ENSO Impacts over Northeastern Argentina

The Northeast of Argentina is frequently affected by floods of the Paraná River due to precipitations in Brazil and/or inland floods produced by local precipitations. About 70% of the country's total population lives in this area -the most productive of Argentina- and the socio-economic impact of some extreme events has been disastrous.

Droughts with similar characteristics of occurrence also affect the region, going from one extreme to the other in a short time, and thus generating completely different emergency situations, all of them equally serious.

The present work analyses extreme climatic situations, both of the Paraná River and the Northeast of Argentina, relating them to the development of surface temperature in the Equatorial Pacific Ocean (EL NIÑO, LA NIÑA and neuter years). It was found, as expected, that most of the strong and very strong EL NIÑO events were associated to extraordinary floods in the Paraná River; though some floods were associated to the neuter phase (1959). LA NIÑA phase (cold events) was not always associated to important drops of river water levels.

The precipitation behaviour over the region was varied, and it did not always statistically coincide with the expectation (E.g.: 1959-1983)

EL NIÑO events were individually analysed, and their effects were predicted by statistical models. The forecasts turned out to be right both in the river and the region.