ABSTRACTDetailed study was made of river channel changes occurring on low terraces in the Warta valley, west-central Poland. From paleobotanical and radiocarbon dates available for paleochannel fills, it has been inferred that a braided channel pattern remained active up to and including the Oldest Dryas. River metamorphosis took place during the Bølling, resulting in a meandering channel with high geometric parameters. From the Holocene they gradually declined due to an increase in forest density. The dated meandering paleochannels represented the starting point of quantitative assessment of annual discharge variations. The estimation was based on the measurement of paleochannel geometry, on the study of bed load deposits and on the reconstruction of velocity by use of the Manning and Strickler empirical formulae.