A canyon is a deep, narrow valley with steep sides, typically formed by long-term river erosion.
Rivers sculpt the land via hydraulic action, abrasion, and corrosion, eventually creating these profound channels.
An instance is the Grand Canyon in the United States, shaped by the Colorado River over millennia.
Conversely, a delta forms from sediment deposited by a river as its speed diminishes upon entering a body of still water.
Plateaus are elevated, flat regions, and sand dunes originate from wind, not water.