Predicting Meander Migration: Evaluation of Some Existing Techniques (0-2105-1)

River meanders migrate over time; this migration endangers civil engineering structures in general and highway bridges in particular. The geotechnical engineer and the hydraulic engineer work together to predict and prevent this migration. This article describes and evaluates two approaches used to predict the migration of meanders: the empirical approach and the time-sequence maps and extrapolation approach. Empirical methods are based on correlations using databases of observed behavior, while the time-sequence method uses previously observed movement of a given meander to predict its future migration. Six case histories on four rivers are used to evaluate the precision and accuracy of these methods by comparing the predicted and measured migration. The results show that some empirical methods are conservative, some are unconservative, and none of them are very accurate or precise. The time sequence method gives more information on the meander movement, is relatively precise and accurate in predicting the radius of the bestfit circle of the future meander location, but is not precise in predicting the migration rate of the center of that circle.