braidedchannel

A braided channel is a type of river channel characterized by a network of interconnected channels that split and rejoin around mid-channel sediment bars rather than forming a single continuous trough. This pattern is common in alluvial rivers where sediment supply is high and flow is variable, producing a mosaic of gravel and sand bars that migrate with discharge.

Braided channels form under conditions of high sediment load relative to transport capacity, often in catchments with steep gradients, glacial or volcanic inputs, or arid regions with episodic floods. They also occur where channels have frequently shifting beds and banks due to grain-size distributions dominated by coarse material.

Morphology and dynamics: The channel system comprises many small, shallow channels that braid around mobile bars. The overall planform has low sinuosity, and the braided network is highly dynamic, with channels constantly shifting or avulsing as sediment is eroded and deposited. During floods, water is distributed among several channels; in low flow, channels may constrict or dry, while bars become exposed.

Ecology and management: Braided rivers support diverse habitats and high geomorphic complexity but pose challenges for navigation, infrastructure, and flood control. Management approaches emphasize maintaining sediment routing and channel mobility rather than rigid stabilization, to avoid eliminating natural processes.

Examples: Notable braided rivers include the Mackenzie River in Canada and the Brahmaputra in parts of its course through India and Bangladesh, as well as many rivers in Iceland and New Zealand.

Measurement: Researchers use the braiding index (average number of channels), sinuosity, and bar mobility to characterize braided systems.