Which component is NOT part of floodplains?

Floodplains are flat or gently sloping areas adjacent to rivers and streams that are subject to flooding. They typically include a variety of components that play a role in how water flow and flooding are managed. The channel is the main body of water where the river or stream flows. The floodway refers to the area that carries most of the floodwater during peak flows, while the fringe, or floodplain fringe, is an area adjacent to the floodway that may also flood but does so less frequently or with less intensity.

Mountains, however, do not constitute a component of floodplains. They are typically higher elevation landforms that can influence water movement and patterns but are not part of the floodplain itself. The relationships within the floodplain components are essential in understanding flood management, ecology, and hydrology, while mountains are considered separate geographical features that can impact but do not belong to a floodplain.