摘要：Channel morphological change is often evaluated by employing
sediment transport models since field data during high magnitude low
frequency events is rarely available. However, sediment transport rate
estimates are heuristic at best to within 1 – 3 orders of magnitude. Mimico
Creek is an urban gravel-bed channel in Southern Ontario, Canada that has
undergone intensive event-based sediment transport sampling and interevent
bed material particle tracking over a three-year period. A HEC-RAS
model was developed of the study reach and calibrated to a series of
discharge events where in-situ bedload sampling occurred. Both step-wise
discharge and unsteady flow simulations were evaluated to compare
sediment transport rates for a range of transport models which included the
Meyer-Peter Müller and the Wilcock-Crowe. Calibration curves were
developed to estimate sediment discharge in Mimico Creek. The results of
the calibrated model were used to calculate the mean travel distance of bed
material using the expression for the volumetric rate of bed material
transport. Results from the modelling exercise found mean travel distances
were similar and in some cases larger than those observed from field
measurements, considering both mobile and immobile particles.
其他摘要：Channel morphological change is often evaluated by employing sediment transport models since field data during high magnitude low frequency events is rarely available. However, sediment transport rate estimates are heuristic at best to within 1 - 3 orders of magnitude. Mimico Creek is an urban gravel-bed channel in Southern Ontario, Canada that has undergone intensive event-based sediment transport sampling and inter-event bed material particle tracking over a three-year period. A HEC-RAS model was developed of the study reach and calibrated to a series of discharge events where in-situ bedload sampling occurred. Both step-wise discharge and unsteady flow simulations were evaluated to compare sediment transport rates for a range of transport models which included the Meyer-Peter Müller and the Wilcock-Crowe. Calibration curves were developed to estimate sediment discharge in Mimico Creek. The results of the calibrated model were used to calculate the mean travel distance of bed material using the expression for the volumetric rate of bed material transport. Results from the modelling exercise found mean travel distances were similar and in some cases larger than those observed from field measurements, considering both mobile and immobile particles.
