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A meander, in general, is a bend in a sinuous watercourse or river. A meander forms when moving water in a stream erodes the outer banks and widens its valley, and the inner part of the river has less energy and deposits silt. 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. The result is a ''snaking'' pattern as the stream meanders back and forth across its down-valley axis. When a meander gets cut off from the main stream, an oxbow lake forms. 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. There is not yet full consistency or standardization of scientific terminology used to describe watercourses. A variety of symbols and schemes exist. Parameters based on mathematical formulae or numerical data vary as well, depending on the database used by the theorist. Unless otherwise defined in a specific scheme "meandering" and "sinuosity" here are synonymous and mean any repetitious pattern of bends, or waveforms. In some schemes, "meandering" applies only to rivers with exaggerated circular loops or secondary meanders; that is, meanders on meanders. Sinuosity is one of the channel types that a stream may assume over all or part of its course. All streams are sinuous at some time in their geologic history over some part of their length. ==Origin of term== The term derives from the Meander River located in present-day Turkey and known to the Ancient Greeks as Μαίανδρος ''Maiandros'' (Latin: ''Maeander''),〔(【引用サイトリンク】title=Meander )〕 characterised by a very convoluted path along the lower reach. As such, even in Classical Greece (and in later Greek thought) the name of the river had become a common noun meaning anything convoluted and winding, such as decorative patterns or speech and ideas, as well as the geomorphological feature.〔(【引用サイトリンク】title= Meander )〕 Strabo said: "... its course is so exceedingly winding that everything winding is called meandering."〔Strabo, ''Geography'', Book 12 Chapter 8 Section 15.〕 The Meander River is located south of Izmir, east of the ancient Greek town of Miletus, now, Milet, Turkey. It flows through a graben in the Menderes Massif, but has a flood plain much wider than the meander zone in its lower reach. It's modern Turkish name is the Büyük Menderes River. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「meander」の詳細全文を読む スポンサード リンク
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