ABSTRACT:
The aim of this study was to determine the sample size, in number of years, to estimate the means monthly rainfall in locations of Mato Grosso do Sul and verify its spacetemporal variability. It was used the rainfall data for the period 1954-2013, collected from the Hydrological Information System of the National Water Agency - ANA. The means and standard deviation were calculated for each of the 384 time series (12 months x 32 locations) and the aleatory and normality data were tested. Then it was verified the homogeneity of variance among months in each locality and among locality in each month and it was determined the sample size to estimate the means monthly rainfall in each month and locality. The sample size (number of years) to estimate the means monthly rainfall is dependent on the month and locality. One concluded that 63 years of data are enough to predict the average monthly rainfall, with an estimation error equal to 45% of estimated average, with a degree confidence of 95%.
Key words:
time series; error of estimation; sampling
) de precipitação pluvial mensal, em cada mês e local do Estado do Mato Grosso do Sul.
