Modelagem hidrológica em uma sub-bacia hidrográfica do Baixo Rio Araguaia, TO

Abstract

Hydrological simulation is an important tool for water resources management since it allows for practitioners to evaluate the impacts of anthropic activities and climatic changes on water availability. The Lontra River watershed is situated in the Lower Araguaia River Basin which is an important economic region of Northern Tocantins State. The understanding of its hydrological features is fundamental for the development of environmental studies for supporting the decision-making related to the water resources management as strong pressure has been observed due to both the agricultural frontier expansion and installed economic center. The LASH hydrological model (stands for Lavras Simulation of Hydrology) is characterized as a deterministic, semi conceptual and spatially distributed model and has been successfully applied in watersheds located in Southeastern Brazil. It was found in this study that the model was able to adequately capture the overall hydrological regime in the studied watershed. Three statistical coefficients used for measuring the model goodness-of-fit, Nash-Sutcliffe (CNS), Log (CNS) and determination coefficient (R²), have shown values greater than 0.74, 0.80 and 0.90, respectively. The simulated flow duration curve presented a good fit in relation to the observed one, with small errors for prediction of minimum and maximum stream flows. Thus, we can be conclude that LASH model simulated properly the hydrological regime in the Lontra River Watershed and it can be applied for either evaluation water availability or planning and management of water resources in the Lower Araguaia River Basin.