Amanda Balkus

University of South Carolina

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Juan J. Fedele

ExxonMobil (Germany)

E. Viparelli

University of South Carolina

Sadegh Jafarinik

University of South Carolina

Mahsa Ahmadpoor

University of South Carolina

Sydney Sanders

University of South Carolina

Ricardo Hernández Moreira

University of South Carolina

Brandon Fryson

University of South Carolina

Daniel Vázquez‐Tarrío

Instituto Geológico y Minero de España

Michal Tal

Centre de Recherche et d’Enseignement de Géosciences de l’Environnement

K. M. Hill

University of Minnesota

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University of South Carolina

University of Minnesota

University of Illinois Urbana-Champaign

Centre de Recherche et d’Enseignement de Géosciences de l’Environnement

Centre National de la Recherche Scientifique

Sustainable Europe Research Institute

Saint Anthony College of Nursing

Twin Cities Orthopedics

Urbana University

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Influence of Sand Supply and Grain Size on Equilibrium Upper Regime Bedforms

Journal of Geophysical Research Earth Surface (2023)

Sydney Sanders Sadegh Jafarinik Ricardo Hernández Moreira Ryan Johnson Amanda Balkus

Abstract Notwithstanding the large number of studies on bedforms such as dunes and antidunes, predicting equilibrium bedform type and geometry for a given flow regime, sediment supply and caliber remains an open problem. Here, we present results from laboratory experiments specifically designed to study how upper regime bedform type and geometry vary with sediment supply and caliber. Experiments were performed in a sediment feed flume with flow rates varying between 5 and 30 l/s and sand supply rates varying between 0.6 and 20 kg/min. We used both uniform and non‐uniform sands with geometric mean diameters varying between 0.22 and 0.87 mm. Analysis of our data and data available in the literature reveals that the ratio of total (bedload plus suspension) volume transport rate of sediment to water discharge Q s / Q w plays a prime control on upper regime equilibrium beds. Equilibrium bedforms transition from washed out dunes (lower regime) to downstream migrating antidunes (upper regime) for Q s / Q w between 0.0003 and 0.0007. For values of Q s / Q w greater than 0.0015, the bedform length increases with Q s / Q w . At these high values of Q s / Q w , equilibrium in fine sand is characterized by upstream migrating antidunes, cyclic steps, and significant suspended load. In experiments with coarse sand, equilibrium is characterized by plane bed with bedload transport in sheet flow mode. Standing waves form at the transition between downstream migrating antidunes and upstream migrating bedforms.

Bedform

Flume

10.1029/2022jf006820

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Citations (1)

Influence of sand supply and grain size on upper regime bedforms

Sydney Sanders Sadegh Jafarinik Ricardo Hernández Moreira Ryan B. Johnson Amanda Balkus

Earth and Space Science Open Archive This preprint has been submitted to and is under consideration at Journal of Geophysical Research - Earth Surface. ESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Influence of sand supply and grain size on upper regime bedformsAuthorsSydneySandersSadeghJafarinikRicardoHernández MoreiraiDRyanJohnsonAmandaBalkusMahsaAhmadpooriDBrandonFrysoniDBrianaMcQueenJuan JoseFedeleEnricaViparelliiDSee all authors Sydney SandersUniversity of South Carolinaview email addressThe email was not providedcopy email addressSadegh JafarinikUnknownview email addressThe email was not providedcopy email addressRicardo Hernández MoreiraiDUniversity of South CarolinaiDhttps://orcid.org/0000-0002-7929-7948view email addressThe email was not providedcopy email addressRyan JohnsonUniversity of South Carolinaview email addressThe email was not providedcopy email addressAmanda BalkusUniversity of South Carolinaview email addressThe email was not providedcopy email addressMahsa AhmadpooriDUniversity of South CarolinaiDhttps://orcid.org/0000-0002-5942-0179view email addressThe email was not providedcopy email addressBrandon FrysoniDUniversity of South CarolinaiDhttps://orcid.org/0000-0002-8905-0957view email addressThe email was not providedcopy email addressBriana McQueenUniversity of South Carolinaview email addressThe email was not providedcopy email addressJuan Jose FedeleExxon Mobilview email addressThe email was not providedcopy email addressEnrica ViparelliiDCorresponding Author• Submitting AuthorUniversity of South CarolinaiDhttps://orcid.org/0000-0001-6733-9664view email addressThe email was not providedcopy email address

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10.1002/essoar.10511834.1

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Streamwise and Vertical Dispersal of Tracer Stones in an Equilibrium Bed

Water Resources Research (2022)

E. Viparelli Amanda Balkus Daniel Vázquez‐Tarrío K. M. Hill Michal Tal

Abstract Modeling transport, erosion, and deposition of nonuniform sediment over temporal intervals that are short compared to those characterizing channel bed aggradation and degradation remains an open problem due to the complex quantification of the sediment fluxes between the bed material load and the alluvial deposit. Parker, Paola, and Leclair in 2000 proposed a morphodynamic (PPL) framework to overcome this problem. This framework is used here to model the dispersal of a patch of gravel tracers in three different settings, a laboratory flume, a mountain creek, and a braided river. To simplify the problem, (a) the bed slope, bedload transport rate, and bed configuration are assumed to be constant in space and time (equilibrium), (b) sediment entrainment and deposition are modeled with a constant step length formulation, and (c) the PPL framework is implemented in a one‐dimensional (laterally averaged) model. Model validation against laboratory experiments suggests that, as the transport capacity of the flow increases, the maximum elevation‐specific density of sediment entrainment may migrate downward in the deposit. The comparison between model results and field data shows that the equilibrium solution can reasonably capture tracer dispersal. The equilibrium model can also reproduce subdiffusion and superdiffusion of a patch of tracers in the streamwise direction, depending on the magnitude of the short‐term bed level changes. Finally, the average tracer elevation in a cross‐section decreases in time because particles that are buried deep in the deposit are only rarely reentrained into bedload transport.

Flume

Aggradation

Hyperconcentrated flow

Entrainment (biomusicology)

TRACER

Deposition

Bedform

10.1029/2022wr033137

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Citations (5)