Caminhos da transposição do rio São Francisco in Hunza|Seabed Abysmal z35W7z4v9z8w

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April 17, 2017

Caminhos da transposição do rio São Francisco in Hunza




The São Francisco River or Rio São Francisco (Portuguese pronunciation: [sɐ̃w fɾɐ̃ˈsiʃku]) is a river in Brazil. With a length of 2,914 kilometres (1,811 mi),[1] it is the longest river that runs entirely in Brazilian territory, and the fourth longest in South America and overall in Brazil (after the Amazon, the Paraná and the Madeira). It used to be known as the Opara by the indigenous people before colonisation, and is today also known as Velho Chico ("Old Frank").[citation needed] The São Francisco originates in the Canastra mountain range in the central-western part of the state of Minas Gerais. It runs generally north in the states of Minas Gerais and Bahia, behind the coastal range, draining an area of over 630,000 square kilometres (240,000 sq mi), before turning east to form the border between Bahia on the right bank and the states of Pernambuco and Alagoas on the left one. After that, it forms the boundary between the states of Alagoas and Sergipe and washes into the Atlantic Ocean. In addition to the five states which the São Francisco directly traverses or borders, its drainage basin also includes tributaries from the state of Goiás and the Federal District. It is an important river for Brazil, called "the river of national integration" because it unites diverse climes and regions of the country, in particular the Southeast with the Northeast. It is navigable between the cities of Pirapora (Minas Gerais) and Juazeiro (Bahia), as well as between Piranhas (Alagoas) and the mouth on the ocean, but traditional passenger navigation has all but disappeared in recent years due to changes in the river flow (see below) More than 200 fish species are known from the São Francisco River basin and it is expected that several additional species will be discovered in the future, especially from the relatively poorly known upper parts of the river.[4] About 10% of the fish species known from the river basin are threatened and about 13% are important in fisheries.[5] About 64% of the fish species known from the basin are endemic,[4] including Conorhynchos conirostris (a catfish of uncertain taxonomic affinities),[6] Lophiosilurus alexandri (a flattened catfish),[4] Franciscodoras marmoratus (an armoured catfish),[4] Pygocentrus piraya (the largest species of piranha),[7] Orthospinus franciscensis (a characin and the only member of its genus),[4] and Salminus franciscanus (a relative of the golden dorado).[8] More than 40 annual killifish species are found in the São Francisco River basin, especially from the genera Cynolebias and Simpsonichthys.[4] Dams (preventing fish migrations on the river) and pollution do present a problem to the species in the river, and fish mass deaths have been recorded

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