Flux saturation length of sediment transport

Abstract

Sediment transport along the surface drives geophysical phenomena as diverse as wind erosion and dune formation. The main length-scale controlling the dynamics of sediment erosion and deposition is the saturation length $L_{\mathrm{s}}$, which characterizes the flux response to a change in transport conditions. Here we derive, for the first time, an expression predicting $L_{\mathrm{s}}$ as a function of the average sediment velocity under different physical environments. Our expression accounts for both the characteristics of sediment entrainment and the saturation of particle and fluid velocities, and has only two physical parameters which can be estimated directly from independent experiments. We show that our expression is consistent with measurements of $L_{\mathrm{s}}$ in both aeolian and subaqueous transport regimes over at least five orders of magnitude in the ratio of fluid and particle density, including on Mars.

5 pages, 3 figures

References in corpus (6)

• The physics of wind-blown sand and dust
• Numerical simulation of turbulent sediment transport, from bed load to saltation
• Difference in the wind speeds required for initiation versus continuation of sand transport on Mars: Implications for dunes and dust storms
• Minimal size of a barchan dune
• Dune formation on the present Mars
• The apparent roughness of a sand surface blown by wind from an analytical model of saltation

Cited by in corpus (22)

• A unified model of ripples and dunes in water and planetary environments
• Unification of Aeolian and Fluvial Sediment Transport Rate from Granular Physics
• The Cessation Threshold of Nonsuspended Sediment Transport Across Aeolian and Fluvial Environments
• Analytical model for flux saturation in sediment transport
• Role of transverse displacements in the formation of subaqueous barchan dunes
• Birth of a subaqueous barchan dune
• Discrete Element Method simulations of the saturation of aeolian sand transport
• Direct validation of dune instability theory
• Spatial and temporal development of incipient dunes
• Aeolian sand transport: Scaling of mean saltation length and height and implications for mass flux scaling
• Dune initiation in a bimodal wind regime
• Analytical mesoscale modeling of aeolian sand transport
• Morphodynamics of barchan-barchan interactions investigated at the grain scale
• Modeling of Breaching Due to Overtopping Flow and Waves Based on Coupled Flow and Sediment Transport
• The formation and migration of sand ripples in closed conduits: experiments with turbulent water flows
• The fluctuation energy balance in non-suspended fluid-mediated particle transport
• Velocity fields and particle trajectories for bed load over subaqueous barchan dunes
• Field evidence for the initiation of isolated aeolian sand patches
• Formation of sand ripples under a turbulent liquid flow
• CFD simulation of the wind field over a terrain with sand fences: Critical spacing for the protected soil area
• Evolving dunes under flow reversals: from an initial heap toward an inverted dune
• Unified model of sediment transport threshold and rate across weak and intense subaqueous bedload, windblown sand, and windblown snow