Wpływ budowli piętrzącej na erozję denną koryta rzeki górskiej

In the paper negative effects of dams on a river bed below the structure are discussed. The linear erosion below the structure as a effect of Rożnów and Czchów dam on the Dunajec River and Dobczyce on Raba River is given as example. Analysis of this process is based on the minimum annual water stages in controlled cross-sections. Minimum annual water stages corresponds to the changes of river bed level. The changes of the position of the river bed in time is studied and analysed.