INVESTIGADORES
MARTIN Paula Beatriz
capítulos de libros
Título:
Monthly rainfall in Buenos Aires city (1861-2000) analysed using Gamma distribution function
Autor/es:
SERIO, L., AND MARTIN, P.
Libro:
Environmental Change and Rational Water Use
Editorial:
OrientaciĆ³n Grafica Editora
Referencias:
Lugar: Buenos Aires; Año: 2007; p. 367 - 376
Resumen:
The historical monthly rainfall record (1861-2000) of Buenos Aires City, Argentina, was analysed by fitting the Gamma distribution function. The whole record was shifted in 30-year periods, overlapped each 10 years. The shape and scale parameters of Gamma function were fitted to the observed monthly frequency distributions. We found a good agreement between theoretical and empirical distribution functions, as confirmed the non-parametric Kolmogorov-Smirnov test. In order to identify possible changes in precipitation regime, a trend analysis (Mann-Kendall test) was applied to the median (50-percentile) of monthly theoretical distribution. We found significant positive trends in summer months (4.1 mm/decade in January and 5.8 in February) and spring months (2.8 mm/decade in October and 2.5 in November).  The probability of extremely high monthly precipitation has increased too, as result of trend analysis applied to the 90-percentiles of gamma distributions. Its maximum increment has occurred to a mean reason of 7.8 mm/decade in January, although significant increments were found in other months during the warm season.  In addition to these changes in median and extreme monthly rainfall, we observed an increment in their interannual variability.