Abstract

GELMI, Mónica  and  SEOANE, Rafael. Temporal variation of extreme precipitations indexes in the centre of Buenos Aires province. Geoacta [online]. 2013, vol.38, n.1. ISSN 1852-7744.

The objective of this research is to study the temporal evolution of daily precipitation in order to detect the presence of trends and to estimate the frequency of extreme events. The observed precipitation series correspond to four meteorological stations located in the center of the Province of Buenos Aires, Argentina. Changes in daily extreme precipitation were assessed through the indices proposed by the World Meteorological Organization-Commission for Climatology (WMO-CCL) and the World Climate Research Program (WCRP) -Climate Variability and Predictability. In order to analyze possible changes in the return period - maximum precipitation relationship, two probability density functions were applied to the series, the Generalized Extreme Values and the two parameters Gamma. The obtained results show, in general, a higher probability of occurrence of greater precipitations over the period 1971-1999 respect of period 1951-1970. The rainfall events that caused floods in Olavarría and Azul since the '80s clearly show the interest of studying this subject, not only because of its social implications associated to floods, but the demand of developing techniques to update the estimation of design parameters of hydraulic works. The estimated indices suggest a positive trend in the precipitation at most of the analyzed meteorological stations and a higher frequency of occurrence of extreme values over the period 1971-1999 compared to the period 1951-1970.

Keywords : Precipitation Indices; Statistical Models; Extreme Events; Province of Buenos Aires.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )