has been considered in the form of bed load and suspended load. The bed load transport rate is defined as the transport of particles by rolling and saltating along the bed surface and is given by the Van Rijn relationship (1987). The equilibrium suspended load transport is described in terms of an equilibrium sediment concentration profile (ce) and a logarithmic velocity (u). Based on the equilibrium transport, the bed change rate is given by integration of the sediment mass-balance equation. The model results have been compared with a Van Rijn results (equilibrium approach) and good agreement has been found.

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10

Roarty, Hugh J., and Michael S. Bruno. "Laboratory Measurements of Bed Load Sediment Transport Dynamics." Journal of Waterway, Port, Coastal, and Ocean Engineering 132, no. 3 (May 2006): 199–211. http://dx.doi.org/10.1061/(asce)0733-950x(2006)132:3(199).

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11

Wiberg, Patricia L., and J. Dungan Smith. "Model for Calculating Bed Load Transport of Sediment." Journal of Hydraulic Engineering 115, no. 1 (January 1989): 101–23. http://dx.doi.org/10.1061/(asce)0733-9429(1989)115:1(101).

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12

Seng Low, Heng. "Effect of Sediment Density on Bed‐Load Transport." Journal of Hydraulic Engineering 115, no. 1 (January 1989): 124–38. http://dx.doi.org/10.1061/(asce)0733-9429(1989)115:1(124).

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13

Damgaard, Jesper S., Richard J. S. Whitehouse, and Richard L. Soulsby. "Bed-Load Sediment Transport on Steep Longitudinal Slopes." Journal of Hydraulic Engineering 123, no. 12 (December 1997): 1130–38. http://dx.doi.org/10.1061/(asce)0733-9429(1997)123:12(1130).

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14

Sumer, B. Mutlu, Lloyd H. C. Chua, N. S. Cheng, and Jørgen Fredsøe. "Influence of Turbulence on Bed Load Sediment Transport." Journal of Hydraulic Engineering 129, no. 8 (August 2003): 585–96. http://dx.doi.org/10.1061/(asce)0733-9429(2003)129:8(585).

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15

Phillips, Brett C., and Alex J. Sutherland. "Spatial lag effects in bed load sediment transport." Journal of Hydraulic Research 27, no. 1 (January 1989): 115–33. http://dx.doi.org/10.1080/00221688909499247.

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Phillips, B. C., and A. J. Sutherland. "Temporal lag effect in bed load sediment transport." Journal of Hydraulic Research 28, no. 1 (January 1990): 5–23. http://dx.doi.org/10.1080/00221689009499144.

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17

Török, Gergely T., János Józsa, and Sándor Baranya. "Validation of a Novel, Shear Reynolds Number Based Bed Load Transport Calculation Method for Mixed Sediments against Field Measurements." Water 11, no. 10 (September 30, 2019): 2051. http://dx.doi.org/10.3390/w11102051.

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In this study, the field measurement-based validation of a novel sediment transport calculation method is presented. River sections with complex bed topography and inhomogeneous bed material composition highlight the need for an improved sediment transport calculation method. The complexity of the morphodynamic features (spatially and temporally varied bed material) can result in the simultaneous appearance of the gravel and finer sand dominated sediment transport (e.g., parallel bed armoring and siltation) at different regions within a shorter river reach. For the improvement purpose of sediment transport calculation in such complex river beds, a novel sediment transport method was elaborated. The base concept of it was the combined use of two already existing empirical sediment transport models. The method was already validated against laboratory measurements. The major goal of this study was the verification of the novel method with a real river case study. The combining of the two sediment transport models was based on the implementation of a recently presented classification method of the locally dominant sediment transport nature (gravel or sand transport dominates). The results were compared with measured bed change maps. The verification clearly referred to the meaningful improvement in the sediment transport calculation by the novel manner in the case of spatially varying bed content.

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Rafsanjani, Hardhi. "Sediment Transport Analysis of Sesayap River, Malinau District, North Kalimantan." Journal of the Civil Engineering Forum 3, no. 3 (September 18, 2017): 149. http://dx.doi.org/10.22146/jcef.27239.

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River could have a very important role in improving the economy of a country when it is correctly and properly utilized. Nevertheless, rivers in Indonesia also have various problems, i.e. erosion and sedimentation which occur in many Indonesian rivers, one of it being the Sesayap River. Because of these problems, it is very important to do analysis on bed load transport, in order to find its amount in the existing river, so that optimal handling on the occurring erosion and sedimentation problems could be performed. This research aimed to obtain the amount of bed load transport in Sesayap River, and then compare it to the field condition. The approaches used in this bed load transport analysis were Einstein approach and Frijlink approach, with data required for the analysis, which was water level elevation, topography data, and sediment gradation data. Based on the result of conducted bed load transport analysis, the bed load transport analysis result in Seluwing area was higher than in the Port area. Therefore, sediment deposition or sedimentation would occur in the river segment on between both locations. Qualitatively or tendentiously, the above results showed consistency with what actually happened, or observed, in the field. If it assumed that the equivalent diameter of bed load is 8 mm, the total of bed load transport on Seluwing area and Port area with Einstein approach are 1,582,263 m3 and 1,219,181 m3. Therefore, the sedimentary deposit per day could be calculated by calculating difference of bed load transport volume divided with total of the calculation day; which resulted sedimentary deposit per day of 2,859 m3. Whereas by using the Frijlink approach, the total of bed load transport on Seluwing area and Port area were of 1,391,940 m3 and 1,080,200 m3, and sedimentary deposit per day of 2,455m3. Based on the results, in order to normalize the Sesayap River, the dredging needed is 2,859m3/day based on Einstein approach and 2,455m3/day based on Frijlink approach.

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19

ESCAURIAZA, CRISTIAN, and FOTIS SOTIROPOULOS. "Lagrangian model of bed-load transport in turbulent junction flows." Journal of Fluid Mechanics 666 (January 6, 2011): 36–76. http://dx.doi.org/10.1017/s0022112010004192.

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Motivated by the need to gain fundamental insights into the mechanisms of bed-load sediment transport in turbulent junction flows, we carry out a computational study of Lagrangian dynamics of inertial particles initially placed on the bed upstream of a surface-mounted circular cylinder in a rectangular open channel (Dargahi, J. Hydraul. Engng, vol. 116, 1990, pp. 1197–1214). The flow field at Re = 39000 is simulated using the detached eddy simulation (DES) approach (Spalart et al., In Advances in DNS/LES, ed. C. Liu & Z. Liu, 1997, Greyden), which has already been shown to accurately resolve most of the turbulent stresses produced by the low-frequency, bimodal fluctuations of the turbulent horseshoe vortex (Paik et al., J. Hydraul. Engng, vol. 131, 1990, pp. 441–456; Escauriaza & Sotiropoulos, Flow Turbul. Combust., 2010, in press). The trajectory and momentum equations for the sediment particles are integrated numerically simultaneously with the flow governing equations assuming one-way coupling and neglecting particle-to-particle interactions (dilute flow) but taking into account bed–particle interactions and the effects of the instantaneous hydrodynamic forces induced by the resolved fluctuations of the coherent vortical structures. The computed results show that, in accordance with the simulated clear-water scour condition (i.e. the magnitude of the particle stresses is near the threshold of motion), the transport of sediment grains is highly intermittent and exhibits essentially all the characteristics of bed-load sediment transport observed in laboratory and field experiments. Groups of sediment grains are dislodged from the bed simultaneously in seemingly random bursting events and begin to move, saltating or sliding along the bed. Furthermore, particles that are not entrained into the bed-load layer are found to form streaks aligned with near-wall vortices around the cylinder. The global transport of particles is studied by performing a statistical analysis of the bed-load flux to reveal scale-invariance of the process and multifractality of particle transport as the overall effect of the coherent structures of the flow. A major finding of this work is that a relatively simple Lagrangian model coupled with a coherent-structure resolving simulation of the turbulent flow is able to reproduce the sediment dynamics observed in multiple experiments performed under similar conditions, and provide fundamental information on the initiation of motion and the multifractal nature of bed-load transport processes. The results also motivate the development of new Eulerian bed-load transport models that consider unsteady conditions and incorporate the intermittency of the unresolved scales of sediment motion.

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Almedeij, Jaber, and Panayiotis Diplas. "Bed load sediment transport in ephemeral and perennial gravel bed streams." Eos, Transactions American Geophysical Union 86, no. 44 (2005): 429. http://dx.doi.org/10.1029/2005eo440002.

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21

Misset, Clément, Alain Recking, Cédric Legout, Alain Poirel, and Marine Cazilhac. "Geomorphological factors influencing hysteresis patterns between suspended load and flow rate in Alpine rivers." E3S Web of Conferences 40 (2018): 04004. http://dx.doi.org/10.1051/e3sconf/20184004004.

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Suspended sediment load represents a large part of total solid fluxes transported in most rivers. Thus, for hydropower plan management or for environmental issues, it is crucial to understand how these sediments are produced, stored and transported in a given catchment. Hysteresis loops in discharge-suspended load signals are commonly used to assess sediment sources and production processes but most of the time the shape of this relation is analyzed qualitatively on short time series or for few events. In this study we analyzed quantitatively 10 long time series of suspended sediment load of various alpine catchments. This method allows us to compare events and to assess to which extent fine sediments originate from hillslope erosion processes or from river bed remobilization. We found that watersheds with braided bed morphology are dominated by clockwise loops while those with narrower bed as step-pool morphology are dominated by counter-clockwise hysteresis or have no general trend. These results suggest that storage and remobilization of fine sediments within the bed could play a major role in suspended sediment transport in Alpine streams, especially in large braided rivers.

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22

Saleh, A., I. Abustan, Mohd Remy Rozainy M. A. Z., and N. Sabtu. "Sediment Transport and Characteristics in Perak River and Kurau River." International Journal of Engineering & Technology 7, no. 2.29 (May 22, 2018): 849. http://dx.doi.org/10.14419/ijet.v7i2.29.14270.

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Particle size is the most important parameter to deal in sediment transport processes. This parameter is important to determine the class of sediment transport in river. It is also important for the selection of site for sand mining operation through the determination of the size of sediment, sediment capacity and sediment replenishment rate. Data were obtained through observations made from two rivers namely Sungai Perak and Sungai Kurau in Malaysia. The rivers were categorized as wide river for Sungai Perak and small river for Sungai Kurau. For Sungai Perak, the width of river ranges from 248.18 to 338.53 meter whilst the width of Sungai Kurau ranges from 9 to 11 meter. Data covers flow discharges from 130.988 m3/s to 435.915 m3/s for Sungai Perak and from 2.52 m3/s to 4.723 m3/s for Sungai Kurau. Based on the results, the bed load of two rivers are found to be mostly uniform mixture. The results indicate that these two Malaysian rivers mostly have uniform bed load The bed material for the two rivers are poorly graded mixture and the median size of bed loads mostly ranges from 0.62 to 2.94 mm.

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23

Bogen, Jim. "Glacial Sediment Production and Development of Hydro-Electric Power in Glacierized Areas." Annals of Glaciology 13 (1989): 6–11. http://dx.doi.org/10.1017/s0260305500007539.

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This paper discusses the results of a sediment-monitoring programme carried out in connection with hydro-electric power development plans in the river basins surrounding the Jostedalsbreen ice cap in Norway. Whereas the highest suspended-sediment transport rates occur during years with several flash-flood events, the bed load is more dependent upon the duration of large magnitude flood events. Bed-load transport has been obtained from annual measurements of deltaic growth in small lakes at the front of glaciers. During the years 1968–86, the mean ratio of bed load to total load amounted to 0.30–0.50% of the total load, but in years with large magnitude floods this ratio decreased. The mean annual suspended sediment yield of Norwegian glaciers ranges from 100 tonnes km2 a−1 to 1300 tonnes km2 a−1. Valley glaciers cause the highest erosion rates, with the exception of the small cirque glacier, Trollbergdalsbreen, which is thought to be a soft bed glacier. The investigation programme undertaken involved monitoring the volume of suspended sediments, together with the size distribution, mineralogy and shape of grains. In general, the valley glaciers supply more sand than the smaller cirque glaciers, whereas particles in the fine sand and silt-size ranges in almost all of the glaciers are angular in shape. Methods of comparing the abrasive capacity of the sediment load at various intakes in a power plant are discussed. Long-term sediment supply from the glaciers was investigated by studies of varves and rythmites in sediment cores from glacier-fed lakes.

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Bogen, Jim. "Glacial Sediment Production and Development of Hydro-Electric Power in Glacierized Areas." Annals of Glaciology 13 (1989): 6–11. http://dx.doi.org/10.3189/s0260305500007539.

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This paper discusses the results of a sediment-monitoring programme carried out in connection with hydro-electric power development plans in the river basins surrounding the Jostedalsbreen ice cap in Norway. Whereas the highest suspended-sediment transport rates occur during years with several flash-flood events, the bed load is more dependent upon the duration of large magnitude flood events. Bed-load transport has been obtained from annual measurements of deltaic growth in small lakes at the front of glaciers. During the years 1968–86, the mean ratio of bed load to total load amounted to 0.30–0.50% of the total load, but in years with large magnitude floods this ratio decreased. The mean annual suspended sediment yield of Norwegian glaciers ranges from 100 tonnes km2 a−1 to 1300 tonnes km2 a−1. Valley glaciers cause the highest erosion rates, with the exception of the small cirque glacier, Trollbergdalsbreen, which is thought to be a soft bed glacier. The investigation programme undertaken involved monitoring the volume of suspended sediments, together with the size distribution, mineralogy and shape of grains. In general, the valley glaciers supply more sand than the smaller cirque glaciers, whereas particles in the fine sand and silt-size ranges in almost all of the glaciers are angular in shape. Methods of comparing the abrasive capacity of the sediment load at various intakes in a power plant are discussed. Long-term sediment supply from the glaciers was investigated by studies of varves and rythmites in sediment cores from glacier-fed lakes.

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Zhijing, Li, Li Dazhi, Liu Xiaobin, Jin Zhongwu, and Chen Dasong. "Relative Transportability for Non-uniform Bed Load Sediment Transport." IOP Conference Series: Earth and Environmental Science 153 (May 2018): 042006. http://dx.doi.org/10.1088/1755-1315/153/4/042006.

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Yang, Haiyan, Binliang Lin, Jian Sun, and Guoxian Huang. "Simulating Laboratory Braided Rivers with Bed-Load Sediment Transport." Water 9, no. 9 (September 8, 2017): 686. http://dx.doi.org/10.3390/w9090686.

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Mieras, Ryan S., Jack A. Puleo, Dylan Anderson, Daniel T. Cox, Tian-Jian Hsu, and Joe Calantoni. "OBSERVATIONS OF HORIZONTAL AND VERTICAL SEDIMENT FLUXES ON A SANDBAR IN THE SUSPENDED AND SHEET FLOW LAYERS." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 30. http://dx.doi.org/10.9753/icce.v36.sediment.30.

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The majority of prior sandbar migration studies have been conducted from the morphological standpoint, whereby, (i) bathymetric profiles are recorded over periods of time ranging from days to decades, at frequencies ranging from hourly to yearly (Ruessink et al., 2003), and (ii) hydrodynamic observations typically consist of far-field wave and environmental conditions. Subsequent modeling efforts have generally focused on tuning parameters in the sediment transport formulations (suspended load and bed load) to maximize model skill in predicting observed beach profiles over time (FernÃ¡ndez-Mora et al., 2015; Hoefel and Elgar, 2003). However, little emphasis at the operational level has been placed on tuning coastal morphology models to the true relative contributions of the physical processes (e.g. suspended load, bed load and/or sheet flow) that drive the changing bathymetry. This is due, in part, to the lack of detailed sediment transport observations (field and lab) under realistic wave forcing conditions and spatially variable bathymetry. Such a modeling approach leads to the improper quantification (magnitude and/or direction) of each modeled sediment transport component under skewed-asymmetric and/or breaking waves, often observed in the surf zone. The present study aims to better understand the physical mechanisms responsible for driving cross-shore sediment transport over a sandbar by quantifying (a) the vertical exchange of sediment at the near-bed interface (i.e. pick-up layer), and (b) intra-wave horizontal sediment fluxes in the suspended load and sheet layers.

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Chandler, T. J., and R. A. Kostaschuk. "Test of selected bed-material load transport models: Nottawasaga River, Ontario." Canadian Journal of Civil Engineering 21, no. 5 (October 1, 1994): 770–77. http://dx.doi.org/10.1139/l94-083.

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Predictions from 13 bed-material load sediment transport models are compared with 19 measurements of bed-material transport in Nottawasaga River, Ontario, using summary plots and geometric statistics. Model selection is based on recent engineering application and suitability for the flow and sediment conditions of the river. The models of Laursen (1958) and Yang (1979) perform best, followed by those of Ackers and White (1973). The models of Van Rijn (1984), Maddock (1976), Karim and Kennedy (1983), Brownlie (1981), and Yang (1973) have considerable data scatter. The models of Engelund and Hansen (1967) and Shen and Hung (1972) are the poorest predictors. Poor model performance is primarily due to overestimation of flow strength needed for particle entrainment and an excessively steep slope in the relations between flow strength and sediment transport. Key words: bed-material load transport models, test, Nottawasaga River.

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Ma, Hongbo, Jeffrey A. Nittrouer, Baosheng Wu, Michael P. Lamb, Yuanfeng Zhang, David Mohrig, Xudong Fu, et al. "Universal relation with regime transition for sediment transport in fine-grained rivers." Proceedings of the National Academy of Sciences 117, no. 1 (December 18, 2019): 171–76. http://dx.doi.org/10.1073/pnas.1911225116.

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Fine-grained sediment (grain size under 2,000 μm) builds floodplains and deltas, and shapes the coastlines where much of humanity lives. However, a universal, physically based predictor of sediment flux for fine-grained rivers remains to be developed. Herein, a comprehensive sediment load database for fine-grained channels, ranging from small experimental flumes to megarivers, is used to find a predictive algorithm. Two distinct transport regimes emerge, separated by a discontinuous transition for median bed grain size within the very fine sand range (81 to 154 μm), whereby sediment flux decreases by up to 100-fold for coarser sand-bedded rivers compared to river with silt and very fine sand beds. Evidence suggests that the discontinuous change in sediment load originates from a transition of transport mode between mixed suspended bed load transport and suspension-dominated transport. Events that alter bed sediment size near the transition may significantly affect fluviocoastal morphology by drastically changing sediment flux, as shown by data from the Yellow River, China, which, over time, transitioned back and forth 3 times between states of high and low transport efficiency in response to anthropic activities.

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Liu, Yan, Christiane Zarfl, Nandita B. Basu, Marc Schwientek, and Olaf A. Cirpka. "Contributions of catchment and in-stream processes to suspended sediment transport in a dominantly groundwater-fed catchment." Hydrology and Earth System Sciences 22, no. 7 (July 19, 2018): 3903–21. http://dx.doi.org/10.5194/hess-22-3903-2018.

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Abstract. Suspended sediments impact stream water quality by increasing the turbidity and acting as a vector for strongly sorbing pollutants. Understanding their sources is of great importance to developing appropriate river management strategies. In this study, we present an integrated sediment transport model composed of a catchment-scale hydrological model to predict river discharge, a river-hydraulics model to obtain shear stresses in the channel, a sediment-generating model, and a river sediment-transport model. We use this framework to investigate the sediment contributions from catchment and in-stream processes in the Ammer catchment close to Tübingen in southwestern Germany. The model is calibrated to stream flow and suspended-sediment concentrations. We use the monthly mean suspended-sediment load to analyze seasonal variations of different processes. The contributions of catchment and in-stream processes to the total loads are demonstrated by model simulations under different flow conditions. The evaluation of shear stresses by the river-hydraulics model allows the identification of hotspots and hot moments of bed erosion for the main stem of the Ammer River. The results suggest that the contributions of suspended-sediment loads from urban areas and in-stream processes are higher in the summer months, while deposition has small variations with a slight increase in summer months. The sediment input from agricultural land and urban areas as well as bed and bank erosion increase with an increase in flow rates. Bed and bank erosion are negligible when flow is smaller than the corresponding thresholds of 1.5 and 2.5 times the mean discharge, respectively. The bed-erosion rate is higher during the summer months and varies along the main stem. Over the simulated time period, net sediment trapping is observed in the Ammer River. The present work is the basis to study particle-facilitated transport of pollutants in the system, helping to understand the fate and transport of sediments and sediment-bound pollutants.

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Török, Gergely T., János Józsa, and Sándor Baranya. "A Shear Reynolds Number-Based Classification Method of the Nonuniform Bed Load Transport." Water 11, no. 1 (January 3, 2019): 73. http://dx.doi.org/10.3390/w11010073.

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The aim of this study is to introduce a novel method which can separate sand- or gravel-dominated bed load transport in rivers with mixed-size bed material. When dealing with large rivers with complex hydrodynamics and morphodynamics, the bed load transport modes can indicate strong variation even locally, which requires a suitable approach to estimate the locally unique behavior of the sediment transport. However, the literature offers only few studies regarding this issue, and they are concerned with uniform bed load. In order to partly fill this gap, we suggest here a decision criteria which utilizes the shear Reynolds number. The method was verified with data from field and laboratory measurements, both performed at nonuniform bed material compositions. The comparative assessment of the results show that the shear Reynolds number-based method operates more reliably than the Shields–Parker diagram and it is expected to predict the sand or gravel transport domination with a <5% uncertainty. The results contribute to the improvement of numerical sediment transport modeling as well as to the field implementation of bed load transport measurements.

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Roth, Anita, Mona Jafarnejad, Sebastian Schwindt, and Anton Schleiss. "Design optimization of permeable sediment traps for fluvial bed load transport." E3S Web of Conferences 40 (2018): 03009. http://dx.doi.org/10.1051/e3sconf/20184003009.

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Sediment traps are crucial elements for flood protection in mountain rivers with high sediment transport capacity. Existing structures often interrupt the channel connectivity. Ideally, a sediment trap should be permeable for bed load during non-hazardous floods and ensure sediment retention during hazardous discharges. A new sediment trap concept, fulfilling these requirements was recently developed and tested in a laboratory flume. A guiding channel trough the deposition area is combined with a slot check dam having an upstream bar screen with bottom clearance. This study aims to validate the proposed concept with a finer sediment mixture on an experimental set-up. Furthermore, we provide improved recommendations for bar screen design regarding minimal bar spacing and the range of applicable clearance heights. Optimal bar spacing and clearance heights of the bar screen are determined through individual tests of the bar screen with steady discharges and varying sediment supply intensity. The best performing bar screen configuration is subsequently tested in combination with a slot check dam using a flood hydrograph to simulate the influence of quasi-unsteady discharge. The proposed concept corresponds to a combined mechanical-hydraulic control and works well for a large range of grain sizes, if the bar screen is correctly adapted.

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Jarocki, Walenty. "WAVE EFFECT ON THE COAST FORMATION AND EROSION." Coastal Engineering Proceedings 1, no. 7 (January 29, 2011): 12. http://dx.doi.org/10.9753/icce.v7.12.

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Various authors explain differently the mechanism of action of waves on the_ sediment movement. Some authors consider that the waves are raising the soil fractions from the bottom and water currents transfer them along the seaboard. The other authors suppose that each wave shears some soil in the bottom in littoral zone of the waves and wind is oblique to the shoreline. Beach currents catch and transport the sediment particles along the seaboard. These authors suppose when the wind is in the direction of seaboard /from sea/ then the bottom currents move in the opposite direction. These currents transport the ground particles in the direction of sea and thus the seaboard erosion arises. When the wind direction is opposite, the botto currents arise in the direction of seaboard and they cause the transportation of ground and the accumulation of seaboards. These reasons show that the action of waves would cause only the separation of ground particles and their asoeading. Our last investigations and observations of the sediment movement have led the conclusion that the waves may cause the raise of the sediment partciles and also their transport. The character of this transport depends on the wave kind and on the height and length of waves. General quantity of the lifted particles by means of waves increases as the power of waves or height and length of waves increases. If the power of waves decreases these particles fall. The waves are able to transport the bed load and detritus load without cooperation of the water current in spite of horizontal or inclined bottom. Under the action of waves the sediment moves the oscillatory movement. The waves move the bed load in the shallow exterior zones with the horizontal bottom only, towards the wave propagation. This material may be moved perpendicular the slope, according to the wave direction or in the opposite on< If the approaching wave creates the acute angle to the shoreline then the bed load moves near the seaboard. The transport of the bed load and of detritus loai change if the water current and waves appear simultaneously. The water current acts generally on the detritus load because the water moves this material easier than the bed load which rolls on the bottom.

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Fraccarollo, Luigi, and Marwan A. Hassan. "Einstein conjecture and resting-time statistics in the bed-load transport of monodispersed particles." Journal of Fluid Mechanics 876 (August 14, 2019): 1077–89. http://dx.doi.org/10.1017/jfm.2019.563.

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Sediment transport in rivers consists, at moderate discharge stage, of individual grains that undergo a series of step movements and rest periods (bed-load). Following a large number of grain trajectories in time and space is difficult and the results are affected by bias due to censorship of the time-spatial window. Therefore, the data sets available for the description of the statistics of resting-times, travel-time and lengths of the steps, are still insufficient. In this paper, an innovative experimental methodology has been designed and applied to get data representing the evolution of a bed surface and to support a robust statistical analysis of sediment transport. The methodology is based on image sequences taken of a flat bed made of well-sorted (mono-dispersed) particles. The acquired data are interpreted analytically through equations that describe the effects of grain entrainment and deposition. We show that grains’ displacement have a mean value independent of bed-load rate under low to moderate transport intensity for a given sediment type and bed-slope. Hence, we provide a strong validation of the seminal conjecture of Einstein in his theoretical statistical description of sediment transport. Finally, we describe the probability density functions of the resting-time for a few values of the sediment discharge.

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Yang, Zhengtong, Huajun Li, Bingchen Liang, Dongyoung Lee, Xinying Pan, and Yu Xu. "Laboratory Experiment on the Bed Load Sediment Transport over a Rippled Bed." Journal of Coastal Research 75, sp1 (March 3, 2016): 497–501. http://dx.doi.org/10.2112/si75-100.1.

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Jain, Ramandeep, Bernhard Vowinckel, and Jochen Fröhlich. "Impact of the regularity of the sediment bed on bed-load transport." PAMM 16, no. 1 (October 2016): 583–84. http://dx.doi.org/10.1002/pamm.201610280.

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37

Gomez, Basil, and Michael Church. "An assessment of bed load sediment transport formulae for gravel bed rivers." Water Resources Research 25, no. 6 (June 1989): 1161–86. http://dx.doi.org/10.1029/wr025i006p01161.

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38

Zanden, Joep van der, Dominic A. Van der A, Tom O'Donoghue, David Hurther, Ivan Caceres, Peter D. Thorne, Jebbe J. Van der Werf, Suzanne J. M. H. Hulscher, and Jan S. Ribberink. "SUSPENDED AND BEDLOAD TRANSPORT IN THE SURF ZONE: IMPLICATIONS FOR SAND TRANSPORT MODELS." Coastal Engineering Proceedings, no. 35 (June 23, 2017): 30. http://dx.doi.org/10.9753/icce.v35.sediment.30.

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This paper presents results obtained during a large-scale wave flume experiment focused at measuring hydrodynamics and sediment transport processes in the wave breaking region. The experiment involved monochromatic plunging breaking waves over a mobile bed barred profile consisting of D50 = 0.24 mm sand. Vertical profiles of velocity, turbulence, sand concentration and sand fluxes were measured at 12 cross-shore locations, covering the shoaling region up to the inner surf zone. Particularly high-resolution profiles were obtained near the bed within the wave bottom boundary layer, using an acoustic sediment concentration and velocity profiler (ACVP). Sheet flow concentration and particle velocities were measured at two locations near the bar crest using two conductivity-based concentration measurement tanks (CCM+). Total transport rates, obtained from the evolving bed profile measurements, were decomposed into suspended and bedload transport contributions across the bar. The present paper presents a summary of the key findings of the experiment, which are used to discuss existing approaches for modeling suspended and bed load transport in the surf zone.

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39

Duan, Zihao, Jie Chen, Changbo Jiang, Xiaojian Liu, and Bingbing Zhao. "Experimental Study on Uniform and Mixed Bed-Load Sediment Transport under Unsteady Flow." Applied Sciences 10, no. 6 (March 15, 2020): 2002. http://dx.doi.org/10.3390/app10062002.

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The scouring and deposition of sediment caused by unsteady flows (e.g., storm waves and floods) produces many secondary disasters. The resultant bed-load movement exhibits different transport laws compared with that by steady flow. In this study, the flume experiments were performed to study the bed-load movement under unsteady flow with different velocity skewness. The movement of uniform and non-uniform non-cohesive sediment under unsteady flow as well as the influence of the steady and unsteady flow on sediment transport rate are compared. Additionally, the non-uniform sediment transport formula of fine-to-coarse particle diameter ratio was investigated. The results showed that the sediment transport rate between uniform and non-uniform sand under the same median diameter is different. The non-uniform sediment transport rate is 1.27-, 3.19-, and 0.68-times as large as that in uniform sediment under d50 = 0.664, 1.333, and 2.639 mm under unsteady flow, respectively. For non-uniform sand, the transport rate of non-uniform sand with a larger adjacent particle size ratio (δ = 0.29) was 1.31-times greater than that of the non-uniform sand with a smaller adjacent particle size ratio (δ = 0.50). Moreover, theoretical deduction was carried out and the incipient sediment motion was analyzed from the force mechanism. A new unsteadiness parameter based on the acceleration concept was proposed. The relationship between the travel distance and velocity skewness of sediment particles was set up. The experimental results and theoretical analysis showed that sediment under unsteady flow were easier to start and transport than those under steady flow in the same flow effect. The travel distance of sediment particles was longer under unsteady flow than that under steady flow.

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40

Pradhan, S., R. N. Samal, S. B. Choudhury, and P. K. Mohanty. "HYDRODYNAMIC AND COHESIVE SEDIMENT TRANSPORT MODELING IN CHILIKA LAGOON." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-5 (November 15, 2018): 141–49. http://dx.doi.org/10.5194/isprs-annals-iv-5-141-2018.

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Abstract. Chilika lagoon, one of the largest brackish water lagoons in Asia located along the east coast of India. The rivers draining into the lagoon carry about 13 million tonnes of sediments annually. Because of the cohesiveness properties of the fine sediments, nutrients, heavy metals and other polluted substances tend to bind to the sediment’s surface. Consequently, pollutants can be concentrated in the inlets/estuaries, thus being of great environmental interest. In addition, the mudflats occurring are important biotopes for a large number of micro- and macro-faunal species and act as feeding places for a number of birds. To understand the cohesive sediment dynamics, a numerical model, MIKE 21 Mud Transport (MT) coupled with hydrodynamic (HD) was used. The model simulated the relative bed level height and suspended sediment concentrations. The sediment interchange and accumulation between each sectors and Bay of Bengal were evaluated. The suspended sediment concentration is high in the north-east portion of the lagoon while medium and low suspended loads are observed in the eastern and western portion of the lagoon. Bed thickness is very high in the north-western corner of the lagoon covered with Phragmites Karka which facilitate sediment trap. Total bed thickness change is very much pronounced in the northern sector which receives most of the sediments from the Mahanadi river systems as well along the periphery of the lagoon due to drainage. The eastern lagoon shows a net deposition accumulated fraction (5–15kg/m2) and hence gives enough indication of the sedimentation processes in the lagoon. Further, the results also warrant immediate attention to check and monitor suspended sediment concentration to find out the net deposition trend in the lagoon environment in order to take decisions in minimizing the sediment load.

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41

Lockwood, Kenneth, Patrick Grover, and Ana Maria Ferreira da Silva. "Quantification of bed-load transport over dunes." E3S Web of Conferences 40 (2018): 02010. http://dx.doi.org/10.1051/e3sconf/20184002010.

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There is disagreement in the literature as to whether a shear stress-based approach can be used to accurately predict sediment transport over dunes. This study aims to address this disagreement. To this end, use is made of an experiment involving the study of naturally formed, fully developed dunes produced in a laboratory flume. The bed shear stress is estimated through a combination of velocity, Reynolds stress measurements, and results of a CFD RANS rough wall model. The validity of using Bagnold’s equation to predict the bed-load rate is subsequently analyzed. In contrast to what has been previously suggested by some authors, it is found from the present experiment that the bed-load rate correlates well with the bed shear stress, and that Bagnold’s equation yields realistic values of the bed-load rate over the stoss side of the dune downstream of the reattachment point. This work also highlights the difficulties in reliably estimating the bed shear stress in complex flows. Such difficulties are overcome in this paper through a combination of flow velocity measurements and modeled results.

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42

Zhu, Zhang, and Chen. "Statistical Analysis of Bed Load Transport over an Armored Bed Layer with Cluster Microforms." Water 11, no. 10 (October 6, 2019): 2082. http://dx.doi.org/10.3390/w11102082.

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River engineers have long been challenged by the need to predict sediment transport, especially over armored riverbeds. This study investigates the statistical properties of bed load transport over an armored bed layer with cluster microforms in laboratory experiments. Particle clusters on the sediment bed were formed by widely graded particles under constant flow. A series of key kinematic parameters computed from particle trajectories recorded by a digital camcorder, including mean squared particle displacement (MSD), particle number activity, particle velocities, step length, and rest period, were analyzed. The scaling growth of the MSD with time showed that the particle diffusion regime was superdiffusive at small time scales, but became subdiffusive at larger time scales. The particle number activity follows a negative binomial distribution, and the probability distributions of streamwise and transverse particle velocities displayed heavy asymptotic tails, which indicates the particle clusters might exert a dual impact on bed load transport: some particles are accelerated in the preferential paths between particle clusters, while others were obstructed by the particle clusters. In addition, the bed load diffusion regime varied with observation time scales. The findings of this study can gain insight into the bed load transport processes over armored riverbeds.

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43

Hou, Ji, Chunze Zhang, Dan Wang, Feng Li, Zijian Yu, and Qin Zhou. "Fixed-Bed and Mobile-Bed Resistance of Channels with Steep Gradients in Mountainous Areas." Water 11, no. 4 (April 2, 2019): 681. http://dx.doi.org/10.3390/w11040681.

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Flood discharge and sediment transport are closely linked to channel resistance in steep mountain streams. Previous research has mainly focused on the resistance of fixed-bed channels with steep gradients and mobile-bed channels in alluvial rivers. The present study performs an experiment and establishes a calculation method for the fixed-bed resistance of mountain channels. The basic expression of the mobile-bed resistance of steep mountain channels is derived by determining the controlling factors of the bed load movement on the riverbed resistance. The proposed formula can accurately predict the variation of the bed load resistance. The results of the present research improve the understanding of fluid dynamics and sediment transport in steep mountain channels.

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44

Marinho, Rogério Ribeiro, Antonio Fábio Sabbá Guimarães Vieira, and Feliciano De Souza Maciel. "Análise Montante-Jusante da Granulometria dos Sedimentos de Fundo e Suspenso do Rio Negro e Tributários (Bacia Amazônica, Brasil)." Revista Brasileira de Geografia Física 14, no. 2 (April 14, 2021): 997. http://dx.doi.org/10.26848/rbgf.v14.2.p997-1008.

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O conhecimento das características físicas de sedimentos transportados por grandes sistemas fluviais possui significativa importância para o entendimento de processos geomorfológicos e hidrológicos. O nível de conhecimento dos grandes sistemas fluviais da Amazônia e sua relação com o transporte de sedimentos ainda é limitado, resultando em lacunas de conhecimento sobre a dinâmica da paisagem nesta complexa região. Este trabalho teve como objetivo avaliar a distribuição espacial da granulometria de sedimentos de fundo e suspenso do Rio Negro e tributários. Realizou-se análise da distribuição do tamanho dos sedimentos em seções amostrais localizadas no alto, médio e baixo curso do Rio Negro. Os resultados da análise granulométrica da carga de fundo indicam a predominância de sedimentos com tamanho variando de 0,25 a 1,0 mm (principalmente areia fina, areia média e areia grossa) enquanto no baixo curso as amostram oscilaram de areia fina a partículas lamosas (< 0,50 mm). No Rio Negro os sedimentos suspensos são compostos principalmente de partículas finas de silte (90% menor que 80 µm) com diâmetro mediano (D50) de 25 µm. As características granulométricas apresentadas neste trabalho fornecem subsídios para o entendimento de processos hidrodinâmicos de transporte e deposição dos sedimentos de fundo e suspenso neste gigante sistema fluvial. Upstream-downstream Granulometry Analysis of bed and suspended sediments in the Negro River Basin (Amazon Basin, Brazil)A B S T R A C TThe knowledge of the physical characteristics of sediments transported by large river systems has significant importance for the understanding of geomorphological and hydrological processes. The level of knowledge of the large rivers of the Amazon basin and their relationship with sediment transport is limited, resulting in gaps about the dynamics of the landscape in this complex region. This article analyzes the spatial distribution of granulometry of bed and suspended sediments in the Negro River and tributaries. An analysis of the sediment size distribution was carried out in sample sections located in the upper, middle and lower reaches of the Negro River. The results of the granulometric analysis of the bed load indicate the predominance of sediments with sizes ranging from 0.25 to 1.0 mm (mainly fine sand, medium sand and coarse sand) while in the low course they showed oscillated from fine sand to muddy particles (<0.50 mm). In the Negro River basin the suspended sediments are composed mainly of fine silt particles (90% less than 80 µm) with a median diameter (D50) of 25 µm. The granulometric characteristics presented in this work provide subsidies for the understanding of hydrodynamic processes of transport and deposition of bed and suspended sediments in this huge fluvial system.Keywords: sediment transport, Amazon floodplain, multichannel river, anabranching

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45

Ristenpart, E., R. M. Ashley, and M. Uhl. "Organic near-bed fluid and particulate transport in combined sewers." Water Science and Technology 31, no. 7 (April 1, 1995): 61–68. http://dx.doi.org/10.2166/wst.1995.0201.

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Studies in Germany, Belgium, France and Scotland have revealed that there are significant solids transport gradients in the depth of foul and combined sewage flows. Continuous field observations of changes in depths of sediment deposits in combined sewers have also indicated that there is an interaction between the erosion and deposition processes and changes in the mass transport of solids in regions in the overlying flow. A fuller understanding of the interactive phenomena is essential for both sewer sediment management and the minimization of associated pollution from wash-out of solids via CSOs. The paper presents results from the detailed studies in Hildesheim, Germany and those carried out in Dundee, Scotland, investigating the heterogeneity of solids movement with regard to gross solids, erosion of sewer sediments and their interactions with the suspended transport phases and the layer of very dense fluid found to be transported under certain circumstances, near the sediment bed or sewer invert (traditionally called ‘bed-load’).

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46

Rahman, Sabaruddin, Akira Mano, and Keiko Udo. "Quasi-2D sediment transport model combined with Bagnold-type bed load transport." Journal of Coastal Research 65 (January 2, 2013): 368–73. http://dx.doi.org/10.2112/si65-063.1.

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47

Leftheriotis, Georgios, and Athanassios Dimas. "LARGE-EDDY SIMULATION OF OSCILLATORY FLOW, SEDIMENT TRANSPORT AND MORPHODYNAMICS OVER RIPPLES." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 14. http://dx.doi.org/10.9753/icce.v36.sediment.14.

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In the present study, a well-resolved large-eddy simulation was coupled to a morphodynamical model in order to study the sediment dynamics induced by an oscillatory flow over a sandy bed, as well as the creation/evolution of ripples under hydrodynamic forcing. The simulations were based on the numerical solution of the Navier-Stokes equations for the flow, empirical formulas for the bed load, and the advection-diffusion equation for the suspended sediment. The evolution of the bed form was obtained by the numerical solution of the conservation of sediment mass equation. The Immersed Boundary method was implemented for the imposition of fluid and sediment boundary conditions on the moving bed surface. The model was effectively validated against laboratory measurements. Results are presented for ripple creation and propagation from a quasi-flat bed, as well as results of ripples adapting to water conditions.

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OURIEMI, MALIKA, PASCALE AUSSILLOUS, and ÉLISABETH GUAZZELLI. "Sediment dynamics. Part 1. Bed-load transport by laminar shearing flows." Journal of Fluid Mechanics 636 (September 25, 2009): 295–319. http://dx.doi.org/10.1017/s0022112009007915.

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We propose a two-phase model having a Newtonian rheology for the fluid phase and friction for the particle phase to describe bed-load transport in the laminar viscous regime. We have applied this continuum model to sediment transport by viscous shearing flows. The equations are shown to reduce to the momentum equation for the mixture and the Brinkman equation for the fluid velocity. This modelling is able to provide a description of the flow of the mobile granular layer. At some distance from threshold of particle motion, where the continuum approach is more realistic as the mobile layer is larger than one particle diameter, there is very little slip between the two phases and the velocities inside the mobile bed have approximately a parabolic profile. When the Poiseuille (or Couette) flow is not significantly perturbed, simple analytical results of the particle flux varying cubically with the Shields number and of the bed-load thickness varying linearly with it can then be obtained. These predictions compare favourably with experimental observations of bed-load transport in pipe flows.

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Tanaka, Hitoshi. "BED LOAD TRANSPORT DUE TO NON-LINEAR WAVE MOTION." Coastal Engineering Proceedings 1, no. 21 (January 29, 1988): 133. http://dx.doi.org/10.9753/icce.v21.133.

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The bed load transport rate due to wave motion is measured in a wave flume. The modified stream function theory of the author ( Tanaka (1988) ) is applied to the formulation of the sediment transport rate in order to include the non-linearity. The proposed formula predicts well except near the surf zone where the effect of the acceleration plays an important role.

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Hsu, Shaohua Marko, and Forrest M. Holly. "Conceptual Bed‐Load Transport Model and Verification for Sediment Mixtures." Journal of Hydraulic Engineering 118, no. 8 (August 1992): 1135–52. http://dx.doi.org/10.1061/(asce)0733-9429(1992)118:8(1135).

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Journal articles on the topic 'Sediment transport. Bed load'

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