The Lower Odra is located between the Warta mouth and the Odra Roztoka. It has the character of lowland river, with low averaged energy gradients, smaller than 0.3‰. The flow of water and sediments takes place in the zone of subcritical movement. One can distinguish three sectors of Lower Odra, having different character: – the reach between the Warta mouth and Bielinek, behaving as a typical river, – the sector Bielinek – Gryfino, with influence of both river and sea, – the reach below Bielinek, typical for sea influence. The influence of wind and of high sea levels is marked mainly on the two last sectors. The transport of bed load, suspended load and wash load is observed in the whole Lower Odra. The bed sediments are composed mainly of sands and of fine gravels. Their grain size is decreasing in the downstream direction. The continuous bed load transport takes place in principle during the whole year. An important resistance component is this one concerning the bed load transport, related so to the grain roughness as to the bed forms roughness. The global coefficients of flow resistance for the Lower Odra were determined on the base of classic Manning formula ...
Estuary. During the winter inundations, this lake constitutes the receiver of ice jam from the river. This lake is intensively silted by river sediments type sand, silt and clay, delivered mainly by Regalica (the eastern branch of Odra) and by the rivers Ina and Płonia. The water volume of the lake decreased during 34 years (1962–1996) by 12,1 mln m3. The mean increase of sediments volume is equal 356 000 m3 * year-1. The processes of sedimentation and erosion of muds are complicated by the waving of water level and by superficial and bottom currents. These currents are generated so by river inflow as by wind, causing changes of sea level during storms. Through this lake goes the main navigation way between Schwedt and the Pomeranian Bay. Its deepening is planned in the period 2007–2011, by dredging of 810000 m3 of bed sediments. This fairway has following parameters: length 14,5 km, width 150 m and depth 10m. The geotechnic measurements have shown that the thickness of muds is equal 3-5 m. The cohesive sediments contain 10-30% of organic matter and have a liquid consistency. Below the organic sediments, mainly fine sands occur. The muds are polluted, mainly by heavy metals ...
