Análise de variancias pluviométricas na bacia hidrográfica do rio Tabo?o - RS

摘要

The objective of this paper was to determine the probabilistic distribution that fits the variance of the precipitation data obtained in six stations located at Tabo?o river watershed, northwestern region of Rio Grande do Sul State, during a seven years period from 5/May/2003 to 9/May/2006 and from 1/July/2007 to 4/June/2011. Group patterns were determined in relation to the variance. The Shapiro-Wilk test was used for a comparison between the observed and theoretical distributions of the variance. After determining the Log Pearson and Gama distribution, the grouping of stations was performed based on theirs variances by the Euclidean distance using the Ward's method. The evaluation with the ANOVA and Tukey's test showed that the proposed groupings were not sustainable, which implies the homogeneity among the mean values of the historical series variances from the six analyzed precipitation stations. The obtained results permit to conclude that the precipitation is homogeneous in the Tabo?o river watershed.