Effects of suspended sediment concentration and grain size on three optical turbidity sensors

2013 ◽  
Vol 14 (7) ◽  
pp. 1235-1241 ◽  
Author(s):  
Gustavo Henrique Merten ◽  
Paul D. Capel ◽  
Jean P. G. Minella
Keyword(s):  
Grain Size ◽  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Optical Turbidity

scholarly journals Sediment transport modelling in riverine environments: on the importance of grain-size distribution, sediment density and boundary conditions

2018 ◽  
Author(s):  
Jérémy Lepesqueur ◽  
Renaud Hostache ◽  
Núria Martínez-Carreras ◽  
Emmanuelle Montargès-Pelletier ◽  
Christophe Hissler
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Size Distribution ◽  
Suspended Sediment ◽  
Grain Size Distribution ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Small Scale ◽  
Sediment Grain Size ◽  
Model Based

Abstract. Hydromorphodynamic models are powerful tools to predict the potential mobilization and transport of sediment in river ecosystems. Recent studies even showed that they are able to satisfyingly predict suspended sediment matter concentration in small river systems. However, modelling exercises often neglect suspended sediment properties (e.g. particle site distribution and density), even though such properties are known to directly control the sediment particle dynamics in the water column during rising and flood events. This study has two objectives. On the one hand, it aims at further developing an existing hydromorphodynamic model based on the dynamic coupling of TELEMAC-3D (v7p1) and SISYPHE (v7p1) in order to enable an enhanced parameterisation of the sediment grain size distribution with distributed sediment density. On the other hand, it aims at evaluating and discussing the added-value of the new development for improving sediment transport and riverbed evolution predictions. To this end, we evaluate the sensitivity of the model to sediment grain size distribution, sediment density and suspended sediment concentration at the upstream boundary condition. As a test case, the model is used to simulate a flood event in a small scale river, the Orne River in North-eastern France. The results show substantial discrepancies in bathymetry evolution depending on the model setup. Moreover, the sediment model based on an enhanced sediment grain size distribution (10 classes) and with distributed sediment density outperforms the model with only two sediment grain size classes in terms of simulated suspended sediment concentration.

scholarly journals Sediment dynamics across gravel-sand transitions: Implications for river stability and floodplain recycling

Geology ◽  
2020 ◽  
Vol 48 (5) ◽  
pp. 468-472 ◽  
Author(s):  
Elizabeth H. Dingle ◽  
Hugh D. Sinclair ◽  
Jeremy G. Venditti ◽  
Mikaël Attal ◽  
Tim C. Kinnaird ◽  
...  
Keyword(s):  
Grain Size ◽  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Sediment Flux ◽  
Sand Transport ◽  
Channel Stability ◽  
Gravel Bed ◽  
Continental Scale ◽  
Material Load

Abstract The gravel-sand transition (GST) is commonly observed along rivers. It is characterized by an abrupt reduction in median grain size, from gravel- to sand-size sediment, and by a shift in sand transport mode from wash load–dominated to suspended bed material load. We documented changes in channel stability, suspended sediment concentration, flux, and grain size across the GST of the Karnali River, Nepal. Upstream of the GST, gravel-bed channels are stable over hundred- to thousand-year time scales. Downstream, floodplain sediment is reworked by lateral bank erosion, particularly during monsoon discharges. Suspended sediment concentration, grain size, and flux reveal counterintuitive increases downstream of the GST. The results demonstrate a dramatic change in channel dynamics across the GST, from relatively fixed, steep gravel-bed rivers with infrequent avulsion to lower-gradient, relatively mobile sand-bed channels. The increase in sediment concentration and near-bed suspended grain size may be caused by enhanced channel mobility, which facilitates exchange between bed and bank material. These results bring new constraints on channel stability at mountain fronts and indicate that temporally and spatially limited sediment flux measurements downstream of GSTs are more indicative of flow stage and floodplain recycling than of continental-scale sediment flux and denudation rate estimates.

Influence of hydrological conditions and peat extraction operations on suspended sediment concentration and deposition in the East Branch Portage River, New Brunswick (Canada)

2013 ◽  
Vol 48 (4) ◽  
pp. 305-320 ◽  
Author(s):  
M. A. Es-Salhi ◽  
M. Clément ◽  
A. St-Hilaire ◽  
D. Caissie ◽  
S. C. Courtenay
Keyword(s):  
Grain Size ◽  
New Brunswick ◽  
Size Distribution ◽  
Suspended Sediment ◽  
Grain Size Distribution ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Organic Content ◽  
Sediment Type ◽  
Peat Extraction

Peat extraction activities often generate sediments that can be transported into streams and rivers. These sediments have sometimes been shown to negatively affect the natural environment. This study investigated the effects of peat production on the East Branch Portage River, New Brunswick (NB), Canada. Relationships between discharge, precipitation and suspended sediment concentration (SSC) were analysed. The effect of sedimentation pond maintenance activities on SSC was also studied. Finally, the grain size distribution and organic content of deposited sediments were quantified at five sites downstream of the pond. Three water quality stations were monitored during the ice-free period in 2007 and 2008. Results showed that SSC was not significantly correlated with precipitation and weakly correlated with discharge, although some of the high SSC events were triggered by high discharge and precipitation. Pond maintenance alone failed to ensure optimal sedimentation pond efficiency. In 2008, SSC increased a few days after pond maintenance. The NB SSC 25 mg/L guideline was exceeded at all stations in both years. Analysis of variance results showed that there were significant differences in the grain size distribution of deposited sediments at the five sampled sites. Sand was the prevailing sediment type deposited downstream of the sedimentation pond.

scholarly journals The Interplay between Flow Field, Suspended Sediment Concentration, and Net Deposition in a Channel with Flexible Bank Vegetation

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2250 ◽  
Author(s):  
Walter Box ◽  
Kaisa Västilä ◽  
Juha Järvelä
Keyword(s):  
Flow Field ◽  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Main Channel ◽  
Future Research ◽  
Flume Experiments ◽  
Realistic Description ◽  
Optical Turbidity

This paper investigates the interplay between the flow, suspended sediment concentration (SSC), and net deposition at the lateral interface between a main channel and riverbank/floodplain vegetation consisting of emergent flexible woody plants with understory grasses. In a new set of flume experiments, data were collected concurrently on the flow field, SSC, and net deposition using acoustic Doppler velocimeters, optical turbidity sensors, and weight-based sampling. Vegetation largely affected the vertical SSC distributions, both within and near the vegetated areas. The seasonal variation of vegetation properties was important, as the foliage strongly increased lateral mixing of suspended sediments between the unvegetated and vegetated parts of the channel. Foliage increased the reach-scale net deposition and enhanced deposition in the understory grasses at the main channel–vegetation interface. To estimate the seasonal differences caused by foliation, we introduced a new drag ratio approach for describing the SSC difference between the vegetated and unvegetated channel parts. Findings in this study suggest that future research and engineering applications will benefit from a more realistic description of natural plant features, including the reconfiguration of plants and drag by the foliage, to complement and replace existing rigid cylinder approaches.

scholarly journals Sediment transport modelling in riverine environments: on the importance of grain-size distribution, sediment density, and suspended sediment concentrations at the upstream boundary

2019 ◽  
Vol 23 (9) ◽  
pp. 3901-3915 ◽  
Author(s):  
Jérémy Lepesqueur ◽  
Renaud Hostache ◽  
Núria Martínez-Carreras ◽  
Emmanuelle Montargès-Pelletier ◽  
Christophe Hissler
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Size Distribution ◽  
Suspended Sediment ◽  
Grain Size Distribution ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Sediment Grain Size ◽  
Model Based ◽  
Model Set

Abstract. Hydromorphodynamic models are powerful tools for predicting the potential mobilization and transport of sediment in river ecosystems. Recent studies have shown that they are able to predict suspended sediment matter concentration in small river systems satisfactorily. However, hydro-sedimentary modelling exercises often neglect suspended sediment properties (e.g. sediment densities and grain-size distribution), which are known to directly control sediment dynamics in the water column during flood events. The main objective of this study is to assess whether a better representation of such properties leads to an improved performance in the model. The modelling approach utilizes a fully coupled hydromorphodynamic model based on TELEMAC-3D (v7p1) and an enhanced version of the sediment transport module SISYPHE (based on v7p1), which allows for a refined sediment representation (i.e. 10-class sediment mixtures instead of 2-class mixtures and distributed sediment density instead of uniform). The proposed developments of the SISYPHE model enable us to evaluate and discuss the added value of sediment representation refinement for improving sediment transport and riverbed evolution predictions. To this end, we used several model set-ups to evaluate the influence of sediment grain-size distribution, sediment density, and suspended sediment concentration at the upstream boundary on model predictions. As a test case, we simulated a flood event in a small-scale river, the Orne river in north-eastern France. Depending on the model set-up, the results show substantial discrepancies in terms of simulated bathymetry evolutions. Moreover, the model based on an enhanced configuration of the sediment grain-size distribution (10 classes of particle sizes) and with distinct densities per class outperforms the standard SISYPHE configuration, with only two sediment grain-size classes, in terms of simulated suspended sediment concentration.

scholarly journals Suspended sediment yield characteristics variability in rivers of Kamchatka krai

2019 ◽  
pp. 52-61
Author(s):  
L. V. Kuksina
Keyword(s):  
Grain Size ◽  
Suspended Sediment ◽  
Sediment Yield ◽  
Suspended Sediment Concentration ◽  
Volcanic Eruptions ◽  
Sediment Concentration ◽  
Spatiotemporal Variability ◽  
Water Runoff ◽  
Suspended Sediment Yield ◽  
Subsequent Decrease

The regularities of spatiotemporal variability of suspended sediment yield characteristics were studied. Based on the analysis of difference-integral yield curves, it was found that most of the rivers in Kamchatka krai are characterized by the presence of two relatively long trends in the suspended sediment yield variability: an increase until the end of the 1970s–early 1980s, and its subsequent decrease. This regularity disturbs in rivers under the influence of volcanic eruptions, where the most significant increasing of sediment yield is observed after major eruptions. Existent maps of mean annual suspended sediment concentration and mean annual specific suspended sediment yield were significantly specified (18 instead 4 and 13 instead two zones were marked respectively). The map of grain-size distribution of suspended sediment was compiled (three zones was marked in region under study). Maximum values of mean annual specific suspended sediment yield (more than 500 t km-2 yr-1), suspended sediment concentration (more than 1000 g m-3) and grain-size of sediments are observed in water runoff of volcanic areas. Minimum values of suspended sediment concentration, specific suspended sediment yield, as well as grain-size of sediments characterized the mainland part of the krai.

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