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:
“If a walker is indeed an individualist there is nowhere he can’t go at dawn and not many places he can’t go at noon. But just as it demeans life to live alongside a great river you can no longer swim in or drink from, to be crowded into safer areas and hours takes much of the gloss off walking—one sport you shouldn’t have to reserve a time and a court for.”
—Edward Hoagland (b. 1932)
“It is impossible to step into the same river twice.”
—Heraclitus (c. 535–475 B.C.)
“We approached the Indian Island through the narrow strait called “Cook.” He said, “I ‘xpect we take in some water there, river so high,—never see it so high at this season. Very rough water there, but short; swamp steamboat once. Don’t paddle till I tell you, then you paddle right along.” It was a very short rapid. When we were in the midst of it he shouted “paddle,” and we shot through without taking in a drop.”
—Henry David Thoreau (1817–1862)