Ajuste e validação de equações IDF a partir de dados pluviométricos para cidades do estado de Pernambuco, Brasil

Abstract

IDF equations are essential in the management, design, and operation of water systems and can be obtained through pluviograph data and pluviometric data. In this work, annual daily maximum precipitation data were collected from the National Water Agency (ANA) for 31 cities in the Sertão Pernambucano mesoregion. Initially, non-parametric hypothesis tests were applied to the data at a significance level of 5%. Then, the data were fitted to probability distributions, and the parameters of the IDF equations were determined by the isozone disaggregation method and logarithmic interpolation. The intensities calculated by the isozone method and the intensities calculated by the adjusted IDF equation were compared by the efficiency coefficients (NSE) and the percentage standard error (EPE) to evaluate the adjustment of the parameters. Finally, the intensities of IDF equations for pluviometric and pluviographic data were compared using statistical indices for some cities. The results revealed that EPE ranged from 2% to 7%, NSE was above 0.98, and the statistical indices showed a great performance. Therefore, the disaggregation methodology used is a viable alternative for fitting IDF equations in the studied region.