Prediction of time-dependent channel meander migration based on large-scale laboratory experiments

Abstract

Channel centreline migration rates were derived from a set of large-scale laboratory experiments. The channel radius of curvature, bend angle, and discharge were varied to evaluate correlations between the channel centreline migration rate and the controlling geometry and hydraulic conditions. An excessive Froude number was adopted to account for soil resistance strength. The intersection of the channel centreline between two consecutive time steps was identified. A phase lag of angle to channel curvature exists in both channel plan form and the onset of cross-section scour. The migration rate between two successive inflection points of migration exhibits a growth and decay pattern and is modelled using a sine function related to the channel geometry, the flow condition, and the soil property. A three-equation prediction method was developed and applied to a natural river in Texas.

Keywords:

• Meander migration
• migration rate
• secondary flow
• soil property
• thalweg

Acknowledgements

The authors wish to thank the financial support provided by the Texas Department of Transportation (TxDOT) under the project entitled “Establish guidance for soils properties-based prediction of meander migration rate”.