I believe this to be Kokshaga River (pictures here).
A meander is a bend in a river, also known as an oxbow loop. A stream or river flowing through a wide valley or flat plain will tend to form a meandering stream course as it alternatively erodes and deposits sediments along its course. The result is a snaking pattern as the stream meanders back and forth across its floodplain. When a meander gets cut off from the main stream body, an oxbow lake is formed.