Flow Strength and Bedload Sediment Travel Distance in Gravel Bed Rivers

Abstract

Characterizing the advection and dispersion of gravel bedload particles in response to fluid flow is a longstanding problem in river hydraulics. At the smallest or "local" scale, bed sediment movement is characterized by a series of individual hops and rests referred to as the transport step length and waiting time (Hassan & Bradley, 2017;Nikora et al., 2002). At a larger or "global" scale, the cumulative motion over floods, seasons, or years can be measured to obtain an overall "travel distance" ( 𝐴𝐴 𝐴𝐴 ; Hassan & Bradley, 2017;Nikora et al., 2002). Advances in bedload tracers have allowed us perhaps the best opportunity to observe the kinematics and untangle the controls of gravel transport (Hassan & Roy, 2016). Active tracers have internal batteries used to power accelerometers, recorders, or transmitters, that can be used to characterize motion on the local scale (Cassel

Modelling Coarse-Sediment Propagation Following Gravel Augmentation: The Case of the Rhône River at Péage-De-Roussillon (France)

“…Unfortunately, no previous research has found a relatively simple and universal relation linking the mean travel distances of fluvial sediment to peak discharge or basic hydraulic parameters. In fact, previous research showed how mean travel distances depend on both peak discharge and the duration of flow (Phillips et al, 2018;Gervasi et al, 2021), but this relation shows a large variability and tends to be site specific (Haschenburger, 2013;Papangelakis and Hassan, 2016;Papangelakis et al, 2022). Nevertheless, Haschenburger (2013), Papangelakis and Hassan (2016) and Papangelakis et al (2022) observed that mean travel distances are locally well correlated with the excess stream power or energy according to linear or power relationships of the kind:…”

“…As a result, there are plenty of available equations that provide more or less reliable estimates of bedload rates (Vázquez-Tarrío and Menéndez-Duarte, 2015;Hinton et al, 2018). The second question relates to the Lagrangian approach to bedload transport, and is a much more complex problem because of the lack of comparable formulae linking travel distances to discharge (Papangelakis et al, 2022). This is caused in large part to the complex nature of gravel propagation, involving a combination of translation, diffusion, and dispersion (Lisle et al, 2001).…”

“…Previous research reported that travel lengths tend to follow either an exponential or a gamma distribution (Hassan et al, 1991;Lamarre and Roy, 2008;Bradley & Tucker, 2012;Liébault et al, 2012;Hassan et al, 2013;Phillips and Jerolmack, 2014;Olinde and Johnson, 2015;Papangelakis and Hassan, 2016). In principle, an exponential distribution best describes situations where a large proportion of particles remain immobile or move only short distances, whereas a gamma distribution is best suited to cases where many particles travel far from their seeding locations (Hassan et al, 1991;Pyrce and Ashmore, 2003;Papangelakis et al, 2022). The exponential probability distribution is a single parameter distribution, requiring only the definition of the rate parameter λ:…”

“…Although it is true that many of them have been validated with field data (e.g., the Navarro River in Cui et al, 2006aCui et al, , 2006b; the Ain River in Lauer et al, 2016; the Buëch River in Viparelli et al, 2022), in almost none of these models is information derived directly from field observations collected in rivers used in the calibration or in the definition of model parameters, which represents a major limitation. To the best of our knowledge, this fact is likely related to the lack of robust and strong functional relations linking water discharge to the distances or velocities of sediment propagation observed in the field (Hassan and Bradley, 2017;Klösch and Habersack, 2018;Papangelakis et al, 2022), which is indeed an elusive (although longstanding) topic in river research. In this regard, particle tracking has probably been the most popular strategy for the field study of fluvial gravel displacement (and dispersion) along river channels (Hassan and Roy, 2016), and much research effort has been invested in tracking particle displacements in gravel-bed rivers using tagged stones.…”

“…In this regard, particle tracking has probably been the most popular strategy for the field study of fluvial gravel displacement (and dispersion) along river channels (Hassan and Roy, 2016), and much research effort has been invested in tracking particle displacements in gravel-bed rivers using tagged stones. Such tracer research has helped to disentangle the nature of the multiple controls behind gravel transport (Hassan and Bradley, 2017;Vázquez-Tarrío et al, 2019a, 2019bMcQueen et al, 2021), which include the magnitude and duration of discharge (Phillips and Jerolmack, 2014;Houbrechts et al, 2015;Papangelakis et al, 2022), channel morphology (Pyrce and Ashmore, 2003;McQueen et al, 2021;Peeters et al, 2021), macro-bedforms (Vázquez-Tarrío et al, 2019b), grain-size (Church and Hassan, 1992), active-layer fluctuations (Haschenburger, 1999;, and the length scale of the channel (Beechie, 2001;Vázquez-Tarrío and Batalla, 2019). All this previous work has undoubtedly contributed to providing us with a clearer idea on how bedload behaves and how the controls on gravel displacements observed in the field largely depend on the scale of the study (Vázquez-Tarrío and Batalla, 2019).…”