000202439 001__ 202439
000202439 005__ 20190317000031.0
000202439 0247_ $$2doi$$a10.1002/2013Jf003003
000202439 022__ $$a2169-9003
000202439 02470 $$2ISI$$a000342516400005
000202439 037__ $$aARTICLE
000202439 245__ $$aSpatial correlations in bed load transport: Evidence, importance, and modeling
000202439 260__ $$bAmer Geophysical Union$$c2014$$aWashington
000202439 269__ $$a2014
000202439 300__ $$a17
000202439 336__ $$aJournal Articles
000202439 520__ $$aThis article examines the spatial {dynamics of bed load particles} in water. We focus particularly on the fluctuations of particle activity, which is defined as the number of moving particles per unit bed {length}. Based on a stochastic model recently proposed by \citet{Ancey2013}, we derive the second moment of particle activity analytically; that is the spatial correlation functions of particle activity. From these expressions, we show that large moving particle clusters can develop spatially. Also, we provide evidence that fluctuations of particle activity are scale-dependent. Two characteristic lengths emerge from the model: a saturation length $\ell_{sat}$ describing the length needed for a perturbation in particle activity to relax to the homogeneous solution, and a correlation length $\ell_c$ describing the typical size of moving particle clusters. A dimensionless P\'eclet number can also be defined according to the transport model. Three different experimental data sets are used to test the theoretical results. We show that the stochastic model describes spatial patterns of particle activity well at all scales. In particular, we show that $\ell_c$ and $\ell_{sat}$ may be relatively large compared to typical scales encountered in bed load experiments (grain diameter, water depth, bed form wavelength, flume length...) suggesting that the spatial fluctuations of particle activity have a non-negligible impact on the average transport process.
000202439 700__ $$0245055$$g207047$$uEcole Polytech Fed Lausanne, Sch Architecture Civil & Environm Engn, Lab Environm Hydraul, Lausanne, Switzerland$$aHeyman, J.
000202439 700__ $$aMa, H. B.
000202439 700__ $$0242290$$g198336$$uEcole Polytech Fed Lausanne, Sch Architecture Civil & Environm Engn, Lab Environm Hydraul, Lausanne, Switzerland$$aMettra, F.
000202439 700__ $$aAncey, C.$$uEcole Polytech Fed Lausanne, Sch Architecture Civil & Environm Engn, Lab Environm Hydraul, Lausanne, Switzerland$$g148669$$0240366
000202439 773__ $$j119$$tJournal Of Geophysical Research-Earth Surface$$k8$$q1751-1767
000202439 8564_ $$uhttps://infoscience.epfl.ch/record/202439/files/jgrf20281-2%20heyman%20-%20ancey%20lhe-epfl.pdf$$zn/a$$s2158720$$yn/a
000202439 909C0 $$xU10257$$0252029$$pLHE
000202439 909CO $$ooai:infoscience.tind.io:202439$$qGLOBAL_SET$$particle$$pENAC
000202439 917Z8 $$x106556
000202439 917Z8 $$x106556
000202439 917Z8 $$x106556
000202439 937__ $$aEPFL-ARTICLE-202439
000202439 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000202439 980__ $$aARTICLE