chapter - Atmospheric and Oceanic Science

Physiography and Hydrology
right bank, for what the very high discharges cause severe floods. Because of the
scarce contributions from Paraguay River, these floods are generally product of the
climatic forcings in the Upper sub-basin of the Paraná River.
As shown in Figure 4.2, up to the Itaipu Dam, the Paraná River presents
marked seasonality, accompanying the Brazil Southeasterly climate regime. The
streamflows at Posadas indicate a reduction in the annual range due to the different
hydrological regime of the Iguazu. In Corrientes, the Paraná receives the contribution
of the Paraguay River, significantly increasing its flow, mainly in June-July,
when the Paraguay River presents the largest volumes.
Table 4.3 presents some characteristics of the main tributaries of the Paraná River,
with the exception of the Paraguay River that is approached independently hereinafter.
Fig. 4.2. Mean monthly flows of the Paraná River at different stations along the main course.
[National Operator of the System-Brazil WWWeb, ANA WWWeb, Mining of the Argentine Republic, WWWeb]
Table 4.3. Features of the main tributaries of the Paraná River.
River Station
49
Drainage Area Annual mean
(km 2 ) volume (m 3 /seg)
Paranaíba São Simão 181040 2347
Grande Água Vermelha 139900 2069
Tietê Três Irmãos 71510 788
Paranapanema Rosana 99000 1278
Iguazú Salto Caxias 57974 1320
[Operador Nacional do Sistema-Brasil WWWeb, ANA WWWeb]