Suspended sediment concentration profiles in nonuniform flows: Is the classical perturbative approach suitable for depth-averaged closures?

2007 ◽  
Vol 43 (4) ◽  
Author(s):  
Marco Toffolon ◽  
Gianluca Vignoli
Keyword(s):  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Concentration Profiles ◽  
Perturbative Approach ◽  
Nonuniform Flows

scholarly journals COUPLED WAVE-BED DYNAMICS, ATCHAFALAYA SHELF, LOUISIANA

2012 ◽  
Vol 1 (33) ◽  
pp. 116
Author(s):  
Cihan Sahin ◽  
Ilgar Safak ◽  
Alexandru Sheremet
Keyword(s):  
Shear Stress ◽  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Critical Shear Stress ◽  
Flow Characteristics ◽  
Sediment Concentration ◽  
Density Variation ◽  
Acoustic Backscatter ◽  
Concentration Profiles ◽  
Fluid Mud

Observations of waves, currents, suspended sediment concentration and acoustic backscatter are used to re-investigate the interaction between the combined wave-current flow and cohesive sediments on the muddy Atchafalaya inner shelf. Observations support the previously proposed bed reworking cycle by waves of mobilization and resuspension of bed sediment, erosion, deposition with fluid mud formation and consolidation. Suspended sediment concentration profiles are estimated based on the acoustic backscatter of a current profiler. A one-dimensional vertical bottom boundary model is used to reconstruct the vertical structure of the flow characteristics, and estimate parameters difficult to observe directly, such as bottom shear stress. Estimated bed position, concentration profiles and computed bottom stresses remarkably support the previous findings on the bottom stress-resuspension relation, critical shear stress for erosion and bed density variation throughout a storm.

scholarly journals Appraisal of suspended sediment concentration on reference level according to van Rijn's method

2008 ◽  
Vol 40 (1) ◽  
pp. 67-76
Author(s):  
Bogusław Michalec
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Reference Level ◽  
Concentration Profiles ◽  
It Adoption ◽  
Vistula River ◽  
Preliminary Estimation

Appraisal of suspended sediment concentration on reference level according to van Rijn's method Appraisal of suspended sediment concentration on reference level according to van Rijn's method. The paper presents the results of sediment concentration measurements in the River Dłubnia at differentiated discharges of 0.44 m-3·s-1, 1.96 m-3·s-1 and 7.41 m-3·s-1. The elaborated concentration profiles based on hydrometric measurements permitted determination of Ca concentration on reference level "a" above the bed. The obtained reference concentrations were compared with the values obtained from calculations by use of van Rijn's formula. It was found that the calculated Ca concentration, applying the van Rijn's formula, is over five times higher than determined from concentration profiles. In order to obtain Ca concentration values, calculated by use of the empiric formula, approximate to real values coefficient correction must be determined. The elaborated preliminary estimation of the possibility of van Rijn's formula application for determination of this concentration on the reference level "a" above the bed showed that application of this method for appraisal of Ca concentration, by use van Rijn's formula, performed in the Dłubnia river of the catchment of the Upper Vistula river may be charged by errors. A faulty calculation of suspension sediment transport applying van Rijn's method may also point to it. Adoption of this method needs further verification and adaptation.

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