Precipitation data analysis aiming the design of rainwater capture and storage systems

Abstract

In the rainwater capture and storage project, a lot of information about rainfall is needed. This paper aims to describe and exemplify the main analyzes that can be carried out with the observed rainfall series and its applications in the sizing of the system. The daily precipitation data series from 1974 to 2019 from Chapecó, SC, was used. It has been shown that monthly and annual precipitation can be used to estimate the volume of usable water. However it is recommended to use precipitation values ​​associated with probability levels. The analysis of maximum annual rainfall is used in the dimensioning of gutters and conductors. For Chapecó, the maximum rainfall intensity lasting 5 minutes and a return period of 5 years, used in the dimensioning of the gutters, is 183.8mm h^-1. Determining the duration of dry periods allows dimensioning the volume of the reservoir. For Chapecó, the duration of the consecutive period without rain (P < 2.0mm) with a return period of 5 years is 25.7 days.