In hydrology, a mainstem (or trunk) is "the primary downstream segment of a river, as contrasted to its tributaries".[1][2] Water enters the mainstem from the river's drainage basin, the land area through which the mainstem and its tributaries flow.[3] A drainage basin may also be referred to as a watershed or catchment.[3]
The Mississippi River drainage basin with the mainstem highlighted in dark blue
Strahler diagram. Only a segment of the mainstem gets the highest number.
Hydrological classification systems assign numbers to tributaries and mainstems within a drainage basin. In the Strahler number, a modification of a system devised by Robert E. Horton in 1945, channels with no tributaries are called "first-order" streams. When two first-order streams meet, they are said to form a second-order stream; when two second-order streams meet, they form a third-order stream, and so on. In the Horton system, the entire mainstem of a drainage basin was assigned the highest number in that basin. However, in the Strahler system, adopted in 1957, only that part of the mainstem below the tributary of the next highest rank gets the highest number.[2]
In the United States, the Mississippi River mainstem achieves a Strahler number of 10, the highest in the nation. Eight rivers, including the Columbia River, reach 9. Streams with no tributaries, assigned the Strahler number 1, are most common. More than 1.5 million of these small streams, with average drainage basins of only 1 square mile (2.6 km2), have been identified in the United States alone.[2] Outside of the United States, the Amazon River reaches a Strahler number of 12, making it the highest-order river in the world.[4]
References
^Benke, Arthur C. & Cushing, Colbert E., eds. (2005). Rivers of North America. Burlington, Massachusetts: Elsevier Academic Press. p. 1137. ISBN0-12-088253-1.
^ abcPatrick, Ruth (1995). Rivers of the United States: Volume II: Chemical and Physical Characteristics. New York: John Wiley & Sons. pp. 15–17. ISBN0-471-10752-2.
^Briney, Amanda. "How Are the World's Waterways Classified?". ThoughtCo. Retrieved 2018-12-24.
April 30, 2023
main, stem, duke, ellington, single, main, stem, oliver, nelson, album, main, stem, album, hydrology, mainstem, trunk, primary, downstream, segment, river, contrasted, tributaries, water, enters, mainstem, from, river, drainage, basin, land, area, through, whi. For Duke Ellington s single see Main Stem For the Oliver Nelson album see Main Stem album In hydrology a mainstem or trunk is the primary downstream segment of a river as contrasted to its tributaries 1 2 Water enters the mainstem from the river s drainage basin the land area through which the mainstem and its tributaries flow 3 A drainage basin may also be referred to as a watershed or catchment 3 The Mississippi River drainage basin with the mainstem highlighted in dark blue Strahler diagram Only a segment of the mainstem gets the highest number Hydrological classification systems assign numbers to tributaries and mainstems within a drainage basin In the Strahler number a modification of a system devised by Robert E Horton in 1945 channels with no tributaries are called first order streams When two first order streams meet they are said to form a second order stream when two second order streams meet they form a third order stream and so on In the Horton system the entire mainstem of a drainage basin was assigned the highest number in that basin However in the Strahler system adopted in 1957 only that part of the mainstem below the tributary of the next highest rank gets the highest number 2 In the United States the Mississippi River mainstem achieves a Strahler number of 10 the highest in the nation Eight rivers including the Columbia River reach 9 Streams with no tributaries assigned the Strahler number 1 are most common More than 1 5 million of these small streams with average drainage basins of only 1 square mile 2 6 km2 have been identified in the United States alone 2 Outside of the United States the Amazon River reaches a Strahler number of 12 making it the highest order river in the world 4 References Edit Benke Arthur C amp Cushing Colbert E eds 2005 Rivers of North America Burlington Massachusetts Elsevier Academic Press p 1137 ISBN 0 12 088253 1 a b c Patrick Ruth 1995 Rivers of the United States Volume II Chemical and Physical Characteristics New York John Wiley amp Sons pp 15 17 ISBN 0 471 10752 2 a b Benke amp Cushing 2005 p 4 Briney Amanda How Are the World s Waterways Classified ThoughtCo Retrieved 2018 12 24 Retrieved from https en wikipedia org w index php title Main stem amp oldid 1080867655, wikipedia, wiki, book, books, library,
