EN
Longitudinal changes in the granulometry of bar sediments were investigated in an 18 km long reach of the Czarny Dunajec to determine the impact of human activity in the river on depositional conditions in its channel. In the upper part of the reach, gravel extraction carried out in the past decades has led to deep channel incision and considerable coarsening of the bed material. Coarse, well sorted bar gravels occur also in the narrow, regulated channel sections in the middle part of the reach. Remarkably fine bed material typifies a wide, natural channel section in the lower part of the reach, and this section seems to function as a sediment sink, reducing bed-material delivery to a downstream located dam reservoir.