scholarly journals NUMERICAL MODELLING OF SUSPENDED SEDIMENT

1974 ◽  
Vol 1 (14) ◽  
pp. 65
Author(s):  
Brian A. O'Connor ◽  
Samir Zein
Keyword(s):  
Suspended Sediment ◽  
Eddy Diffusion ◽  
Suspended Sediment Transport ◽  
Physical Parameters ◽  
Advection Equation ◽  
Two Dimensional ◽  
Concentration Gradients ◽  
Vertical Diffusion ◽  
Fall Velocity ◽  
Time Step

The present paper describes the application of a two-dimensional numerical suspended sediment model to problems having analytical solutions, as well as to laboratory and field situations. The model is based upon an implicit finite-difference solution to a two-* dimensional (longitudinal and vertical) diffusion-advection equation for suspended sediment transport. Horizontal eddy diffusion is neglected in comparison with vertical diffusion and vertical water motion is assumed negligible in comparison with the sediment fall velocity. The various applications indicate that the greatest errors in the model are due to large spatial concentration gradients and that errors can be controlled by a suitable choice of space and time step. In addition, it is considered that the model has great flexibility and seems to have an acceptable level of accuracy, at least in the field situations tested, provided the physical parameters of the model can also be determined accurately.

scholarly journals Temporal variability of partially-contaminated sediments in a strongly regulated reservoir of the upper Rhine River

2018 ◽  
Vol 40 ◽  
pp. 04025
Author(s):  
Germain Antoine ◽  
Thomas Pretet ◽  
Matthieu Secher ◽  
Anne Clutier
Keyword(s):  
Suspended Sediment ◽  
Contaminated Sediments ◽  
Measured Data ◽  
Regulated River ◽  
Suspended Sediment Transport ◽  
Rhine River ◽  
Initial State ◽  
Time Step ◽  
Field Campaigns ◽  
Upper Rhine

The upper Rhine River is a highly harnessed and regulated river. EDF (a French electricity company) is in charge of eight dams on the upper Rhine River for producing hydro-electricity. In order to increase the safety and the competitiveness of the installations, but also to reduce their environmental impact, the sediment dynamics in these reservoirs has become a key factor to control and predict. In this study, we focused on the Marckolsheim reservoir, which is located 50 kilometers upstream the city of Strasbourg. Since its construction in 1961, this reservoir has been filled continuously with cohesive sediments, partially contaminated. Two field campaigns were performed in 2015 and 2016 under two different discharge conditions, with the objectives of quantifying the complex velocity fields on this site. The numerical codes TELEMAC-2D and SISYPHE were used to simulate in 2D the hydrodynamic and the suspended sediment transport of the reservoir. A ten kilometers long model was built and calibrated with the measured data of the 2015 and 2016 field campaigns, but also with measurements of sediment parameters that have been done separately. The originality of this model consists in an explicit 3D representation of the dam gates. An algorithm was implemented in TELEMAC in order to adapt the gates position at each time step, in conformity with the real regulation rules followed by the dam operator. By using upstream measured data of discharge and suspended sediment concentration, a four months period was simulated. The comparison of the simulated results with bathymetric surveys shows good agreements if specific properties of sediments related to settling processes are taken into account. Finally, the dynamics of the contaminated sediments was simulated. A 3D spatial distribution of the contaminated sediments in the reservoir was defined at the initial state by using in situ measurements. The fully coupled hydraulic-sediment-pollutant simulation performed over a single flood event gives first interesting highlights on the resuspension conditions of the contaminated sediments.

A two-dimensional computational model to simulate suspended sediment transport and bed changes

1999 ◽  
Vol 37 (3) ◽  
pp. 327-344 ◽  
Author(s):  
Reinaldo Garcia-Martinez ◽  
Ivan C Saavedra ◽  
Beatriz Febres De Power ◽  
Eduardo Valera ◽  
Carlos Villoria
Keyword(s):  
Sediment Transport ◽  
Computational Model ◽  
Suspended Sediment ◽  
Suspended Sediment Transport ◽  
Two Dimensional ◽  
Bed Changes

scholarly journals Two dimensional modelling of flood flows and suspended sedimenttransport: the case of the Brenta River, Veneto (Italy)

2004 ◽  
Vol 4 (1) ◽  
pp. 165-181 ◽  
Author(s):  
P. Martini ◽  
L. Carniello ◽  
C. Avanzi
Keyword(s):  
Suspended Sediment ◽  
Flood Risk ◽  
Tidal Flow ◽  
Venice Lagoon ◽  
Suspended Sediment Transport ◽  
Two Dimensional ◽  
Channel Network ◽  
Advection Dispersion ◽  
Continuity Equations ◽  
Diversion Channel

Abstract. The paper presents a numerical model for the simulation of flood waves and suspended sediment transport in a lowland river basin of North Eastern Italy. The two dimensional depth integrated momentum and continuity equations are modified to take into account the bottom irregularities that strongly affect the hydrodynamics in partially dry areas, as for example, in the first stages of an inundation process or in tidal flow. The set of equations are solved with a standard Galerkin finite element method using a semi-implicit numerical scheme where the effects of both the small channel network and the regulation devices on the flood wave propagation are accounted for. Transport of suspended sediment and bed evolution are coupled with the hydrodynamics using an appropriate form of the advection-dispersion equation and Exner's equation. Applications to a case study are presented in which the effects of extreme flooding on the Brenta River (Italy) are examined. Urban and rural flood risk areas are identified and the effects of a alleviating action based on a diversion channel flowing into Venice Lagoon are simulated. The results show that this solution strongly reduces the flood risk in the downstream areas and can provide an important source of sediment for the Venice Lagoon. Finally, preliminary results of the sediment dispersion due to currents and waves in the Venice Lagoon are presented.

scholarly journals theory of generalized diffusion on suspended sediment transport in the flows with mobile bed

1990 ◽  
Vol 12 (1) ◽  
pp. 7-13
Author(s):  
Nguyen Van Diep ◽  
Dang Huu Chung
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Suspended Sediment Transport ◽  
Bed Load ◽  
Two Dimensional ◽  
Mobile Bed ◽  
Dimensional Models ◽  
The One

In this work the authors have used the theory of generalized diffusion to establish the one and two-dimensional models describing suspended sediment transport in the flows with mobile bed. Here the exchange between suspended sediment and bed-load is taken into account. The set of equations obtained is closed by using the known experiment formulas.

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