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Effect of Water and sediment Regulation on Lower Yellow River

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Transactions of Tianjin University 2009年第2期15卷 113-120页

作者：徐国宾司春棣 School of Civil Engineering Tianjin University School of Mechanical Engineering Shijiazhuang Railway Institute

According to the results of the water and sediment regulations of the Yellow River in year 2002—2007,the effect of erosion and deposition on the lower reaches,the amount and distribution of erosion and deposition in the river mouth area,the adjustment of river regime,the effect of river regulation projects and changes of flowing capacity of the channel are *** is revealed that the water and sediment regulation is efficient to reduce deposition and improve the flowing capacity and the conditions of sediment transport.

关键词： Yellow River water and sediment regulation river control sediment transport

Assessing suspended sediment fluxes with acoustic Doppler current profilers:case study from large rivers in Russia

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Big Earth Data 2022年第4期6卷 504-526页

作者： Sergey Chalov Vsevolod Moreido Victor Ivanov Aleksandra Chalova Faculty of Geography Lomonosov Moscow State UniversityMoscowRussia Institute of Physics Kazan Federal UniversityKazanRussia Flood Hydrology Lab Water Problems Institute of Russian Academy of SciencesMoscowRussia

Surrogate measures are becoming increasingly used to measure suspended sediment flux,but only few particular computer techniques of data processing are recently *** study demonstrates capabilities of acoustic Doppler current profilers(ADCPs)to infer information regarding suspended-sand concentrations in river systems and calculate suspended sediment flux via big data analytics which includes process of analyzing and data mining of measurements based on ADCP signal backscatter intensity *** present here specific codes done by R language using RStudio software with open-source tidyverse and plotly packages aimed to generate tables containing data of suspended load for cells,verticals and whole cross-section based on backscattering values from 600 kH Teledyne RDInstruments RioGrande WorkHorse ADCP unit,as well perform estimates of morphometric,suspended sediment concentration(SSC)and velocity characteristics of the *** developed tools enabled to process large data array consisting of over 56,526,480 geo-referenced values of river depth,streamflow velocity,and backscatter intensity for each river cross-section measured at six case study sites in Russia.

关键词： Big data ADCP backscatter intensity sediment transport

Approximate velocity formula over mobile sediment bed induced by velocity-skewed waves and current

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International Journal of sediment Research 2022年第3期37卷 317-327页

作者： Xin Chen Minghong Chen Jingkai Wu Haifei Liu Chen Yang Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural University State Key Laboratory of Hydroscience and Engineering Department of Hydraulic Engineering Tsinghua University China Huadian Corporation School of Environment Beijing Normal University School of Water Conservancy North China University of Water Resources and Electric Power

A velocity formula is proposed for flow over a mobile sediment bed induced by velocity-skewed waves and current. The formula is obtained by a separation of waves and current velocities and requires seven free variables related to free stream velocity and sediment characteristics. The formula includes two parts:(1) a wave part consisting of the free stream velocity and defect function, which considers phase lead, wave boundary layer thickness, and mobile bed level, and(2) a current part, which changes the wave part through the boundary layer thickness and mobile bed level, influenced by wave eddy *** wave part is superior to the current part such that the boundary layer characteristics are mainly determined by the waves. The wave process is divided into four quarter stages to model the asymmetries of parameters in velocity and acceleration. Under velocity-skewed waves and current conditions, velocity asymmetry and residual velocity are accounted for in the formula, especially the offshore residual velocity with a large phase lag and mobile bed effect with a small phase lag. Phase lead is shown to be nonconstant in velocity-skewed oscillatory sheet flow and corresponds to an extra offshore residual velocity.

关键词： Analytical approximate velocity Mobile sediment bed sediment transport Velocity asymmetry Wave and current

Temporal variations of sediment and morphological characteristics at a large confluence accounting for the effects of floodplain submergence

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International Journal of sediment Research 2022年第5期37卷 619-638页

作者： Kun Li Hongwu Tang Saiyu Yuan Lei Xu Yang Xiao Carlo Gualtieri State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Yangtze Institute for Conservation and Development Department of Structures for Engineering and Architecture University of Napoli Federico Ⅱ

The large confluence between the Yangtze River and the outflow channel of Poyang Lake is receiving attention due to its importance in flood control and ecological protection in the Yangtze River *** is a large floodplain along the outflow channel of Poyang Lake, which is submerged during high flow and dry during low flow. The effects of the submergence of this floodplain on sediment and morphological characteristics at this large confluence have not been known. Hence, a field investigation was done in March 2019(relatively high flow, Survey 3) to complement the previous field studies done in August(high flow, Survey 1) and December 2018(low flow, Survey 2) to identify the temporal variations of sediment and morphological characteristics considering the submergence of this large floodplain. The predominant sediment transport modes were wash load for Poyang Lake and confluence particles and mixed bedload/suspended load for the Yangtze River particles. The sediment transport processes were largely affected by both the secondary flows and the water density contrast between the tributaries with a lock-exchange sediment rich, denser flow moving across the inclined mixing interface in Surveys 1 and 2. The sediment flux across the mixing interface was weakened in Survey 3 when the density contrast was very small. The stagnation zone near the confluence apex had a low sediment concentration and played a role in preventing the sediment flux exchange between the two flows, and its size, and, thus, its importance as a barrier to sediment mixing were related to the submergence of the floodplain. The bed morphology with the local scour holes at the confluence was largely affected by the large-size helical cells, and this kind of effect was weakened as the secondary flows got restricted in Survey 3. The current results expand the database and knowledge on the sediment transport and morphological features of large river confluences.

关键词： River confluence Yangtze river Poyang lake Compound channel sediment transport Morphodynamics

NUMERICAL COMPUTATION OF VERTICAL TWO-DIMENSIONALNON-EQUILIBRIUM sediment MOVEMENT

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International Journal of sediment Research 1999年第2期14卷 251-257页

作者： HUANG Yongiian (1 China Institute of Water Resources and Hydropower Research, P.O.Box 366,Beijing 100044.)

Non-equilibrium sediment transport is studied by using a numerical solution of vertical two dimensional diffusion equations. sediment concentration on the bed is determined as the boundary condition of diffusion equation based the sediment carrying capacity of local flow. The velocity field is solved and then the two dimensional diffusion equations in each section along the flow direction are solved. The vertical distribution of sediment concentration is determined and then the quantities of erosion or siltation are obtained along the cross sections. The usage of this numerical computation method is further explained in unsteady flow examples.

关键词： Non-equilibrium sediment transport sediment concentration Numerical model Velocity field

FINE sediment OF THE UPPER MISSISSIPPI ANDILLINOIS RIVERS AND THE DISASTROUS CONSEQUENCES

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International Journal of sediment Research 1999年第2期14卷 171-178页

作者： TaWei SOONG1 (l Watershed Science Section, Illinois State Water Survey. Department of natural Resources. 2204 Griffith Drive. Champaign, IL 61820)

Increased sediment loads and sedimentation rates in rivers and streams have produced major disturbances to the society. However, while discussing f sediment transport and sediment induced problems focuses have often been given to those related to coarse sediments; tine sediment induces problems have been primarily investigated in bays and estuaries. In the case of Upper Mississippi River System (UMRS), increased turbidity and suspended sediment solids in the water column; heavy sediment deposition in channel boarders, backwater lakes, and side channels have shown to be problematic. Besides their impacts on human activities, fine sediments have also adversely affected water quality and flora and fauna of the river System. The total areas that affected, their accessibility, the amount, not to mention the contaminants involved, are complex challenges to the e1Yorts to restore the rivers’ functions. Many resource managers consider heavy sediment deposition in backwaters and side channels to be one of the most severe environmental problems on the UMRS. Large rivers are priceless resources and sedimentation plays a vital role in their sustainability. The example and experience learned from the UMRS can provide valuable information for management practices of other river basins.

关键词： Mississippi River Fine sediment sediment transport Water quality

Measuring and modeling suspended sediment concentration profiles in the surf zone

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Journal of Palaeogeography 2012年第2期1卷 172-192页

作者： Ping Wang Department of Geology, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620, USA Department of Geology University of South Florida

Time-averaged suspended sediment concentration profiles across the surf zone were measured in a large-scale three-dimensional movable bed laboratory facility (LSTF:Large-scale sediment transport Facility). sediment suspension under two different types of breaking waves, spilling and plunging breakers, was investigated. The magnitudes and shapes of the concentration profiles varied substantially at different locations across the surf zone, reflecting the different intensities of breaking-induced turbulence. sediment sus- pension at the energetic plunging breaker-line was much more active, resulting in nearly homogeneous concentration profiles throughout most of the water column, as compared to the reminder of the surf zone and at the spilling breaker-line. Four suspended sediment concentration models were examined based on the LSTF data, including the mixing turbulence length approach, segment eddy viscosity model, breaking-induced wave-energy dissipation approach, and a combined breaking and turbulence length model developed by this study. Neglecting the breaking-induced turbulence and subsequent sediment mixing, suspended sediment concentration models failed to predict the across-shore variations of the sediment suspension, especially at the plunging breaker-line. Wave-energy dissipation rate provided an accurate method for estimating the intensity of turbulence generated by wave breaking. By incorporating the breaking-induced turbulence, the combined breaking and turbulence length model reproduced the across-shore variation of sediment suspension in the surf zone. The combined model reproduced the measured time-averaged suspended sediment concentration profiles reasonably well across the surf zone.

关键词： sediment transport suspended sediment transport wave breaking coastal morphodynamics coastal processes beach processes surf zone physical modeling

THE USE OF GRAIN SIZE TRENDS IN MARINE sediment DYNAMICS: A REVIEW

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Chinese Journal of Oceanology and Limnology 2001年第3期19卷 265-271页

作者： MichaelCollins 高抒 InstituteofOceanology ChineseAcademyofSciencesQingdao266071China SchoolofOceanandEarthScience theUniversitySouthamptonS0143ZHUK

Spatial changes in grain size parameters (i.e. grain size trends) contain information on sediment transport patterns. An analytical procedure has been proposed to transform the grain size trends into an image of trend vectors, which may represent net sediment transport pathways. A fundamental assumption for such an approach is that the frequency of occurrence of the trend adopted is much higher in the transport direction, than in any of other directions. Preliminary studies show agreement between this assumption and observations. However, further investigations into the physical processes and mechanisms for the formation of grain size trends are required to improve the technique, including flume experiments and numerical modeling. Moreover, attention should be paid to the trends associated with fine grained sediment, for the method of grain size trend analysis is so far designed for coarse grained material only. The processes of flocculation during settling and the wash load property must be considered. Appropriate interpretation of grain size data will improve our understanding of the physics of granular materials.

关键词： Grain size trend vectors sediment transport marine environment

Morphodynamic Characteristics and Medium-Term Simulation of the North-South Passage Under the Impact of the Yangtze Estuary Deepwater Navigation Channel Project

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China Ocean Engineering 2020年第2期34卷 198-209页

作者： JIAO Jian DOU Xi-ping GAO Xiang-yu DING Lei YANG Xiao-yu Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China

The morphological evolution characteristics of the North-South Passage area since the construction of the Yangtze Estuary Deepwater Navigation Channel Project(DNCP)are analyzed on the basis of the measured data.A twodimensional morphodynamics numerical model of the Yangtze Estuary is established to verify the morphological evolution of the North-South Passage under the influence of the DNCP and to predict the future evolution in the next 40 *** analysis shows that the North Passage has experienced rapid adjustment stages and adaptive stages after the construction of the *** erosion occurred along the main channel,and slow siltation could be observed in the area between the *** South Passage showed a state of upper section erosion and down section *** present,the whole South Passage is in a slight erosion *** to the numerical model,the eroding and silting speed of the North Passage will slow down in the *** present state that erosion occurs in the main channel and siltation occurs between the groins will *** South Passage will still maintain upper section erosion and down section deposition in the *** to the main channel erosion of the North Passage and siltation of the South Passage,the sediment division ratio of the North Passage will increase in the future but still be smaller than 50%.After morphological evolution of 40 years,the direction of residual sediment transport caused by M2 and M4 tidal components in the North Passage has not changed,but the transport rate will *** is considered that the morphological evolution of the North-South Passage could reach a relatively stable state after 40 years.

关键词： Yangtze Estuary numerical model morphology tidal current sediment transport deepwater navigation channel project(DNCP)