Which type of stream channel is formed by sediments deposited by water flow?

An alluvial channel is formed by sediments that are deposited as a result of flowing water. This type of channel is created when sediment—such as sand, silt, and clay—accumulates in the stream's path, which can occur during periods of high water flow or flooding. The water's velocity decreases, allowing sediment to settle and form a channel characterized by its variable shape and width, often subject to changes in flow conditions and sediment supply.

In contrast, a bedrock channel typically features a solid rock substrate with little to no sediment deposition, which shapes the stream's path over time through erosion rather than deposition. An artificial channel is engineered by humans for various purposes, such as irrigation or flood control, rather than formed naturally through sediment processes. A meandering channel refers to the winding path of a stream that typically occurs in areas with fine sediments, but it does not exclusively refer to the deposition process itself. Thus, the defining characteristic of an alluvial channel—being shaped primarily by sediment deposition—is what distinguishes it clearly from the other types of channels mentioned.