Resumen

BLANCO, Andrés; BARBOZA, Jesús  y  RODRIGUEZ, Jorge. Rain Annual Rate Regime of a set of Venezuelan Rainfall Stations, Based on Fourier Analysis, and the Analysis of Group. Terra [online]. 2010, vol.26, n.39, pp.31-57. ISSN 1012-7089.

To describe the climate regime of intra-annual precipitation, generally identified lapses greater and less than the arithmetic mean of the 12 monthly values and extreme rainfall amounts. This paper aims to set the variation of rainfall in the year by applying Fourier analysis to the climate record, covering the period 1961-1990, 15 rainfall stations distributed over the national territory, and then combined into groups internally homogeneous but externally heterogeneous using automatic clustering technique (Cluster Analysis). Obtaining the Fourier coefficients by multiple regression, generated a matrix of 15 cases for 6 values associated with three cycles of harmonic curves, which at least explained in more 90% of the variability of monthly rainfall. In this way were seven groups, namely: (1) Barcelona, Ciudad Bolívar, Maturín, San Fernando de Apure, which are characterized by a unimodal rainfall regime with a peak in july-August (2) Barquisimento, Santa Elena de Uairén, with maximum in june and october secondary, (3) Colonia Tovar, Maracaibo, Maracay, Mene Grande peaks in september-october and another secondary maximum in may-june (4) Coro, Maiquetía with a rain which increased from february and march until the end of the year (5) Merida presents a bimodal peaks in may and in october with minimal side july (6) Puerto Ayacucho with unimodal rainfall regime with maximum in june and far above the minimum of 30 mm and (7) San Antonio del Tachira has a bimodal peaks in april and october and lower secondary which covers the months of july and august. Comparing these results with the automatic grouping respective pluviogramas was found that the representation by means of Fourier coefficients was properly concluded that it may be suggested as a choice to include the status of annual rainfall variability.

Palabras clave : Rain; Climate; Regime; Fourier Analysis; Cluster Analysis; Venezuela.