UPDATE TO THE RAINFALL EQUATION FOR BELÉM, PARÁ

Abstract

For the advancement of urbanization in a given area, particularly with regard to sanitation, an understanding of the interaction between the intensity, duration, and frequency of rainfall (IDF ratio) during heavy rains is essential. This is because the effective performance of drainage and stormwater management projects requires accurate data derived from this interaction, obtained through a rainfall equation. In this context, the objective of this study was to determine an updated rainfall equation for Belém, Pará. For this purpose, precipitation data from the Belém rain gauge station (code 148002) were used, as this station provided the most extensive data series, totaling 68 years of observations. For the disaggregation coefficients, the method of Taborga Torrico (1974), revised by Basso et al. (2016), was adopted; for the frequency distributions, the Log Pearson Type III function was used, as it best fit the data model; and finally, for determining the parameters of the rainfall equation (K, a, b, c), the linear regression method was used.