This study determines the degree of hydrological stress (HS) on the Goiana River basin in Pernambuco, a state in northeastern Brazil. The hydrological stress index is obtained by comparing the values of the surface permits with the limits granted by the managers. The results pointed to a situation of “High” hydrological stress (HS) in the Nazaré da Mata sub-basin, with approximately 94.76% of the grantable flow being used. In the Caricé sub-basin, the degree of hydrological stress was considered “Medium,” with about 31.77% of available flow being granted. The other sub-basins had results considered to be “Low” hydrological stress (between 0% and 25%). Given these results, this study emphasizes the importance of constantly monitoring data on the demand for water use in the region and improving the criteria management bodies follow when granting permits.

The objective of this study was to perform a sensitivity analysis and automatic calibration of the hydrological parameters of the Goiana river basin in the state of Pernambuco. A hydrological modeling structure for the basin was built using the PCSMMM (Personal Computer Storm Water Management Model) hydrodynamic model and the analyzes were carried out in 10 sub-basins. Based on the model developed for the basin, the resources available in the PCSWMM for sensitivity analysis and automatic calibration, known as SRTC (Sensitivity-based Radio Tuning Calibration), were explored initially to evaluate the most sensitive parameters and then to perform the calibration of basin parameters. The daily flow data were extracted in 5 fluviometrics stations present in the main water courses of the basin and the precipitation data in 10 pluviometric stations. The results of the simulations were analyzed for the following statistics: Integral Square Error (ISE), Nash-Sutcliffe Efficiency (NSE), Determination Coefficient (), in addition to the qualitative analysis of the hydrograph modeled in relation to the observations. The most sensitive parameters were the Curve Number (CN) and Manning's roughness for the permeable ones. In three control points (Engenho Retiro, Caricé and Nazaré) the SES values were 0.919, 0.899 and 0.884, respectively. The results, in general, indicate a very satisfactory performance of the tools of automatic calibration and sensitivity analysis of the model, besides being effective in relation to the traditional approaches of calibration by trial and error.