Tributary
Encyclopedia
A tributary or affluent is a stream
Stream
A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...

 or river
River
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 before reaching another body of water. Small rivers may also be called by several other names, including...

 that flows into a main stem
Main Stem
"Main Stem" is 1942 instrumental by Duke Ellington and His Famous Orchestra. Although recorded in 1942, the single would not be released until 1944 where it was Duke Ellington's last of four number one's on the Harlem Hit Parade. "Main Stem" would also peak at number twenty on the pop chart"Main...

 (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the mainstem river serve to drain the surrounding drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 of its surface water and groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...

 by leading the water out into an ocean or sea.

A confluence
Confluence
Confluence, in geography, describes the meeting of two or more bodies of water.Confluence may also refer to:* Confluence , a property of term rewriting systems...

, where two or more bodies of water
Bodies of Water
Bodies of Water is a band from the Highland Park neighborhood of Los Angeles, California, signed to independent record label Secretly Canadian. The core group consists of married couple David and Meredith Metcalf. However, the band often plays LA shows with five or more additional musicians, such...

 meet together, usually refers to the joining of tributaries.

Reciprocal to a tributary is a distributary
Distributary
A distributary, or a distributary channel, is a stream that branches off and flows away from a main stream channel. They are a common feature of river deltas. The phenomenon is known as river bifurcation. The opposite of a distributary is a tributary...

, a river that branches off of and flows away from the main stream. Distributaries are most often found in river delta
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...

s.

Terminology

'Right tributary' and 'left tributary' (or 'right-bank tributary' and 'left-bank tributary') are terms stating the position of the tributary relative to the flow of the mainstem river. These terms are defined from the perspective of looking downstream (in the direction the water current
Current (stream)
A current, in a river or stream, is the flow of water influenced by gravity as the water moves downhill to reduce its potential energy. The current varies spatially as well as temporally within the stream, dependent upon the flow volume of water, stream gradient, and channel geometrics...

 is going).

Ordering and enumeration

In geography
Geography
Geography is the science that studies the lands, features, inhabitants, and phenomena of Earth. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes...

, tributaries are sometimes ordered from those nearest to the source of the river
Source (river or stream)
The source or headwaters of a river or stream is the place from which the water in the river or stream originates.-Definition:There is no universally agreed upon definition for determining a stream's source...

 to those nearest to the mouth of the river
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...

. For example, the Strahler Stream Order
Strahler Stream Order
In mathematics, the Strahler number or Horton–Strahler number of a mathematical tree is a numerical measure of its branching complexity....

 examines the arrangement of tributaries in a hierarchy
Hierarchy
A hierarchy is an arrangement of items in which the items are represented as being "above," "below," or "at the same level as" one another...

 of first, second, third, and higher orders, with the first order tributary being typically the least in size. For example, a second order tributary would be composed of two or more first order tributaries combining to form the second order tributary.

Another method is to organize tributaries from mouth to source, in the form of a tree structure
Tree structure
A tree structure is a way of representing the hierarchical nature of a structure in a graphical form. It is named a "tree structure" because the classic representation resembles a tree, even though the chart is generally upside down compared to an actual tree, with the "root" at the top and the...

, stored as a tree
Tree (data structure)
In computer science, a tree is a widely-used data structure that emulates a hierarchical tree structure with a set of linked nodes.Mathematically, it is an ordered directed tree, more specifically an arborescence: an acyclic connected graph where each node has zero or more children nodes and at...

 data structure
Data structure
In computer science, a data structure is a particular way of storing and organizing data in a computer so that it can be used efficiently.Different kinds of data structures are suited to different kinds of applications, and some are highly specialized to specific tasks...

.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK