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Drainage Brazil is drained by three major river systems: the Parana-Paraguay-Plata in the south, the Sao Francisco River in the east, and the Amazon in the north. The highlands of southern Brazil are drained by the Parana River, Paraguay River, and Uruguay River, water from which flows eventually into the Plata. The Sao Francisco flows northward from the Brazilian Highlands for about 1,600 km (1,000 mi). Waterfalls and currents prohibit navigation in its lower course for about 322 km (200 mi). The Amazon River, the major river of South America, is the world's second longest (6,440 km/4,000 mi), and most of its basin lies within Brazil. No other river approaches its discharge or volume of flow: more than 198,100 m(3) (7,000,000 ft(3)) of water pass through its mouth into the Atlantic Ocean each second, more than ten times the volume of the Mississippi River. The river's channel reaches depths of 91 m (300 ft) in places, permitting oceangoing ships to navigate almost 1,600 km (1,000 mi) upstream. The Amazon's major tributaries are the Tocantins River, Araguaia River, the Madeira River, Rio Negro, the Xingu River, and the Tapajos. Resources Brazil's mineral resources are superlative, but many are still unexploited. Sizable deposits of iron and manganese ores have been discovered, but Brazil lacks the high-grade coking coal needed to transform them into steel. Brazil is a leading world exporter of iron ore. New discoveries of oil and increased domestic output permitted the country to reduce oil imports from over 58% of requirements in 1971 to 43% by 1991. Production of gold expanded markedly during the 1980s. Discoveries of other minerals--including phosphates, uranium, manganese, copper, coal, bauxite, platinum, and gemstones--are regularly made, particularly in the state of Minas Gerais and the Amazon area. more |
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