The rate of sedimentation on regulated river floodplains: The upper Vistula and the upper Odra Rivers, Southern Poland.

The upper Odra and the upper Vistula Rivers used to be naturally meandering rivers. The embankment constructions confined the river floodplain and changed the natural pattern of alluvial sedimentation. Regulation works arrested the lateral migration of the Vistula River. The Odra River course has been straightened. Differences in sedimentation in such different environments are noticeable. The flood sediments create the vertical v accreted alluvia. The three different indicators were used to define sediment age. Due to 200 years of hard coal mining the finds of coal dust in the lowest parts of the profiles indicates that the surveyed sequence was deposited during the last 200 years. Upper parts of the alluvia also contain plastic objects (artefacts) and (CS)-C-137 which were used to provide age estimates. Their presence proves that the deposits are relatively young and the rate of sedimentation seems to be rapid.