Paraná River, Basin, and Delta (South America)

Paraná River, Basin, and Delta (South America)

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The Paraná River is the second-longest river in South America. Running through Brazil, Paraguay, and Argentina, it becomes an alluvial basin before emptying into the Río de la Plata. The Paraná Delta consists of several islands known as the Islas del Paraná.

Paraná River

The Paraná River is the second-longest river in South America, after the Amazon River. It runs through Brazil, Paraguay, and Argentina for approximately 4,880 km (3,032 mi).

Forming at the confluence of the Paranaiba and Rio Grande rivers in southern Brazil, it flows in a general southerly direction until it joins the Uruguay River to form the Río de la Plata on the border between Argentina and Uruguay.

Its drainage basin, with an area of about 2,800,000 sq km (1,081,000 sq mi), includes the greater part of southeastern Brazil, Paraguay, southeastern Bolivia, and northern Argentina.

Upper and Lower Paraná

From its origin at the confluence of the Grande and Paranaíba Rivers to its junction with the Paraguay River, the river is known as the Alto (Upper) Paraná. This upper course has three important tributaries: the Tietê, the Paranapanema, and the Iguaçu, which have their sources near the Atlantic coast.

The Alto Paraná has two vegetation zones: forests to the east and savanna to the west. Forests continue along the Paraná downstream to Corrientes, where the savanna begins to dominate both banks. The river has a rich and varied animal life that includes many species of edible fish.

From its confluence with the Iguaçu River to its junction with the Paraguay River, the Alto Paraná continues as the frontier between Paraguay and Argentina. When the Paraguay River joins it, it becomes the lower Paraná and flows only through Argentine territory.

Among the many arms of the river are the Paraná Pavón, the Paraná Ibicuy, the Paraná de las Palmas, the Paraná Guazú, and the smaller Paraná Miní and Paraná Bravo.

The basin of the Alto Paraná has a hot and humid climate year-round, with dry winters and rainy summers. The climate of the middle and lower basins ranges from subtropical in the north to temperate and humid in the south, with less plentiful rainfall.

Map showing location of Paraná River

Map depicting the location of the Paraná River

Paraná River Basin

The Paraná River drainage basin, formed by the Paraná River and its tributaries, includes an area of approximately 2,800,000 sq km (1,081,000 sq mi) and the greater part of southeastern Brazil, Paraguay, southeastern Bolivia, and northern Argentina.

Up to the confluence with the Iguaçu River, its area includes Brazil's most industrialized and urbanized region, encompassing six Brazilian States and the Federal District. There are 57 large reservoirs in the basin.

It concentrates one-third of the Brazilian population in urban centers like São Paulo, the largest city in Latin America. Moreover, it is the drainage basin with the country's largest installed electricity generation capacity and the one meeting the highest demand.

Paraná Delta

The Paraná Delta consists of several islands known as the Islas del Paraná. The river flows north-south and becomes an alluvial basin (a flood plain) before emptying into the Río de la Plata.

It covers about 14,000 sq km (5,400 sq mi) and starts to form where the river splits into several arms, creating a network of islands and wetlands.

The delta is often divided into three parts:

  • the Upper Delta, from the Diamante-Puerto Gaboto line to Villa Constitución

  • the Middle Delta, from Villa Constitución to the Ibicuy Islands

  • the Lower Delta, from the Ibicuy Islands to the mouth of the river

The Lower Delta was the site of the first modern settlements in the Paraná-Plata basin and is today densely populated, being Argentina's agricultural and industrial core and host to several major ports.

The Predelta National Park, created in 1992, protects a sample of the Upper Delta. It is in the southwest of Entre Ríos, 6 km (4 mi) south of Diamante, and has an area of 24.58 sq km (9.49 sq mi), occupied by low-lying islands subject to flooding, as well as lagoons and swamps.

The Paraná Delta Biosphere Reserve comprises the second and third sections of the Islands of the San Fernando Delta, located just north of Buenos Aires. It was declared a natural reserve in 2000 by UNESCO.

Aerial view of Lower Paraná Delta

Aerial view of the Lower Paraná Delta