Performance de modelo climático de previsão da precipitação pluviométrica no Estado da Paraíba.

Abstract

A methodology for forescating the acumulatcd rainfall (AR) in differcnt locations and mesoregions of Paraíba State, based on a model proposcd by Silva (1985,1988), was the objective of this study. A network of 72 rain stations, associated with three mesoregions of Paraíba State, were used. For each State mesoregion (Eastcrn, Central and Western) a rainy scason (RS) was established, with different subdivisions of them. The Beta probability distribution model was ajusted to lhe ratio betwccn lhe AR of the First period of the RS (Xi) and the total AR of the rainy season. That probabilislic model was used in the determination of statistical parameters (first - Ql and forth - Q4 quintis) and the probability of oceurrence of AR, in the second period of the RS, greater than the average of that same period, for each selected location. It was observed that in 1999 and 2000 therc were a great number of accumulated rainfall greater than the average of the second period (Yi) of the RS, for each of selected stations. The index of success, for the AR forecasted in those years, was greater than 80%, except for the RS denominated of EC8 in 2000. In 1998, considered a very dry year, the success index for oceurrence of the minimun AR was less than the expected valuc. Na important conclusion in that, the methodology presented is appropriated and seems to be am important tool for forecasting the oceurrence of drought in Paraíba State.