Identificação de regiões pluviometricamente homogêneas segundo um método de classificação automática.

Abstract

It were analyzed annuals , haIf-yearIies and quaterlies pluviometricaI means from 400 stations that covered a continuous área formed by the states Piauí, Ceará , Rio Grande do Norte , Paraíba , Pernambuco, Alagoas and Sergipe . These stations showed recording data from thirty years over a range from 1937 to 1973. In order to identify regions PIuviometricaIIy homogeneous it were utilized a partition technique for the Cluster Analysis d enominated Kmeans Method and a method which is based on the within the groups inertia for the formation and definition of the number of groups, respectiveIy . In this way it were identified twenty eight groups of stations related to the annual mean, twenty related to the haIf-yearIies means and twenty related to the quaterlies means. It was then evaluated the applicability of the above mentioned methods to the three types of analyzed means by comparing the results with regional studies based on conventional methods. With the objective for verifying the possibility to use this purpose in the pluvial regtonaIization these methods were also applied to the monthlies means obtained from Paraíba States stations. It was then verified that the Kmeans Method is applicable to those means in the mentioned regionaIization but, in this case , it is necessary a predifinition of the e number of groups. Finally, it was verified that the utilized methods cannot be applied to the referred variables yet related to the pluvial regionalization marking an exception of a partial Kmeans appIicabiIity to quaterlies means.