Estimation of Bed Load Transport Rate Based on Grain Froude Similarity Considering the Existence of Sand Waves

2010 ◽  
Vol 148-149 ◽  
pp. 30-35
Author(s):  
Bing Qian Wei ◽  
Hong Yun Xun ◽  
Xiao Jun Sun ◽  
Rong Ge Xiao
Keyword(s):  
Froude Number ◽  
Satisfactory Result ◽  
Model Experiment ◽  
Transport Rate ◽  
Bed Load ◽  
Sand Waves ◽  
Estimation Formula ◽  
Bed Forms ◽  
Load Transport ◽  
Bed Load Transport

It is very important for reservoir management to estimate the sedimentation amount deposited in a reservoir. Firstly, the formula for estimating the bed load transport rate in the bed of sand waves of prototype by model experiment was derived based on the similarity of grain Froude number; Secondly, several model experiments that the bed forms is similar with the prototype were carried, and the formula was verified. As a result, when the ratio of grain diameter in the prototype and model is great enough, and the bed forms in the model is similar with that in the prototype, a satisfactory result can be obtained by using the estimation formula for estimating the bed load transport rate of the prototype that sand waves occur in the bed.

scholarly journals Evaluation of an acoustic Doppler technique for bed-load transport measurements in sand-bed Rivers

2018 ◽  
Vol 40 ◽  
pp. 02053 ◽  
Author(s):  
S. Conevski ◽  
A. Winterscheid ◽  
N. Ruther ◽  
M. Guerrero ◽  
C. Rennie
Keyword(s):  
Transport Model ◽  
Transport Rate ◽  
Qualitative Assessment ◽  
Bed Load ◽  
Apparent Velocity ◽  
Digital Cameras ◽  
Statistical Correlations ◽  
Hydraulic Conditions ◽  
Load Transport ◽  
Bed Load Transport

The bottom tracking (BT) feature of the acoustic Doppler current profilers (ADCP) have emerged as a promising technique in evaluating the bed load. Strong statistical correlations are reported between the ADCP BT velocity and the transport rate obtained by physical sampling or dune tracking; however, these relations are strictly site-specific and a local calibration is necessary. The direct physical sampling is very labor intensive and it is prone to high instrument uncertainty. The aim of this work is to develop a methodology for evaluating the bed load transport using commercial ADCPs without calibration with physical samples. Relatively long stationary measurements were performed in a sand-bed and sand gravel rivers, using three different ADCPs working at 3MHz, 1.2MHz and 0.6MHz. Simultaneously, bed load samples were collected with physical samplers, and the riverbed was closely observed with digital cameras mounted on the samplers. It is demonstrated that the kinematic transport model can yield a relatively good estimate of the transport rate by directly using filtered apparent velocity, the knowledge of the hydraulic conditions and instrument-related calibration coefficients. Additionally, the ADCP data can help in qualitative assessment of the physical sampling. Future investigation of the backscattering echo and further confirmation of the BT apparent velocity should be performed in laboratory-controlled conditions.

scholarly journals Comparison between Computations and Measurements of Bed Load Transport Rate in Nestos River, Greece

2016 ◽  
Vol 162 ◽  
pp. 172-180 ◽  
Author(s):  
Thomas Papalaskaris ◽  
Paraskevi Dimitriadou ◽  
Vlassios Hrissanthou
Keyword(s):  
Transport Rate ◽  
Bed Load ◽  
Nestos River ◽  
Load Transport ◽  
Bed Load Transport

scholarly journals Advection and dispersion of bed load tracers

2018 ◽  
Vol 6 (2) ◽  
pp. 389-399 ◽  
Author(s):  
Eric Lajeunesse ◽  
Olivier Devauchelle ◽  
François James
Keyword(s):  
Steady State ◽  
Steady Flow ◽  
Constant Velocity ◽  
Transport Rate ◽  
Bed Load ◽  
Deposition Model ◽  
Advection Diffusion ◽  
Maximum Value ◽  
Load Transport ◽  
Bed Load Transport

Abstract. We use the erosion–deposition model introduced by Charru et al. (2004) to numerically simulate the evolution of a plume of bed load tracers entrained by a steady flow. In this model, the propagation of the plume results from the stochastic exchange of particles between the bed and the bed load layer. We find a transition between two asymptotic regimes. The tracers, initially at rest, are gradually set into motion by the flow. During this entrainment regime, the plume is strongly skewed in the direction of propagation and continuously accelerates while spreading nonlinearly. With time, the skewness of the plume eventually reaches a maximum value before decreasing. This marks the transition to an advection–diffusion regime in which the plume becomes increasingly symmetrical, spreads linearly, and advances at constant velocity. We analytically derive the expressions of the position, the variance, and the skewness of the plume and investigate their asymptotic regimes. Our model assumes steady state. In the field, however, bed load transport is intermittent. We show that the asymptotic regimes become insensitive to this intermittency when expressed in terms of the distance traveled by the plume. If this finding applies to the field, it might provide an estimate for the average bed load transport rate.

scholarly journals BED LOAD TRANSPORT DUE TO NON-LINEAR WAVE MOTION

1988 ◽  
Vol 1 (21) ◽  
pp. 133 ◽  
Author(s):  
Hitoshi Tanaka
Keyword(s):  
Sediment Transport ◽  
Wave Motion ◽  
Surf Zone ◽  
Function Theory ◽  
Transport Rate ◽  
Bed Load ◽  
Linear Wave ◽  
Wave Flume ◽  
Load Transport ◽  
Bed Load Transport

The bed load transport rate due to wave motion is measured in a wave flume. The modified stream function theory of the author ( Tanaka (1988) ) is applied to the formulation of the sediment transport rate in order to include the non-linearity. The proposed formula predicts well except near the surf zone where the effect of the acceleration plays an important role.

scholarly journals The Application of Radioactive Tracers for Determination of Bed-Load Transport in Alluvial Rivers

1980 ◽  
Vol 11 (3-4) ◽  
pp. 133-144 ◽  
Author(s):  
Thorkild Thomsen
Keyword(s):  
Radioactive Isotopes ◽  
Bed Load ◽  
Alluvial Rivers ◽  
Tracer Particles ◽  
Bed Forms ◽  
Load Transport ◽  
Bed Load Transport ◽  
Tracer Methods ◽  
The Difference

Radioactive isotopes have been applied for determining the transport rate of bed load in an alluvial river on the basis of: centroid velocity of the tracer particles, size and material-transporting width of mobile layer. These parameters were found by detailed measurements in the field. Computed values were produced on the basis of Engelund and Fredsøe's model on sediment transport (1976) and on the propagation of bed forms. When comparing measured and computed values, the difference was about 25%. Finally, the applicability of tracer methods for solving practical problems is discussed.

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