jokiadaankääntymiseen

Jokihaankääntymiseen, often translated as "river bend turning" or "river meander transformation," refers to a geomorphological process where a river's course changes over time, leading to the formation of oxbow lakes. This phenomenon is a natural part of fluvial geomorphology and occurs in the depositional environments of river floodplains.

The process begins with erosion. As a river flows, it exerts greater force on the outer bank of a bend, causing it to erode and widen. Simultaneously, the inner bank of the bend experiences deposition of sediment due to reduced flow velocity. This differential erosion and deposition causes the meander to become more pronounced, forming a tighter curve.

Over time, the neck of land separating two successive bends can become increasingly narrow. During periods of high flow, such as floods, the river may cut across this narrow neck, establishing a straighter and shorter channel. The old, abandoned meander loop, no longer receiving flowing water, becomes isolated from the main river channel.

As the water within the isolated loop gradually stagnates, sediment deposition continues, eventually filling in the oxbow lake and transforming it into a crescent-shaped feature on the floodplain. These oxbow lakes are distinctive landforms that provide evidence of past river courses and the dynamic nature of river systems. They can also create unique habitats for a variety of flora and fauna.