Effect of Flood Hydrograph Duration, Magnitude, and Shape on Bed Load Transport Dynamics

C. B. Phillips, K. M. Hill, C. Paola, M. B. Singer, D. J. Jerolmack

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Bed load sediment transport is an inherently challenging process to measure within a river, which is further complicated by the typically transient nature of the hydrograph. Here we use laboratory experiments to explore how sediment flux under transient—unsteady and intermittent—flow differ from those under steady flow. For a narrow unimodal sediment distribution, we calculated fluid stress and measured sediment flux for a range of hydrograph durations, magnitudes, shapes, and sequences. Within a hydrograph, we find considerable variability in sediment flux for a given stress above the threshold for motion. However, cumulative bed load flux resulting from a flood scales linearly with the integrated excess transport capacity (flow impulse). This scaling indicates that, to first order, flow magnitude, duration, shape, and sequence are only relevant to bed load flux in terms of their contribution to the total flow impulse, in agreement with prior field results. The flood impulse represents a quantitative parameter through which the effects of transient flow on coarse sediment transport may be parsed.

Original languageEnglish (US)
Pages (from-to)8264-8271
Number of pages8
JournalGeophysical Research Letters
Volume45
Issue number16
DOIs
StatePublished - Aug 28 2018

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bedload
hydrograph
beds
sediments
impulses
sediment transport
sediment
transient flow
steady flow
rivers
fluid
effect
scaling
river
thresholds
fluids

Keywords

  • experiment
  • floods
  • geomorphology
  • hydrograph
  • rivers
  • sediment transport

Cite this

Effect of Flood Hydrograph Duration, Magnitude, and Shape on Bed Load Transport Dynamics. / Phillips, C. B.; Hill, Kimberly M; Paola, Chris; Singer, M. B.; Jerolmack, D. J.

In: Geophysical Research Letters, Vol. 45, No. 16, 28.08.2018, p. 8264-8271.

Research output: Contribution to journalArticle

Phillips, C. B. ; Hill, K. M. ; Paola, C. ; Singer, M. B. ; Jerolmack, D. J. / Effect of Flood Hydrograph Duration, Magnitude, and Shape on Bed Load Transport Dynamics. In: Geophysical Research Letters. 2018 ; Vol. 45, No. 16. pp. 8264-8271.
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