River bifurcation

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River bifurcation (from Latin furca, fork) is the separation of a stream into two parts. The creation of distributaries are the consequences of bifurcation.

[edit] Bifurcation ratio

One quantitative measure of a drainage basin is the bifurcation ratio. Robert E. Horton was the first to come up with this concept, when he created the "laws of drainage composition" and the "law of stream number." This law stated that there is a hierarchy of streams ranked by order. The first order streams are the individual streams starting from the water sources. First order streams merge to form second order streams, and second order streams form third order streams.

The ratio is calculated by dividing the number of first order streams by the number of second order streams, then dividing the second order streams by the next highest order, and so on. The average of all these ratios gives the bifurcation ratio.

If the bifurcation ratio is low, there is a higher chance of flooding, as the water will be concentrated in one channel rather than spread out, as a high bifurcation ratio would indicate. The bifurcation ratio can also show which parts of a drainage basin is more likely to flood, comparatively, by looking at the separate ratios. Most British rivers have a bifurcation ratio of between 3 and 5. ^[1]

One of the most famous bifurcations is the Casiquiare canal that links the Orinoco River with the Amazon.

A second river bifurcation is in Serbia, Europe in the Nerodimka River. The Nerodime Bifurcation represents a hydrological curiosity. With the bifurcation of Nerodimka river waters are downloaded in the Aegean and Black sea. This way an interesting phenomena with an educational importance is created. The Bifurcation is located in the southern part of the Kosovo territory of Uroševac Municipality. The Bifurcation of Nerodimka is the very first hydrological protected object in Serbia (1979). The Nerodimka Bifurcation is declared as a strict wildlife sanctuary, I category according to (IUCN). The protected compound is laid on a surface of 13,0 ha. It is considered that the bifurcation is an artificial phenomena, but under extremely favorable natural conditions for the creation of which no emphasized technical measures were undertaken.