Assessing the use of rainfall synthetic series to estimate rainfall erosivity in Brazil

Abstract

Although it has been used in research or technical work, applying synthetic rainfall data series to estimate rainfall erosivity is still a tool that requires careful evaluation and validation. In this study we evaluate the potential use of synthetic data sets to estimate the rainfall erosivity index (R-factor) in order to validate the use of this tool throughout Brazil. Sub-hourly rainfall data from 141 pluviographic stations were used. Pluviographic synthetic series were generated from ClimaBR software. A computer routine was specifically developed to identify erosive rainfalls. R-factor was calculated from erosive rainfall events and from pluviographic synthetic series, as well as through regression equations proposed in the literature. It was observed that the method estimating rainfall erosivity from synthetic pluviographic series (SS) had satisfactory performance and was superior to the use of data based on empirical equations (EE). The results indicate that applying ClimaBR synthetic pluviographic series to estimate rainfall erosivity is a valid and potentially applicable alternative. Moreover, its application in Brazil showed no needs for calibration. Due to these results, we believe that R-factors can be calculated for each pluviographic station in the country by using SS, creating a useful rainfall erosivity map with wide distribution throughout Brazil.