Anthropogenic influences on the morphodynamics of the upper Odra channel

The aim of the studies presented in this article was a multifaceted approach to the problem of the processes of river adjustments to new conditions created by channel regulation. The Upper Odra channel has been significantly shortened by meander cut offs and locally by channelization. The influence of those changes on channel morphodynamics and the pattern of bedload transport were calculated. Pre-regulation channel geometry was reconstructed and the channel stability and bedload transport were characterized and compared with the present state. Also the flow duration curves (FDC) for the characteristic water stages and for the average discharges were plotted and analyzed to assess vertical channel bed movement. By comparing the behavior of natural channel sectors (both, present and fossil) to channelized and sectors shortened by cut offs it was possible to understand the intensity of changes depending on a way of channel regulation. The range of post regulation changes in bedload transport and channel stability was also calculated for the functioning, unregulated sector of the Odra channel. Flow duration curves reflect steady channel incision while the protected river banks prevent the channel from lateral movement. In order to achieve lateral stability, which is unnatural for meandering rivers, the Odra channel is totally remodelled and the new geometry and flow conditions created. The morphological response to the training works was channel incision and accelerated bedload transport.