Channel (geography)

In physical geography and hydrology, a channel is a landform on which a relatively narrow body of water sits, such as a river, river delta or strait. Channels are distinguished from canals, the equivalent artificial structure built by human engineering, though people also maintain and reshape natural channels through dredging to keep them navigable for shipping and ports. The dimensions of a natural channel shift over time as flowing water erodes and redeposits material along its course, and the same term extends to passages carved by other fluids, including lava channels on Earth and channel-like surface features identified on Venus.