STATIONARITY IN ANNUAL DAILY MAXIMUM STREAMFLOW SERIES IN THE HYDROGRAPHIC BASIN OF THE UPPER JURUÁ RIVER, WESTERN AMAZON

The present study has the objective of investigating the hypothesis of stationary behavior in the streamflow regime of the upper Jurua river basin. For this purpose, the annual maximum daily flow data recorded at stations located in Cruzeiro do Sul and Marechal Thaumaturgo, AC, Brazil, were analyzed using the Mann-Kendall, Pettitt, and Spearman’s Rho tests. The results show sufficient evidence to conclude that, in Cruzeiro do Sul, the flow rates present 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 stationarity hypothesis 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 Jurua basin has not changed significantly over time.