Aplicação de modelos hidrológicos determinístico e estocástico mensais na bacia hidrográfica do Xingu - Pará.

Abstract

The hydrological modeling is an important tool in the water resources programs planning and management of river basins. ln general the hydrologic forecast can be made by means of two types of models: deterministic models and stochastic mode-ls, ln this work, it was applied a monthly detenninistic hydrologic model of two parameters developed by Xiong and Guo (1999) and a stochastic model, denominated ARlMA “Auto Regressive IntegratedMoving .Average“. whose methodology was developed by Box and Jenkins (1976), to simulate the monthly runoff of the river basin of the Xingu in Para statel who occupies an area approximately of 314,427 km2, corresponding to 25.1% of the state area. The main objective of this work was to simulate the monthly runoff through the models and to compare its results; and to analyze specifically the influence of phenomenon ENSO - El Nino / South ()scillation, in the observed runoff of the basin through of the analyzed annual hydrological response for each station located in the basin. The hydrologic model deterministie applied possess & simple structure and presented good results. however it revealed very sensible the extreme precipitation events. The stochastic model ARlMA. it efficient to capture the dynamic of the temporal series, presenting very satisfactory results in the simulation of the monthly runoff in the basin stations. Both models should be applied with caution in the rainy period, where extreme precipitation events occur and consequently peak runolT, It also was verified that years of La Nina (El Nino) the annual hydrological response of the basin stations presented with larger frequency values lesser (larger) that the observed climatologieal average.