[3] The channels and braid bars are usually highly mobile, with the river layout often changing significantly during flood events.
[2][8][10] Experiments with flumes suggest that a river becomes braided when a threshold level of sediment load or slope is reached.
[11] These experimental results were expressed in formulas relating the critical slope for braiding to the discharge and grain size.
Variable discharge has also been identified as important in braided rivers,[13] but this may be primarily due to the tendency for frequent floods to reduce bank vegetation and destabilize the banks, rather than because variable discharge is an essential part of braided river formation.
Braiding is not observed in simulations of the extreme cases of pure scour (no deposition taking place), which produces a dendritic system, or of cohesive sediments with no bedload transport.
[17] Extensive braided river systems are found in Alaska, Canada, New Zealand's South Island, and the Himalayas, which all contain young, rapidly eroding mountains.