Stationarity in annual daily maximum streamflow series in the upper Juruá River, western Amazon

Abstract

The objective of this study was to investigate the hypothesis of stationary behavior in the streamflow regime of the upper Juruá river. For this purpose, annual maximum daily flow data recorded at stations located in Cruzeiro do Sul and Marechal Thaumaturgo, AC, Brazil, were analyzed using Mann-Kendall, Pettitt, and Spearman’s Rho tests. The results show sufficient evidence to conclude that in Cruzeiro do Sul flow rates have an ascending temporal behavior, while in Marechal Thaumaturgo it is descending. However, this tendency is not significant (p<0.05), allowing to conclude in favor of the hypothesis of stationarity in the streamflow series of the referred basin. Thus, one of the physical implications associated to the results obtained may be the conclusion that the streamflow regime in the Upper Juruá basin has not changed significantly over time.