Influence de la granulométrie des particules sur la mesure par turbidimétrie des flux de matières en suspension dans les cours d’eau

Thollet, Fabien; Coz, Jérôme Le; Antoine, Gérald; François, Patrice; Saguintaah, L.; Launay, M.; Camenen, B.

doi:10.1051/lhb/2013033

Cited by 12 publications

(10 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…One of its main advantages is that it allows values to be obtained at high frequency with portable probes. However, this procedure requires calibration to account for particle size, nature, and color of suspended sediment (Ludwig & Hanes, 1990;Butt, Miles, Ganderton, & Russell, 2002;Minella, Merten, Reichert, & Clarke, 2008; Thollet et al, 2013). For example, the assumption of a single representative diameter is not appropriate and can lead to great uncertainty in the calculation of [C].…”

Section: Determination Of Suspended Sediment Concentration Profile mentioning

confidence: 99%

Measuring and modeling vertical gradients in suspended sediments in the Solimões/Amazon River

Armijos

Crave

Espinoza

et al. 2016

Hydrological Processes

View full text Add to dashboard Cite

International audienceAccurately measuring sediment flux in large rivers remains a challenge due to the spatial and temporal cross-sectional variability of suspended sediment concentrations in conjunction with sampling procedures that fail to accurately quantify these differences. This study presents a field campaign methodology that can be used to improve the measurement of suspended sediment concentrations in the Amazon River or similarly large rivers. The turbidity signal and Rouse model are together used in this study to define the spatial distribution of suspended sediment concentrations in a river cross-section, taking into account the different size fractions of the sediment. With this methodology, suspended sediment fluxes corresponding to each sediment class are defined with less uncertainty than with manual samples. This paper presents an application of this methodology during a field campaign at different gauging stations along a 3,000-km stretch of the Solimões/Amazon River during low water and flood periods. Vertical concentration profiles and Rouse model applications for distinctive sediment sizes are explored to determine concentration gradients throughout a cross-section of the river. The results show that coupling both turbidity technology and the Rouse model may improve our understanding of the spatial distribution of different sediments fractions sizes in the Solimões/Amazon River. These data are very useful in defining a pertinent monitoring strategy for suspended sediment concentrations in the challenging context of large rivers

show abstract

Section: Determination Of Suspended Sediment Concentration Profile mentioning

confidence: 99%

Measuring and modeling vertical gradients in suspended sediments in the Solimões/Amazon River

Armijos

Crave

Espinoza

et al. 2016

Hydrological Processes

View full text Add to dashboard Cite

show abstract

“…The Arc River drains mountainous watersheds in the French Alps and has a watershed area of 1500 km 2 with a mean annual flow of 16 m 3 s −1 at the Pontamafrey hydrological station (Thollet et al 2013). This is an alpine basin with high discharge during spring melt and low discharge during the fall period.…”

Section: Natural River Sedimentsmentioning

confidence: 99%

“…This is an alpine basin with high discharge during spring melt and low discharge during the fall period. The discharge variability is mitigated as the hydrology is strongly affected by hydropower management (Thollet et al 2013). The Arc River sediments are characterized by a high content of small minerals derived from the erosion of a black marls geologic layer (Thollet et al 2013;Antoine 2013) with 31 % sand, 64 % silt, and 5 % clay and an organic content of 1.7 %.…”

Section: Natural River Sedimentsmentioning

confidence: 99%

“…The discharge variability is mitigated as the hydrology is strongly affected by hydropower management (Thollet et al 2013). The Arc River sediments are characterized by a high content of small minerals derived from the erosion of a black marls geologic layer (Thollet et al 2013;Antoine 2013) with 31 % sand, 64 % silt, and 5 % clay and an organic content of 1.7 %. On an annual basis (June), the deposited sediments within the reservoirs on the Arc River are hydraulically flushed (BThe Arc Flush^) to increase hydroelectric potential and flood control (SSC often >10 g l −1 ) (Antoine 2013).…”

Section: Natural River Sedimentsmentioning

confidence: 99%

“…Arc River suspended sediment was collected from midchannel with a 10-l container during the 2012 Arc Flush (Camenen et al 2008;Thollet et al 2013). OSC measurements corresponded to a maximum SSC of 45 g l −1 (observed at Sainte-Marie-de-Cuines, 2 km downstream of the Pontamaffrey gauging station) during the flush.…”

Section: Sediment Sampling and Processingmentioning

confidence: 99%

See 2 more Smart Citations

Using an optical settling column to assess suspension characteristics within the free, flocculation, and hindered settling regimes

et al. 2015

View full text Add to dashboard Cite

Purpose Instruments able to measure the settling velocity distribution (SVD) and investigate the flocculation behavior of suspensions for a wide range of concentrations and settling regimes are required to understand and model sediment transport in headwater catchments. Such knowledge will improve our water resource management capabilities. Materials and methods An optical settling column, equipped with a vertical array of optical sensors, was used to provide light transmission through a suspension during quiescent settling. A new method to determine the settling velocity and the propensity of suspensions to flocculate is proposed. Its reliability was evaluated based on settling tests for (1) noncohesive sediments, (2) cohesive sediments at medium (~1 g l −1 ) concentration in a natural and deflocculated state, and (3) a cohesive sediment at a very high concentration (~10 g l −1 ). This choice of sediments and concentrations allowed for the assessment of free, flocculated, and hindered settling regimes. Results and discussion The proposed data processing method provides measurements for a range of test conditions. The result showed that different populations of particles with different settling behaviors can be identified within the suspensions. In the case of noncohesive sediments, the proposed method provided SVD similar to those obtained with reference methods. The propensity to flocculate was zero as expected for inert material. The natural cohesive sediment at medium concentration exhibited a large range of SVD (10 −2 -10 −5 m s −1 ) and high propensity to flocculate. These were both reduced with the addition of a deflocculant. Identified particle behaviors were consistent with independent measurement of size distribution, microscopic, and erosion properties. In the hindered regime, a narrow SVD corresponded to the hindered front settling velocity (~10 −4 m s −1 ). Conclusions An optical settling column was able to provide reliable SVD and an evaluation of the propensity of particles to flocculate. The settling column was able to detect variations of the settling velocities with settled depth, thus highlighting that settling columns with a single measurement point may provide erroneous results by not accounting for the full spectrum of settling depth.

show abstract

Spatial and temporal dynamics of suspended sediment fluxes in an alpine river: the Arc and Isère rivers, France

Camenen¹,

Archambault²,

Thollet³

et al. 2019

Preprint

View full text Add to dashboard Cite

Influence de la granulométrie des particules sur la mesure par turbidimétrie des flux de matières en suspension dans les cours d’eau

Cited by 12 publications

References 3 publications

Measuring and modeling vertical gradients in suspended sediments in the Solimões/Amazon River

Measuring and modeling vertical gradients in suspended sediments in the Solimões/Amazon River

Using an optical settling column to assess suspension characteristics within the free, flocculation, and hindered settling regimes

Spatial and temporal dynamics of suspended sediment fluxes in an alpine river: the Arc and Isère rivers, France

Contact Info

Product

Resources

About