PIAU

estado (state) of northeastern Brazil, bordered by the states of Cear, Pernambuco, and Bahia, by a very small part of Tocantins on the east and south, and by Maranho on the west and north. Covering less than 3 percent of Brazil's total area, it has an area of 96,886 square miles (250,934 square km). The state capital is Teresina, located at the confluence of the Parnaba and Poti rivers. The state has a small Atlantic coastline of about 40 miles (64 km). The settlement of Piau in the 17th century came with the expansion of cattle ranching in the backlands of the interior, setting that area apart from the sugarcane agriculture of the coastal lowlands. The settlers arrived from the east, moving up the valley of the So Francisco River in Pernambuco and onward in a westward direction into Piau. One of their leaders was Francisco Dias d'Avilla, who fought bloody battles with the Indians. Piau was a part of the captaincy of Maranho from 1718 until 1811, at which time Piau became a separate administrative unit. The Parnaba River runs along the western boundary of the state, linking the Atlantic port of Parnaba with the inland cities of Teresina and Floriano. As one moves away from the river and the coastal area toward the south and east, the land rises gradually in a series of plateaus edged by cliffs. On the border of the state of Cear, the plateau is broken by a gap through which the Poti River runs. Temperatures show little variation, averaging about 79 F (26 C) in the northern part of the state and a few degrees less in some of the higher elevations in the south. Annual rainfall is about 59 inches (1,500 mm) in the north, but, in the drier east and southeast, it averages about 20 inches (500 mm) a year. The dry months are in winter and spring. The vegetation of the south and east is that of Brazil's semiarid northeastern backlands: a thorny, deciduous scrub woodland known as caatinga. This gives way in the north to deciduous forests interspersed with areas of palms and cocoa trees. Babassu palm (Orbignya speciosa). Piau is sparsely populated. Most of its inhabitants are of mixed Indian and European ancestry, although blacks are found in the northeastern coastal zones, where the colonial sugar plantations once employed many African slaves. The largest city is Teresina, the capital. Other towns include Parnaba, Floriano, Campo Maior, Picos, and Oeiras. The principal economic activities are the raising of livestock and the production of palm seeds, palm oil, and palm wax from the carnauba and babassu palm trees (see photograph). Standards of living in Piau are among the lowest in Brazil. Infant mortality rates are very high, largely because of infectious and parasitic diseases. Hospital clinics reach about one-quarter of the population. The national government, however, is engaged in programs to control malaria and other endemic diseases. Piau had a few thousand primary schools in the late 20th century with a few hundred thousand students. In the lower-level secondary schools there were several thousand students. The state also had newspapers, radio stations, one theatre, and numerous cinemas. Piau is a somewhat isolated state, lacking good communications even with neighbouring states of the northeast. Teresina has rail connections across the state of Maranho on the west to the port of So Luis; another railroad runs from Teresina northward through Campo Maior to the state's port of Lus Correia. One good all-weather federal highway runs from Teresina northeastward to Sobral in the state of Cear. Several important new highways were under construction in the late 20th century by the federal government, including one from Teresina to Picos, another from Fortaleza in Cear to Picos and southward toward Braslia, and an east-west trans-Amazonian road that will pass through Picos. Pop. (1990 est.) 2,666,100.