What is a braided river defined by?

A braided river is characterized by multiple interconnecting shallow channels that weave around small islands or bars of sediment. This unique formation occurs when the river carries a high sediment load, often in areas with variable water flow, which results in the sediment being deposited in the riverbed. As the river flows, it splits into several smaller channels, which gives it a 'braided' appearance, similar to the intertwining strands of a braid.

The presence of these multiple channels is crucial; they create a complex network and enhance the dynamic nature of the river as it shifts in response to water levels and sediment availability. This contrasts with the other options, which do not capture the essence of a braided river's structure and behavior. For instance, a single channel suggests a more linear flow, a steep gradient points to the slope of the river which typically leads to different river types, and a delta formation refers to the area where a river meets a body of water and deposits sediment, rather than how the river's channels are configured.