Abstract
Undular bores, sometimes called Favre Waves, occur in channels for navigation, irrigation, power production. They are investigated for rectangular and trapezoidal cross-sections by comparing analytical and numerical models with experimental data. Undular bores in trapezoidal channels are shown to differ significantly from those in rectangular channels; waves are higher above the embankments than in the center. An extension of the Boussinesq wave theory has been used succesfully to describe these phenomena.