A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely at the end of its course, and does not reach another body of water. Small rivers may be called by several other names, including stream, creek, brook, rivulet, and rill. There are no official definitions for generic terms, such as river, as applied to geographic features, although in some countries or communities a stream may be defined by its size. Many names for small rivers are specific to geographic location; examples are "run" in the United States, "burn" in Scotland and northeast England, and "beck" in northern England. Sometimes a river is defined as being larger than a creek, but not always: the language is vague.
Rivers are part of the hydrological cycle. Water generally collects in a river from precipitation through a drainage basin from surface runoff and other sources such as groundwater recharge, springs, and the release of stored water in natural ice and snowpacks (e.g. from glaciers). Potamology is the scientific study of rivers while limnology is the study of inland waters in general.
No extraterrestrial rivers are currently known, though large flows of hydrocarbons described as rivers have recently been found on Titan. Channels may indicate past rivers on other planets, specifically outflow channels on Mars and are theorised to exist on planets and moons in habitable zones of stars.
Read more about River: Topography, Classification, Uses, Ecosystem, Chemistry, Brackish Water, Flooding, Sediment Yield, Management, See Also
Famous quotes containing the word river:
“It is impossible to step into the same river twice.”
—Heraclitus (c. 535–475 B.C.)
“This ferry was as busy as a beaver dam, and all the world seemed anxious to get across the Merrimack River at this particular point, waiting to get set over,—children with their two cents done up in paper, jail-birds broke lose and constable with warrant, travelers from distant lands to distant lands, men and women to whom the Merrimack River was a bar.”
—Henry David Thoreau (1817–1862)
“It is ... despair at the mutability of all created things that links the Artist and the Ascetic—a desire to purify and preserve—to set oneself apart—somehow—from the river flowing onward to the grave.”
—Michele Murray (1933–1974)