![]() Oxbows along the West Branch Ausable River near Lake Placid, along River Road, are easily visible on Google satellite views they indicate the river's former path prior to the Ausable's logging era. Eventually, the meander may be cut off from the main channel, forming an oxbow lake. Give with confidence today!Įrosion in a stable stream can be minimal from year to year, but as a meander moves outward and becomes more looped, flows intensify on the outer bends. Support our Natural Stream Restoration efforts to recreate stable channels based on the hydrology and hydraulics that shape natural channels. Further downstream, moving out of the bend, the channel straightens, and the channel cross-section becomes more uniform through the riffle. In these pool and bend sections, one side of the channel is significantly deeper. As every angler knows, deep pools form on the outer bends of meanders, with low sloping point bars of accumulated gravel or cobble on the inside bends. This process reinforces the riffle-pool structure of a stream. Meanders are produced when water in the stream channel erodes the sediments of an outer bend of a streambank and deposits this and other sediment on subsequent inner bends downstream. Remember, streams are transport machines, moving water and sediment from their watersheds relentlessly downslope. ![]() Streams meander to maintain equilibrium – a dynamically stable form and function. The geometry of the meander minimizes the amount of work, or energy expended, while using that same energy uniformly. Those bends and turns manage the energy of water, as it moves through and over channel terrain, by increasing resistance and reducing channel gradient. On broad, low-slope plains, streams thread back and forth. In steep topography, channels are straighter, influenced by slope and confined by valleys. They are sinuous, with channels that bend, curve, or loop. In conclusion, the formation of an oxbow lake is a result of the erosion and deposition process that occurs in meandering rivers, which causes the bends to become more pronounced over time, eventually leading to the formation of a crescent-shaped lake when the river breaks through the neck of a meander during a flood.When you see a stream from the air, from a plane or a satellite photo, one thing is quickly apparent: streams meander. The river then continues to flow along this new channel, leaving behind a crescent-shaped oxbow lake. The force of the water can erode the neck, causing it to break through and creating a new, straighter channel. Over time, the bend becomes more pronounced, with the river channel becoming narrower and deeper on the outer banks, and shallower and wider on the inner banks.ĭuring a flood, the river may overflow its banks, causing water to flow across the narrow neck of the meander. This causes the outer banks to be eroded, while the inner banks are deposited with sediment. As water flows downstream, it follows the path of least resistance, which tends to be along the outer banks of a bend. The formation of an oxbow lake can be explained by the process of erosion and deposition that occurs in meandering rivers. The river then takes a new, straighter course, leaving behind a crescent-shaped oxbow lake. Over time, this erosion and deposition cause the bend to become more pronounced, until the neck of the meander narrows and eventually breaks through during a flood. (6 marks)Īn oxbow lake is formed when a meandering river or stream erodes the outer banks of a bend, while the inner banks are deposited with sediment. ![]() Describe and explain the formation of an oxbow lake.
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