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Posts tagged Pernambuco

Reservoirs on São Francisco River, Brazil

15.6S 47.8W

May 2nd, 2012 Category: Image of the day, Lakes, Rivers

Brazil - April 28th, 2012

Two large, artificial reservoirs can be observed along the São Francisco River, in northeastern Brazil. The river marks the border between the states of Bahia (below) and Pernambuco (above). At 3,160 kilometres long, it is the longest river located entirely within Brazil.

The lake to the left is known as the Sobradinho Reservoir. It measures approximately 320 km (200 mi) long, 4,214 km2 (1,627 sq mi) in surface area, and has a storage capacity of 34.1 km3 (8.2 cu mi) at its nominal elevation of 392.5 m (1,287.7 ft), making it the 12th-largest reservoir (artificial lake) in the world. Golden sediments color the lower half of the lake.

Sediments Framing Northern and Eastern Coastlines of Brazil’s Northeast Region

7.8S 39.7W

July 17th, 2011 Category: Sediments

Brazil - July 14th, 2011

This image shows part of the Northeast Region (Região Nordeste, in Portuguese) of Brazil, which is composed of the following states: Maranhão, Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe and Bahia, and it represents 18.26% of the Brazilian territory.

Geographically, the Northeast consists chiefly of an eroded continental craton with many low hills and small ranges. The highest peaks are around 1,850 metres (6,070 ft) in Bahia, while further north there are no peaks above 1,123 metres (3,684 ft).

On its northern and western side, the plateaus fall steadily to the coast and into the basin of the Tocantins River in Maranhão, but on the eastern side it falls off quite sharply to the coast except in the valley of the São Francisco river. The steep slopes and long cliffs of the eastern coastline are known as “The Great Escarpment”. Here, sediments frame the northern and eastern coastlines.

The escarpment serves an extremely important climatic function. Because for most of the year the Nordeste is out of reach of the Intertropical Convergence Zone, the easterly trade winds blow across the region, giving abundant rainfall to the coast but producing clear, dry conditions inland where the escarpment blocks moisture flow. This gives rise to four distinct regions, the zona da mata on the coast, the agreste on the escarpment, sertão beyond and the Mid north.

São Francisco River Between Bahia and Pernambuco States, Brazil

8.7S 38.9W

December 21st, 2009 Category: Rivers

Brazil - November 28th, 2009

Brazil - November 28th, 2009

The São Francisco River runs along part of the border between the Brazilian states of Bahia (below) and Pernambuco (above). The 3,160 kilometre-long river is the longest river located entirely within Brazil.

The segment of the river on the right side of the image appears much wider than that on the left side due to water held behind several dams. Four hydroelectric plants and dams are located along the river’s course: the Paulo Afonso Dam, Três Marias, Sobradinho and Luiz Gonzaga (Itaparica)

In addition to being used for hydroelectric power, in 2005, the Brazilian government proposed a controversial irrigation project called the “Transposition of the São Francisco” that would bring water from the river to semiarid areas of four Brazilian states.

Environmentalists argue that the project will do more harm than good, benefitting only large landowners and a very small population, while bringing considerable ecological impact. The government, on the other hand, insists that the project will give the people in the four states a much-needed water supply.

São Francisco River Behind Two Hydroelectric Plants, Brazil – December 5th, 2009

9S 38.2W

December 5th, 2009 Category: Image of the day, Rivers

Brazil - November 15th, 2009

Brazil - November 15th, 2009

Sun glint causes this segment of the São Francisco River, in Brazil, to appear a whitish-silvery color. With a length of 3,160 kilometres, it is the fourth largest river system in South America and the longest river wholly within Brazil. The section visible here marks the border between the states of Pernambuco (above), Bahia (below) and Alagoas (lower right).

This segment appears particularly wide due to several dams. The river’s hydroelectric potential started being harnessed in 1955, when the Paulo Afonso dam was built between Bahia and Alagoas. The Paulo Afonso plant now provides electric power for the whole of Northeastern Brazil.

Three other large hydroelectric plants were later built: Três Marias in Minas Gerais, built in 1961, Sobradinho in Bahia, built in 1977, and Luiz Gonzaga (Itaparica), between Bahia and Pernambuco, in 1988. Both the Paulo Afonso and Luiz Gonzaga (Itaparica) plants are located in the lower right part of the image.

Agriculture Near Sobradinho Lake, Brazil – May 19th, 2009

May 19th, 2009 Category: Image of the day, Lakes, Rivers

Sobradinho Lake, Brazil - May 11th, 2009

Sobradinho Lake, Brazil - May 11th, 2009

Sobradinho Lake lies in the São Francisco River Basin, in one of the most arid regions in Northeastern Brazil, within a land stretch categorized as the Lower-middle São Francisco, in the state of Pernambuco.

The dam, in its full capacity, consists of a lake of approximately 4,214 km2; 280 km in length, the width of which varies from 5 to 50 km, according to the Smithsonian Astrophysical Observatory. The dam storage capacity is that of 34.1 billion m3 of water.

Here, the lake appears  strikingly bright yellow-green due to sediments from the São Francisco River.

Being situated in a semi-arid region, the dam brought about significant development to local irrigated agriculture. Many fields can be seen east of the river in the full image.

The Caatinga ecosystem (xeric shrubland and thorn forest) has also, for that matter, undergone considerable changes. Stastical analysis of data collected before and after the filling of the lake showed that the dam has brought about considerable changes to regional meteorology, particularly concerning atmospheric humidity and wind speed.