scholarly journals Response of suspended sediment concentration to tidal dynamics at a site inside the mouth of an inlet: Jiaozhou Bay (China)

2004 ◽  
Vol 8 (2) ◽  
pp. 170-182 ◽  
Author(s):  
S. L. Yang ◽  
J. Zhang ◽  
J. Zhu
Keyword(s):  
Suspended Sediment ◽  
Current Velocity ◽  
Jiaozhou Bay ◽  
Time Lag ◽  
Sediment Concentration ◽  
Tidal Range ◽  
Suspended Sediment Transport ◽  
Fair Weather ◽  
Tidal Dynamics ◽  
A Site

Abstract. Observations of fair weather currents and suspended sediment concentrations (SSC) were made using an acoustic Doppler current profiler and two YSI turbidity sensors over a neap to spring time cycle at a site near the inner mouth of a semi-enclosed mesotidal-macrotidal embayment (Jiaozhou Bay) to examine the influence of tidal dynamics on concentration and transport of suspended sediment. During the investigation, SSC varied from about 3 to 16 mg L–1 at the surface and about 6 to 40 mg L–1 close to the bed, while the current velocity reached 79 cm s–1 at the surface and 61 cm s–1 near the bed. SSC was tidally cyclic. The near-bed instantaneous SSC was closely related to current velocity with almost no time lag, indicating that the variability of SSC was governed by current-induced settling/resuspension. At the surface, however, instantaneous SSC was poorly related to instantaneous current velocity because the peak SSC tended to occur around ebb slack water. This suggests that the surface SSC was controlled by horizontal advection from landward higher concentration areas. Both at the surface and near the bed, on the other hand, tidally-averaged SSC was well correlated to tidal range and current speed. Current velocity and SSC were flood-dominated for all the tides investigated, which resulted in significant landward residual suspended sediment transport at the study site. The observed flood dominance was mainly attributed to the location of the study site on the landward side of the bay’s inlet where flow separation is favoured during flood tide. It was concluded that tides are the dominant hydrodynamic component controlling the variability of SSC during fair weather at the study area. Keywords: sediment, concentration, suspension, advection, currents, shoalling effect, Jiaozhou Bay, China

scholarly journals Hydrodynamics and suspended sediment transport in the Camboriú estuary - Brazil: pre jetty conditions

2009 ◽  
Vol 57 (2) ◽  
pp. 123-135 ◽  
Author(s):  
Eduardo Siegle ◽  
Carlos A. F. Schettini ◽  
Antonio H. F. Klein ◽  
Elírio E. Toldo Jr.
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Spring Tide ◽  
Sediment Concentration ◽  
Transport Processes ◽  
Stokes Drift ◽  
Tidal Range ◽  
Background Information ◽  
Suspended Sediment Transport ◽  
Estuarine Hydrodynamics

Estuarine hydrodynamics is a key factor in the definition of the filtering capacity of an estuary and results from the interaction of the processes that control the inlet morphodynamics and those that are acting in the mixing of the water in the estuary. The hydrodynamics and suspended sediment transport in the Camboriú estuary were assessed by two field campaigns conducted in 1998 that covered both neap and spring tide conditions. The period measured represents the estuarine hydrodynamics and sediment transport prior to the construction of the jetty in 2003 and provides important background information for the Camboriú estuary. Each field campaign covered two complete tidal cycles with hourly measurements of currents, salinity, suspended sediment concentration and water level. Results show that the Camboriú estuary is partially mixed with the vertical structure varying as a function of the tidal range and tidal phase. The dynamic estuarine structure can be balanced between the stabilizing effects generated by the vertical density gradient, which produces buoyancy and stratification flows, and the turbulent effects generated by the vertical velocity gradient that generates vertical mixing. The main sediment source for the water column are the bottom sediments, periodically resuspended by the tidal currents. The advective salt and suspended sediment transport was different between neap and spring tides, being more complex at spring tide. The river discharge term was important under both tidal conditions. The tidal correlation term was also important, being dominant in the suspended sediment transport during the spring tide. The gravitational circulation and Stokes drift played a secondary role in the estuarine transport processes.

Variation behavior of tidal dynamics in the Yangtze Estuary: implying the amplification of hydrodynamics and sediment dynamics by the human intervention

2020 ◽  
Author(s):  
Heqin Cheng ◽  
Wei Chen ◽  
Lizhi Teng ◽  
Xiaoting Yuan
Keyword(s):  
Seasonal Variation ◽  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Yangtze Estuary ◽  
Sediment Dynamics ◽  
Tidal Range ◽  
Tidal Dynamics ◽  
The Yangtze Estuary ◽  
Tidal Characteristic

<p><span><span>During the last decades, many estuarine systems in Europe (e.g. the Elbe, Ems, Loire) have shown increases in tidal range and in turbidity, which are linked to local human activity (i.e., deepening). Compared to these European estuaries, the Yangtze Estuary is much larger in scales, experiences much stronger river discharge, and it is subject to a strong seasonal variation in freshwater and sediment supply from the drainage area. Moreover, the Yangtze estuary is a complex network with several branches, connecting channels. The changes in the flow and sediment dynamics in the estuary may result from both local and nonlocal human activities. Despite the intense research efforts over the past two decades, it is still unclear which impact (local or nonlocal) is responsible for the changing flow and sediment characteristics in the estuary. Deep investigation of tidal characteristic quantities such as extreme tidal level, tidal range, amplitude of tidal constituents, tidal characteristic coefficient and suspended sediment concentration is performed in a systematic manner. It is accomplished using the extreme value analysis, the wavelet analysis and harmonic analysis of water level at 11 hydrography stations along the tidal river channel (Datong-Nanjing reach) and estuarine section (downstream the Xuliujing) during 2008-2016. Similar data analysis is also performed for the last four decades of 20th century and results are compared with the analysis of the recent measurements. The driving forces of the significant changes in tidal characteristic quantities and suspended sediment concentration are discussed. Results show that the tidal dynamics in the Yangtze estuary has been enhanced. Its seasonal variation is attributed to the adjustment of runoff distribution, which is mainly caused by the operation of Three Gorges Dam. In short-term, local changes of flow/sediment dynamics, terrain changes play a major role. In the long term (on the 40-year time scale), the effect of sea level rise on the increasing M2 constituent is obvious. This has mainly resulted from the enhancing anti-clockwise rotation of the synchronous tidal phase.</span></span></p><p> </p>

scholarly journals Comparative Assessment of Fluvial Suspended Sediment Concentration Analysis Methods

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 873 ◽  
Author(s):  
Flóra Pomázi ◽  
Sándor Baranya
Keyword(s):  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Acoustic Doppler Current Profiler ◽  
Sediment Concentration ◽  
Comparative Assessment ◽  
Danube River ◽  
Suspended Sediment Transport ◽  
Indirect Methods ◽  
Analysis Methods ◽  
Sediment Monitoring

The monitoring of fluvial suspended sediment transport plays an important role in the assessment of morphological processes, river habitats, or many social activities associated with river management. However, establishing and operating a well-functioning sediment monitoring system requires the involvement of advanced indirect methods. This study investigates the advantages and limitations of optical and acoustic devices, to quantify the uncertainties and provide a comprehensive comparative assessment of the investigated indirect methods. The novelty of this study, compared to previous ones, is that four different indirect techniques are parallel tested, i.e., the laser diffraction based LISST-Portable|XR, an infrared based optical instrument, the VELP TB1 turbidimeter, the acoustic based LISST-ABS (Acoustical Backscatter Sensor) sensor, and a 1200 kHz Teledyne RD Instruments Acoustic Doppler Current Profiler (ADCP). The calibration of all the indirect methods was performed based on more than 1000 samples taken from the Hungarian section of the Danube River within a wide suspended sediment concentration range. Implementing a comparative assessment of the different sediment analysis methods, a qualitative and quantitative characterisation of the applicability is provided. Furthermore, a proposal for an optimised sediment monitoring methodology is also suggested.

On the Suspended Sediment Concentration Profile

2012 ◽  
Vol 212-213 ◽  
pp. 20-24 ◽  
Author(s):  
Chen Cheng ◽  
Zhi Yao Song ◽  
Yi Gang Wang ◽  
Jin Shan Zhang
Keyword(s):  
Boundary Condition ◽  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Order Approximation ◽  
Sediment Concentration ◽  
Suspended Sediment Transport ◽  
Surface Boundary ◽  
Sediment Diffusion Coefficient ◽  
Surface Boundary Condition ◽  
First Order Approximation

After analyzing the surface-boundary condition of suspended sediment concentration (SSC), Cheng et al.[7] further improved the sediment diffusion coefficient which was proposed by Bose and Dey[6]. Then an improved Rouse law (IRL) was developed. This equation, which has a similar form as Rouse law, not only overcomes the zero concentration at the free surface, but also behaves generally better than Rouse law and van Rijn equation over the whole water depth in the verification analysis. In this paper, the surface-boundary condition of SSC is further analyzed. It is elucidated that IRL satisfies the surface-boundary condition more reasonably than Rouse law. In addition, a first-order approximation of IRL is developed. From this approximation, we can easily get the explicit expression of the depth-averaged SSC without any implicit integrals to be solved numerically or by the help of a chart. This is very useful in the further study of non-equilibrium suspended sediment transport (SST).

Introducing surface sampling threshold factor for suspended sediment transport: model development using Sri Lankan tropical highland river basins

2013 ◽  
Vol 46 (1) ◽  
pp. 136-155 ◽  
Author(s):  
Sandun Illangasinghe ◽  
Tilak Hewawasam
Keyword(s):  
Sri Lanka ◽  
Suspended Sediment ◽  
Transport Model ◽  
Low Cost ◽  
Model Development ◽  
Sediment Concentration ◽  
Generic Model ◽  
Suspended Sediment Transport ◽  
Surface Sampling ◽  
Threshold Factor

Estimation of suspended sediment concentration (SSC) in rivers is a prerequisite to address many issues related to hydrology. Therefore, we make an attempt in this study to introduce a low-cost technique to estimate the SSC. Both surface and depth-and-width-integrated water samples were collected and measured for SSC from eight tributaries in Sri Lanka over a complete hydrological year. A site-specific calibration curve was established between SSCs measured by two methods for each tributary where R2 varied from 0.72 to 0.99. The same relationship is developed in general for all tributaries studied in the hilly terrain of Sri Lanka. This generic model exhibits a strong correlation (R2 = 0.91), which will be useful to calculate an accurate SSC from a simply measured surface SSC. To select the appropriate gauging method, be it surface or depth-and-width-integrated sampling, a new concept of surface sampling threshold factor (SSTF) is introduced. The preliminarily analysis on SSTF using available data for the studied catchments reveals that surface sampling is only adequate for estimating a representative SSC if SSTF varies from 35 to 45. When SSTF deviates from this range, the SSC measured by surface sampling needs to be adjusted by depth-and-width-integrated sampling.

Landscape and river self-organization limit the flux of fine particles

2020 ◽  
Author(s):  
Colin Phillips ◽  
Carlos Rogéliz ◽  
Daniel Horton ◽  
Jonathan Higgins ◽  
Aaron Packman
Keyword(s):  
Suspended Sediment ◽  
Fine Particle ◽  
River Flow ◽  
Fine Particles ◽  
Strong Support ◽  
Sediment Concentration ◽  
Sediment Flux ◽  
Suspended Sediment Transport ◽  
Erosion Rates ◽  
Suspended Sediment Flux

<p>Fine particles in rivers comprise a substantial fraction (>50%) of the mass leaving a landscape, while at shorter timescales they represent significant carriers of nutrients and contaminants with the potential to both degrade and enhance aquatic habitats. Predicting fine particle dynamics within rivers remains challenging due to a complex relationship between sediment and water availability from the landscape. This inherent complexity results in watershed-specific understandings of suspended sediment dynamics, typically parameterized as empirical functions of catchment land use, geology, and climate. However, observations of significant fine particle storage within river corridors may indicate that the flux of suspended sediment depends on reach-scale hydraulics. To better understand these dynamics, we synthesized over 40 years of suspended sediment concentration (SSC), hydraulic geometry, river flow, and grainsize data collected by the US Geological Survey from hundreds of rivers spanning a large variety of environments across the continental United States. This data synthesis reveals a strong nonlinear trend between reach-scale hydraulics and the suspended sediment flux, with a secondary dependence on particle properties. The multi-site synthesis reveals that by normalizing the suspended sediment flux by the bankfull shear stress and flux results in a collapse of the observed data onto a single function that describes a self-organizing structure for suspended sediment transport in watersheds. This general relationship indicates strong support for the role of autogenic processes in setting the flux of fine particles and erosion rates of watersheds.</p>

Study on the Tidal Current and Suspended Sediment Transport in Taizhou Bay

2012 ◽  
Vol 212-213 ◽  
pp. 55-58
Author(s):  
Jie He ◽  
Xin Sheng Zhao ◽  
Yu Fan Zhu
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Suspended Sediment ◽  
Tidal Current ◽  
Sediment Concentration ◽  
Suspended Sediment Transport ◽  
Sediment Source ◽  
Sea Floor ◽  
Hydrologic Data ◽  
The Way

Taizhou Bay is an estuary with high tidel range, middle tidal current and low sediment concentration. For the sea floor is very dense, it is stable in the usual water regimen. The numerical model is introduced to simulate the suspended sediment transport in Taizhou Bay. And the recent hydrologic data and the seabed change have been validated by the numerical model. The movement of tidal current and sediment in Dagagn Bay are simulated, and the sediment siltation in port designed is calculated by the model. The results show that the sediment source is from the shoal produced by the ebb current, and the sediment silting is decreased two-thirds by the cofferdam back of the bay, because the way of the suspended sediment is stopped by the cofferdam from the shoal to the harbor.

scholarly journals An application of adaptive cluster sampling for estimating total suspended sediment load

2009 ◽  
Vol 41 (1) ◽  
pp. 63-73 ◽  
Author(s):  
M. Arabkhedri ◽  
F. S. Lai ◽  
I. Noor-Akma ◽  
M. K. Mohamad-Roslan
Keyword(s):  
Suspended Sediment ◽  
Sediment Concentration ◽  
Cluster Sampling ◽  
Suspended Sediment Transport ◽  
Adaptive Cluster Sampling ◽  
Total Load ◽  
Sediment Rating Curve ◽  
Sediment Loads ◽  
Daily Concentration ◽  
Rating Curves

Suspended sediment transport in river for a particular period is a timescale finite population. This population shows natural aggregation tendencies in sediment concentration particularly during floods. Adaptive cluster sampling (ACS) can be potentially conducted for sampling from this rare clustered population and estimating total load. To illustrate the performance of ACS in sediment estimation, a comparative study was carried out in the Gorgan-Rood River, Iran, with around a 5 year daily concentration record. The total sediment loads estimated by ACS were statistically compared to the observed load, estimations of selection at list time (SALT) and conventional sediment rating curve with and without correction factors. The results suggest that none of the sediment rating curves produced accurate estimates, while both ACS and SALT showed satisfactory results at a semi-weekly sampling frequency. The best estimation obtained by the rating curves did not show a percent error better than −40%; however, ACS and SALT underestimated the load at less than 5%. The results of this study suggest ACS could improve river monitoring programs.

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