The geochemical composition of sediments in naturally and anthropogenically formed abandoned meanders also differed due to the fact that the river tributaries drain two geologically contrasting areas, the Variscan Bohemian Massif and the Cretaceous-Cenozoic Outer Western Carpathians, respectively. The annual occurrence of low-magnitude floods was an important factor in the natural reaches of the Odra River. The accumulation rates were influenced by both local (oxbow lake size, position and geometry) and catchment-wide factors (sediment yield).
Relative to natural oxbow lakes, artificial lake successions revealed much slower sedimentation rates and higher levels of organic sedimentation and eutrophic conditions. In the naturally abandoned meanders, the initial stages of oxbow lake succession were characterised by extremely high sediment accumulation rates (up to 32 cm/yr), which caused the Stará Bělá abandoned meander to completely fill up over the course of several years. A lake that occupies a cutoff meander is known as an oxbow lake. Several site-specific factors controlled the sedimentation patterns. A meander cutoff also known as either a cutoff meander or abandoned meander is a meander that has been abandoned by its stream after the formation of a neck cutoff. In addition, two abandoned meanders formed by the artificial shortening of an upstream section of the Odra River were studied in order to compare processes in both sections. Two of the meanders were formed in non-regulated parts of the floodplain following a flood in 2010. The study is based on a combination of geomorphic observations, multi-proxy stratigraphic analysis and geochemistry of sediment cores in four abandoned meanders of the Odra River, in the northeastern part of the Czech Republic. We provide an insight into the initial stages of oxbow lake evolution in terms of morphology, dynamics, sediment accumulation rates, sediment architecture and switching between sediment source areas. Natural and artificial oxbow lakes may differ considerably, although both can offer unique sedimentary records of recent past events in river catchments. All streams are sinuous at some time in their geologic history over some part of their length.Oxbow lakes represent important geomorphic and depositional units of meandering river systems, whose rates of sediment accumulation may significantly exceed those of surrounding floodplains. Sinuosity is one of the channel types that a stream may assume over all or part of its course. In some schemes, "meandering" applies only to rivers with exaggerated circular loops or secondary meanders that is, meanders on meanders. Unless otherwise defined in a specific scheme "meandering" and "sinuosity" here are synonymous and mean any repetitious pattern of bends, or waveforms. Parameters based on mathematical formulae or numerical data vary as well, depending on the database used by the theorist. Condition in which molecular oxygen is present in the environment. A former stream channel that was cut off from the rest of the river and typically lacks yearlong standing water.
ABANDONED MEANDER FULL
There is not yet full consistency or standardization of scientific terminology used to describe watercourses. Abandoned Meander Channel Wetland Terms (Riparian and Wetland Research Program) Abandoned Meander Channel. Over time meanders migrate downstream, sometimes in such a short time as to create civil engineering problems for local municipalities attempting to maintain stable roads and bridges. When a meander gets cut off from the main stream, an oxbow lake is formed. The result is a snaking pattern as the stream meanders back and forth across its down-valley axis. A stream of any volume may assume a meandering course, alternately eroding sediments from the outside of a bend and depositing them on the inside. A meander is formed when the moving water in a stream erodes the outer banks and widens its valley. A meander, in general, is a bend in a sinuous watercourse or river.
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