TY - GEN
T1 - Determining the dynamics of coarse bedload transport using passive indirect monitoring: time-dependent variability at event to inter-annual scales
AU - Downs, Peter W.
AU - Soar, Philip J.
PY - 2018/9/5
Y1 - 2018/9/5
N2 - The dynamics of coarse bedload transport in rivers is governed by multiple hierarchical factors including catchment-scale controls on sediment production, annually variable hydroclimatic driving of segment-scale sediment supply, and reach-scale factors related to the interaction of hydraulic forces with channel morphology. Exploring hydroclimatic drivers can beneficially utilise passive sensors to record coarse bedload transport over extended time periods and in previously unattainable resolution. For the River Avon (Devon, UK), five-minute coarse bedload frequency data collected using seismic impact plates inherently records the instantaneous variability of bedload transport intensity, patterns of event-scale hysteresis and selective path transport, and the influence of inter-event supply variations. Converting a four-year record of impacts into loads via a probabilistic, data-driven model illustrates the combined influence of hydroclimate and sedimentology on bedload at the inter-annual scale. Despite highly variable water years, the results indicate that ‘bar-building flows’ consistently achieve the peak efficiency for coarse bedload transport whereas bankfull flows are relatively ineffective. Further, annual sediment rating curves combine both supply and transport limiting phases. Sediment transport forecasting is thus sensitive to both flow year type and antecedent controls on sediment supply, with implications for advancing sustainable solutions in river management.
AB - The dynamics of coarse bedload transport in rivers is governed by multiple hierarchical factors including catchment-scale controls on sediment production, annually variable hydroclimatic driving of segment-scale sediment supply, and reach-scale factors related to the interaction of hydraulic forces with channel morphology. Exploring hydroclimatic drivers can beneficially utilise passive sensors to record coarse bedload transport over extended time periods and in previously unattainable resolution. For the River Avon (Devon, UK), five-minute coarse bedload frequency data collected using seismic impact plates inherently records the instantaneous variability of bedload transport intensity, patterns of event-scale hysteresis and selective path transport, and the influence of inter-event supply variations. Converting a four-year record of impacts into loads via a probabilistic, data-driven model illustrates the combined influence of hydroclimate and sedimentology on bedload at the inter-annual scale. Despite highly variable water years, the results indicate that ‘bar-building flows’ consistently achieve the peak efficiency for coarse bedload transport whereas bankfull flows are relatively ineffective. Further, annual sediment rating curves combine both supply and transport limiting phases. Sediment transport forecasting is thus sensitive to both flow year type and antecedent controls on sediment supply, with implications for advancing sustainable solutions in river management.
UR - https://www.e3s-conferences.org/
U2 - 10.1051/e3sconf/20184005014
DO - 10.1051/e3sconf/20184005014
M3 - Conference contribution
VL - 40
T3 - E3S Web of Conferences
BT - River Flow 2018 - Ninth International Conference on Fluvial Hydraulics
A2 - Paquier, A.
A2 - Rivière, N.
PB - EDP Sciences
T2 - River Flow 2018: Ninth International Conference on Fluvial Hydraulics
Y2 - 5 September 2018 through 8 September 2018
ER -