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Non-equilibrium concentration profile formulas of suspended sediment and their preliminary applications

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International Journal of sediment Research 2022年第4期37卷 505-513页

作者： Zipu Ma Qingchao Guo Jianzhao Guan Maohua Le State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower Research Yellow River Institute of Hydraulic Research Yellow River Conservancy Commission of the Ministry of Water Resources

The vertical concentration profiles in non-equilibrium sediment transport processes generally deviate from the equilibrium concentration distribution of suspended sediment. The non-equilibrium concentration profile formulas currently available are those of Han and Brown, respectively. However, the complexity of these formulas limits their use in practical calculations. To improve the usefulness of these formulas, the unknown parameters in Han’s formula are reduced from three to two, and the three different forms of Brown’s formula are transformed into one. These formulas then are proved to be essentially the same to some extent, and only different in the expression form of the exponent. Han’s formula then is improved, based on which the theoretical calculation methods and distribution characteristics of non-equilibrium profiles are presented. Han’s and Brown’s formulas are verified qualitatively and quantitatively. Finally, these formulas are applied in the investigation of the characteristics of certain physical quantities, such as the recovery factor of sediment concentration, near-bottom sediment flux, and the non-equilibrium P eclet number in the non-equilibrium sediment transport process. These results clearly reveal that the magnitude of these physical quantities decreases in the erosion process and increases in the deposition process. The results also show that the formulas are largely applicable for the non-equilibrium sediment transport conditions.

关键词： suspended sediment Vertical concentration profiles Non-equilibrium sediment conditions Non-saturation parameter Péclet number

WAVE BOTTOM LAYERS DYNAMIC WITH suspended sediment OVER VORTEX RIPPLES

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Journal of Hydrodynamics 2004年第2期16卷 201-208页

作者： JIANGChang-bo BAIYu-chuan ZHAOZi-dan ZHANGHong-wu CollegeofRiverandOceanEngineeringChangshaUniversityofScienceandTechnology Changsha410076China InstituteofsedimentonRiverandCoastEngineering TianjinUniversityTianjin300072China SchoolofCivilEngineering TsinghuaUniversityBeijing100084China

Vortex ripple is widely formed in the coastal region, and the dynamic ofvortex is quite important because it is responsible for sediment transport. The flow structurearound the vortex ripples can be modeled as 2D flow due to the geometry of the flow boundaries. Inthis paper, 2D Large-Eddy-Simulation (LES) method was used to predict the flow structure and thedynamic of vortex in the bottom layers under the action of the wave, the numerical simulationresults show a completely process of vortex formation, evolvement and disappearance. Based on thestudy of flow structure, the suspended sediment transport was modeled in present paper. Thesimulated sediment concentrations were compared to measurements from the literature. The agreementbetween the time averaged simulated concentration profiles and measurements is satisfactory. For ahigh setting velocity, the suspended sediment is confined to the vicinity of the bed, and it isdominated by the local bottom shear stress. For a small setting velocity, the suspension is moredominated by the characteristic of vortex. There are two suspended sediment transport peaks observedin the cross-section at the trough and crest in the half period, the second peak is due to theseparation bubble taking the sediment.

关键词： wave boundary layer vortex ripple suspended sediment numerical model

HORIZONTAL 2-D BASIC EQUATIONS AND SIMULATION OF INTERCHANGE BETWEEN suspended sediment AND BED MATERIALS IN ALLUVIAL RIVER

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Journal of Hydrodynamics 2007年第4期19卷 509-516页

作者： ZHAO Lian-jun JIANG En-hui TAN Guang-ming WEI Zhi-lin Yellow River Institute of Hydraulic Research Zhengzhou 450003 China State Key Laboratory of Water Resource and Hydropower Engineering Sciecnce Wuhan University Wuhan 430072 China

A set of new 2-D equations of interchange between suspended sediment and bed materials was serived by theoretical deduction based on the systematic summarization and assessment the previous studies of simulating the interchange between suspended sediment and bed materials in the Lower Yellow River. This model was used to simulate the erosion and deposition processes caused by the interchange between suspended sediment and bed materials in a sketch channel. The results show that these equations are well consistent with the laws of interchange between suspended sediment and bed materials. Furthermore, compared with previous models, it has important practical value not only because of strong theoretical foundation, but also for smaller amount of calculating work and convenient application in practice.

关键词： horizontal 2-D suspended sediment bed materials sediment interchange erosion deposition

Modeling of suspended sediment transport with wave-induced longshore current in Huanghe (Yellow) River Delta

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Acta Oceanologica Sinica 2009年第3期28卷 65-74页

作者： LI Changliang LIANG Bingchen ZHANG Jing College of Petroleum Engineering China University of Petroleum（East China） Qingdao266555 China Engineering College Ocean University of China Qingdao 266100 China

A three-dimensional suspended sediment model （SED） developed by the present authors is coupled with the combinatorial model of COHERENS （Luyten et al., 1999）（the three-dimensional coupled hydrodynamical-ecological model for Regional and Shelf Seas） and SWAN （Holthuijsen et al., 2004）（the third generation wave model）. SWAN is regarded as a subroutine of COHERENS and gets time- and space-varying current velocity and surface elevation from COHERENS. COHERENS gets time- and space- varying wave relevant parameters provided by SWAN. Effects of wave on current are applied in bottom shear stress, wave-induced depth-dependent radiation stress and surface drag coefficient calculation. At the same time, the damping function of suspended sediment on turbulence is introduced into COHERENS. So the sediment model SED has feedback on circulation model COHERENS. The SED obtains current associated parameters from COHERENS. Then a coupled hydrodynamic-sediment model COHERENS-SED being able to account for interaction between wave and current is obtained. COHERENS-SED is adopted to simulate three-dimensional suspended sediment transport in the Huanghe River delta. In terms of simulation results, there is obvious difference between top and bottom layer of wave-induced longshore current. The values of time series of sediment concentration gotten by COHERENS-SED have, generally, an accepted agreement extent with measurement. Significant wave heights and wave periods obtained by COHERENS-SED show that wave simulation case with currentts effect can give better agreement extent with measurement than case without current＇s effect. In the meantime, suspended sediment concentration distributing rule obtained by COHERENS-SED is similar to former researches and measurement.

关键词： Huanghe River delta suspended sediment wave-induced longshore current COHERENS SWAN COHERENS-SED

Quantitative Application Study on Remote Sensing of suspended sediment

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China Ocean Engineering 2012年第3期26卷 483-494页

作者：陈一梅徐宿东林强 Department of Harbor Waterway and Coastal EngineeringSchool of TransportationSoutheast University

Quantitative application on remote sensing of suspended sediment is an important aspect of the engineering application of remote sensing study. In this paper, the Xiamen Bay is chosen as the study area. Eleven different phases of the remote sensing data are selected to establish a quantitative remote sensing model to map suspended sediment by using remote sensing images and the quasi-synchronous measured sediment data. Based on empirical statistics developed are the conversion models between instantaneous suspended sediment concentration and tidally-averaged suspended sediment concentration as well as the conversion models between surface layer suspended sediment concentration and＂ the depth-averaged suspended sediment concentration. On this basis, the quantitative application integrated model on remote sensing of suspended sediment is developed. By using this model as well as multi-temporal remote sensing images, multi-year averaged suspended sediment concentration of the Xiamen Bay are predicted. The comparison between model prediction and observed data shows that the multi-year averaged suspended sediment concentration of studied sites as well as the concentration difference of neighboring sites can be well predicted by the remote sensing model with an error rate of 21.61% or less, which can satisfy the engineering requirements of channel deposition calculation.

关键词： remote sensing suspended sediment multi-year averaged suspended sediment concentration integrated model Xiamen Bay

CALCULATION MODELS FOR THE suspended sediment TRANSPORT RATE

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Journal of Hydrodynamics 1993年第1期5卷 10-21页

作者： Ni, Jinren Peking Univ Beijing China

The calculation accuracy of the suspended sediment transport rate relies on that of the vertical distribution of the particle concentration,the particle velocity distribution and the reference concentration.In view of the limitations of the previons formulas for both the velocity and the concentration distributions,general expressions are introduced to the calculation of sus- pended sediment transport rate.Based on these analyses,a simple and practical calculation model is given in the present paper.

关键词： suspended sediment transport rate concentration profile

An integrated suspended sediment transport monitoring and analysis concept

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International Journal of sediment Research 2014年第2期29卷 135-148页

作者： Marlene HAIMANN Marcel LIEDERMANN Petra LALK Helmut HABERSACK Christian Doppler Laboratory for Advanced Methods in River Monitoring Modelling and EngineeringInstitute of Water ManagementHydrology and Hydraulic Engineering Department of WaterAtmosphere and EnvironmentBOKU-University of Natural Resources and Life SciencesVienna

A new integrated suspended sediment monitoring strategy applying direct and indirect technologies is presented.Optical sensors continuously record the turbidity at one point in the channel cross section close to the river bank and are calibrated by water samples taken close to the sensor.Additionally measurements are performed to establish the distribution of suspended sediment in a cross section(bottle samples combined with acoustic devices).Using correction factors(probe and cross-sectional factor) these monitoring methods are combined and it is,thus,possible to fully document the temporal and spatial variability of the suspended sediment transport and to estimate the suspended sediment load for certain time periods.This monitoring strategy was implemented at various measurement sites in Austria as well as at the Hainburg Road Bridge site on the Danube River.It has already been successfully applied for three years at this measurement site and suspended sediment loads during high discharges up to a 15 year flood event have been monitored.To evaluate the new monitoring methods the results were compared with load estimation methods found in the literature including averaging and ratio estimators as well as rating curves.The results prove that with the new methodology,the temporal variability of the suspended sediment transport can be detected more accurately compared with the other methods.They also demonstrate that the additional consideration of the spatial distribution of the suspended sediment concentration in the cross section is crucial as the mean concentration in the cross section can significantly exceed the concentration near the banks,especially at large rivers like the Danube River.

关键词： suspended sediment Integrated suspended sediment monitoring programme Turbidity sensor Acoustic devices Load estimates

PREDICTION OF THE GRAIN SIZE OF suspended sediment:IMPLICATIONS FOR CALCULATING suspended sediment CONCENTRATIONS USING SINGLE FREQUENCY ACOUSTIC BACKSCATTER

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International Journal of sediment Research 2007年第1期22卷 1-15页

作者： R. A. KUHNLE D. G. WREN J. P. CHAMBERS Dr.Research Hydraulic Engineer National Sedimentation Laboratory U. S. Department of Agriculture Agricultural Research Service Oxford Mississippi 38655 USA Senior Research Scientist National Center for Physical Acoustics University of Mississippi University Mississippi 38677 USA

Collection of samples of suspended sediment transported by streams and rivers is difficult and expensive. Emerging technologies, such as acoustic backscatter, have promise to decrease costs and allow more thorough sampling of transported sediment in streams and rivers. Acoustic backscatter information may be used to calculate the concentration of suspended sand-sized sediment given the vertical distribution of sediment size. Therefore, procedures to accurately compute suspended sediment size distributions from easily obtained river data are badly needed. In this study, techniques to predict the size of suspended sand are examined and their application to measuring concentrations using acoustic backscatter data are explored. Three methods to predict the size of sediment in suspension using bed sediment, flow criteria, and a modified form of the Rouse equation yielded mean suspended sediment sizes that differed from means of measured data by 7 to 50 percent. When one sample near the bed was used as a reference, mean error was reduced to about 5 percent. These errors in size determination translate into errors of 7 to 156 percent in the prediction of sediment concentration using backscatter data from 1 MHz single frequency acoustics.

关键词： suspended sediment Grain size Acoustic backscatter Concentration errors

Grain-size distribution patterns of suspended sediment in response to hydrodynamics on the Dafeng intertidal flat, Jiangsu, China

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Acta Oceanologica Sinica 2006年第6期25卷 63-77页

作者： LI Zhanhai GAO Shu CHEN Shenliang WANG Yaping State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai 200062 China Key Laboratory of Coast and Island Development of Ministry of Education Nanjing University Nanjing 210093 China

Patterns of grain-size distributions of suspended sediment in relation to resuspension, settling, and tidal processes are investigated, based on in situ measurements over the Dafeng intertidal flat, on the Jiangsu coast, in the summer of 2002 and 2003. The suspended sediment here is dominated by fine and very fine silt, with a mean grain-size of 7 - 13 μm. The patterns of the grainsize distributions of suspended sediment during a tidal cycle are characterized by two types： one stable type representing insignificant spatial and temperal variations; and the other bimedal type with significant variations. The main factors influencing the grainsize distributions include resnspension, settling, suspended sediment imported into intertidal flats during the flood phase, and the grain-size distribution of seabed sediment. Resuspension increases the coarse particle content, enhances the mean grain-size of suspended sediment, and results in grain-size distributions for the suspended sediment similar to those of seabed sediment; the settling process has opposite effects on the suspended sediment. When resuspension occurs, the gain-size distributions of suspended sediment in the lower part of water column respond significantly to the current velocity. Where the influence of resuspension and settling processes is weak, the grain-size distributions of suspended sediment appear to be stable and almost identical for the various parts of intertidal flats during different measurement periods. Such distributions are referred to the background grain-size distribution, for which the mean grain-size over the Dafeng intertidal flat is around 7 μm.

关键词： grain-size distributions suspended sediment resuspension settling Jiangsu coast