SHP AUTÓDROMO (RS): A STUDY ON THE RELATIVE HUMIDITY OF THE AIR AROUND ITS WATER RESERVOIR

Abstract

Research on climate change in water reservoirs began in the early 20th century. The aim of this research was to evaluate the Relative Humidity conditions around the Autódromo SHP (Small Hydroelectric Plant), in Guaporé-RS, after the formation of its reservoir. ERA-5 reanalysis data were used, as well as rainfall data from the Guaporé Meteorological Station, provided by the National Water Agency (ANA in Portuguese). Statistical techniques (Pearson's correlation, Mean Absolute Error, Mean Relative Error, Root Mean Squared Error) were used to evaluate and validate the reanalysis data. Homogeneity tests (Student’s t test) were applied to data organized in two periods: pre-filling (2004-2011) and post-filling (2012-2019). Estimates of relative air humidity were obtained by correlating the Water Index (HI) with the Climatological Normal of Relative Humidity for Guaporé. The results showed that the reservoir had little influence on the dynamics of the analyzed variables. There was 4.4% increase in relative humidity in March and significant reduction in rainfall in November after the formation of the reservoir. Thus, it is believed that the changes in climatology observed around the reservoir are associated with macro-scale atmospheric dynamics, and not as a consequence of the formation of the reservoir.