Hydrological simulation in a basin of typical tropical climate and soil using the SWAT model part I: Calibration and validation tests

Study region: The study was developed for fhe Pomba River Basin, which is located in southeast region of Brazil in the continent of South America. Study focus: This study aimed to (a) calibrate and validate the SWAT model for a sub-basin of Pomba River Basin, (b) validate it for use with upstream and downstream control sections and (c) validate it for sub-basins other than the one where calibration was performed. This was done with the goal of having a model that can be used for the estimation of water availability and the planning of soil use and occupation. The model was calibrated by trial and error during the period from January 1996 through December 1999, while validation was conducted during the period from January 2000 through December 2004. Estimated the maximum, average and minimum annual daily streamflows were evaluated based on the paired t-test and linear regression analysis. New hydrological insights: The SWAT model was qualified for simulating the Pomba River sub-basin in the sites where rainfall representation was reasonable to good. The model can be used in the simulation of maximum, average and minimum annual daily streamflow based on the paired t-test, contributing with the water resources management of region, although the model still needs to be improved, mainly in the representativeness of rainfall, to give better estimates of extreme values.