| The Sao Francisco river | |
| River | |
 |
|
| Country |  Brazil |
|---|---|
| Region | South America |
| Length | 2,830 km (1,758 mi) |
The Rio São Francisco, also known as The Opara, by the indigenous people before colonisation, or popularly Velho Chico (Old Frank), originates in the state of Minas Gerais. It runs generally north behind the coastal range draining an area of over 630,000 km2 before turning east to form the border between the state of Bahia on the one hand, and the states of Pernambuco and Alagoas on the other. and before entering the Atlantic Ocean between the states of Alagoas and Sergipe. She has a length of 2830 km, ranking fourth in length among the South American rivers (third in Brazil). It is an important river for Brazil, it is The river of national integration; A river that unites diverse climes and regions of the country. In particular it links the South_East with the Mid_West and the North_East
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Discovery
The Rio São Francisco was discovered on 4 October 1501 by the Florentine discoverer Amerigo Vespucci, who named her after Saint Franciscus of Assisi, who’s feast day falls on 4 October. It is the longest river running completely in Brazil.
The four parts of the Rio São Francisco
The full length of the river, that runs through five states, may be divided into four parts as follows:
- The high part of the Rio São Francisco, from its origin to Pirapora in Minas Gerais.
- The middle part, from Pirapora MG , where the navigable part begins, up to Romanso in Bahia and ending in the Sobradinho dam, BA
- The lower middle part, from Romanso to Paulo Alfonso , also in Bahia and ending with the Itaparica dam.
- The low part, from Paulo Alfonso till its mouth in the Atlantic Ocean
Tributaries
The river obtains water from 168 rivers and streams,0f which 99 always flow, 90 on the right and 78 on the left. The main tributaries are the:
- The Paraopeba River,
- The Abaeté River,
- The das Velhas River,
- The Jequitaí River,
- The Paracatu River,
- The Urucuia River,
- The Verde Grande River,
- The Carinhanha River,
- The Corrente River, and
- The Grande River.
The states that are linked
The river runs through the following five states:
- Minas Gerais,
- Bahia
- Pernambuco
- Sergipe
- Alagoas
The hydrographic basin also consists partly of the states Goias and the Federal district of Brazilia
Navigability
The Sao Francisco river is naturally navigable between Pirapora in MG and the twin cities Petrolina in PE and Juazeiro in BA all through the year with variations in depth depending on the rainfall. Because of the diversity of the physical characteristics over the length of thIs navigable stretch It may subdivided in three substretches as follows:
- PiraporaMG till Pilao-ArcadoVelho BA with a lenghth of 1015 km, differences in hight up to 6 m may occur due to rains and drought.
- Pilao-ArcadoVelho BA till the Sobradinho dam, this lake has a length of 314 km, surface area 4214 km2, with comfortable depth.
- From the Sobrdinho dam till the twin cities Petrolina/Juazeiro, with a length of 42 km and a depth of 2 m, sustained by a flow of 1500m3/sec.
Towns and population
The area crossed by the river is vast and sparsely populated, but several towns lie on the river. Beginning in Minas Gerais the river passes by Pirapora, São Francisco, Januária, Bom Jesus da Lapa, the twin cities of Petrolina and Juazeiro, and Paulo Afonso. The hinterland is dry and under populated so most of the towns are small and isolated. Only Petrolina and Juazeiro have grown into medium sized cities and are important because of the fruit production based on irrigation from the Sobradinho dam.
Some history
The Velho Chico (Old Frank) had been navigable until recent years by a type of boat called gaiolas (cages). These were paddle-wheel steamboats dating from the time of the American Civil War.
This water route is always open in the stretch between the cities of Pirapora (Minas Gerais) and Juazeiro (Bahia) or Petrolina (Pernambuco), the last two cities lying across from each other. This was a distance of 1,371 km.
With the coming of the-artificial lake of Sobradinho in Bahia, the conditions of navigability were altered considerably, since the great size of the lake allowed for the formation of short waves of considerable height, similar to those in the ocean.
In a short time the navigation of the gaiolas became impossible because they could not cross the Sobradinho lake. The shells of these old river boats can still be seen on the river at Pirapora.
Hydro electric dams
Until the building of the hydroelectric dams at Paulo Afonso in 1955 the entire river was a major route of commerce and entry into the hinterland of the northeast region. Paulo Afonso's hydroelectric plant now provides electric power for the entire northeast. In addition to the Paulo Afonso hydroelectric plant there are two other major plants and reservoirs on the São Francisco. The second major hydroelectric plant was built at Tres Marias in Minas Gerais in 1961 creating a reservoir of 1040 square kilometers. In 1977 40 km from Petrolina (Pernambuco) and Juazeiro (Bahia) the Sobradinho dam was completed forming at the time the largest artificial lake in the world with an area of 4,214 square kilometers.
Importance and the Future
The São Francisco has great importance in history and particularly in folklore. That history is celebrated in song, legend and souvenirs based on the carranca that once kept river demons from São Francisco boats. Tourist shops far from the river have modernized versions of these vanishing originals. The stories of river demons and monsters persist today.
From Paulo Afonso to the historic town of Penedo, Alagoas the river lies at the bottom of a gorge or steep sided valley. Piranhas, a town up river, was once to be the terminus of a railroad. The town has a number of buildings built during this period and later abandoned. They have been restored and are emerging as a tourist attraction.
In 2005, the Brazilian government proposed an irrigation project that would bring water from the river to four Brazilian states. Environmentalists argue that the project will do more harm than good while the government insists that the project will give the people in the four states the much needed water supply.
External links
- [1]
- Main Brazilian Hydrographic Basins (Map and brief description.)
- Detailed Basin map (in Portuguese)
- O Rio São Francisco e seus numeros
- Galeria de imagens
- Google, Apresentacao.pps Sao Fransico, a beautiful presentation met clearly the parts of the river.
- IPH_Sumario.pps
- http://www.oas.org/dsd/Events/english/Documents/OSDE_4SaoFrancisco.pdf
Coordinates: 13°10′33″S 43°25′05″W / 13.17577°S 43.41797°W
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