Flood and vortex scour of the channel bed of the Prosna river,and their depth range

Flood and vortex scour were observed in the Prosna channel (Central Poland) in the years 1980–1985. Flood scour increases the thickness of the reworked channel deposits by 30 per cent to 66 per cent, in relation to the thickness determined by the elevation of the normal bed and the bankfull stage. Vortex scour can increase the thickness by as much as 90–95 per cent. Knowledge of these properties of contemporary alluvium allows correct palaeohydrological and stratigraphic interpretation of the alluvial fills of valley floors.