Determinação dos regimes de precipitação, estação de cultivo e épocas de plantio no Estado da Paraíba.

Abstract

Using the annual distribution of weekly mean precipitation, obtained from the daily precipitation data with more than 30 years of observations for Paraíba state, five regi mes and twelve sub-regimes of precipitation were identified. These precipitation regimes are characterized by limiting re gions c1 ima to 1ogica 11y similar from the point of view of the temporal rain distribution. The precipitation mean curve for each regime was used for determining the so called "rainy" and "humid" seasons by the method of the percentages relatives to the most rainy week. Mean monthly temperatures, for these stations having precipitation data only, were estimated through a multi pie regression in which the temperature is a function of the local coordenates: latitude (Ø) , longitude (λ) and altitude (Z). The annual mean temperature was obtained as the arithmetic mean of the monthly mean values. These annual mean temperatures were used for estimating the corresponding daily values, em ploying the harmonic analysis method. The harmonic coefficients were estimated on the basis of the daily temperature data a_ vailable for five stations. The weekly potencial evapotranspira tion values were then estimated by the method proposed by THORNTHWAI TE & MATHER, 1955.