Estimativa e mapeamento da chuva de projeto para instalações prediais na região oeste do Paraná

Abstract

The design rainfall is one of the fundamental parameters to the elaboration of rainwater buildings facilities projects. According to NBR 10844 it is recommended to obtain the rainfall intensity from historical series data from the project location. However, if there are no values in the place of interest, the Brazilian Standard suggests using a generic value equal to 150 mm/h to horizontal projection areas smaller than 100 m². For this, the aim of the present study was to apply the Generalized Extreme Values (GEV) distribution, through LH-moments method, to estimate intensity values to Western region of Paraná. Among the total of 64 rainfall stations studied, only one of them did not adjust to GEV. The quantiles with a return period of 1, 5 and 25 years were studied. Then, to obtain the 5 minutes duration rainfall intensity, it was applied the breakdown method to the daily precipitations. All the values obtained for the return period of 1 year were below the generic value suggested by the Brazilian Standard. For the other return periods, almost all the values are higher than the break point, ranging from 146,8 to 221,0 mm/h for a 5 years return period sample and from 199,2 to 313,6 mm/h for a 25 years return period sample. In addition, for the results presentation, two thematic maps were elaborated by the Ordinary Kriging method to represent the 5 minutes duration rainfall intensity with 5 and 25 years return periods.