What type of stream channel typically has a high gradient and is composed of bedrock?

A stream channel characterized by a high gradient and composed of bedrock is referred to as a bedrock channel. These channels are typically found in mountainous or steep terrain where the gradient of the stream is steep enough that water flows quickly over solid rock. The lack of significant sediment deposition in these environments means that the stream is often confined to a narrow pathway, shaped primarily by the underlying geological structure.

Bedrock channels contrast with other types, such as meandering channels, which usually have a lower gradient and are defined by their sinuous paths formed by erosion and deposition of sediments. Alluvial channels, on the other hand, are composed of loose sediments that are constantly reshaped by the flowing water, and these channels often have a more gentle slope. Artificial channels are man-made constructs that can vary widely in design and materials used, often lacking the natural characteristics that define bedrock channels.

In summary, a bedrock channel's defining features—its high gradient and solid rock composition—allow it to produce fast and turbulent water flow, making it distinct from other channel types.