Starting
from that date the Portuguese called Rio de Solis, Rio de
Plata
Since
1860, the republic name Argentina (of Latin - argentum "
- that means " silver ") is the official denomination
of the country.
The
fluvial system of the Prata basin, one of the largest of the
world, with a surface of 3.1000.000 Km2, that extends for
the territories of Argentina, Bolivia, Brazil, Paraguay and
Uruguay, formed by three great hydrographical units that are:
Rios Paraná, Paraguay and Uruguay, all with their sources
in Brazilian territory.
Rio
Paraná originates from Rios Paranaíba's confluence
and Rio Grande in the south of Minas Gerais, and it is the
most important hydrographical system of Rio Prata, due to
the magnitude
of its flow that is 12.480m3 a second, in the city of Posadas,
Argentina.
The length of its course is 3.740km. The superficies of its
basin is 1.510.000 Km2, unassuming Rio Paraguay's sub-basin.
The
whole upper River Paraná is in Brazil, making the frontier
between Brazil and Paraguay until its confluence with Rio
Iguaçu finally meeting with Rio Paraguay.
When
it joins Rio Paraguay its slope is very light, 0,36m/Km until
the mouth. Its width decreases from 4.200m in front of Corrientes
and to 2.000m in Rosário. The mouth is in a delta form,
with numerous arms, begins at 320Km in its outlet. The width
varies from 18 to 61Km, covering an area of 14.100Km2.