Extreme Droughts in La Plata Basin. The Climate of the Region is Going Drier?

RIVERA, J A PENALBA, O C

Foz de Iguazu

Congreso; The Meeting of the Americas. AGU 2010; 2010

AGU

During the second half of the twentieth century, a positive trend in annualprecipitation was observed in Southeastern South America. Instrumental andhistorical records of Pampean lakes (from 28° to 38°S) show that long dryintervals characterized the first 75 years of the 20th century, whereas positivehydrological balances have occurred after the 1970s. This annual precipitationincrease might be accompanied by greater interannual variability inprecipitation, which could increase the risk of droughts and their consequentnegative impacts. The aim of this paper is to analyze the spatio-temporalvariability of droughts in La Plata Basin (LPB) and to determine the occurrenceof the most extreme drought on record from a precipitation standpoint alone.We used historical records of daily rainfall stations distributed along LPB, whichin some cases begin during the first decades of the twentieth century.