Simulação hidrológica e projeções das vazões mínimas do Rio Riachão, MG usando o modelo SWAT

Abstract

The Riachão River basin has a history of water scarcity and water use conflicts. With the intensification of agricultural projects, some environmental problems have emerged, highlighting the dispute by water use between agribusiness and family farming. In this context, the hydrological simulation of watersheds becomes a major tool for planning and management of water resources, including water availability prediction from global climate change. The objective was to evaluate the efficiency of the SWAT hydrologic model to simulate the stream flow of Riachão river basin, North of Minas Gerais State, Brazil, under the impact of alternative scenarios with the increase in mean surface air temperature. The SWAT model was adjusted for 1/1/2008 to 12/31/2014 period and calibrated with data measurement from the fluviometric station Station 14 Fernão Dias. The Nash-Sutcliffe efficiency (NSE) of 0.74 and 0.79 and percent bias (PBIAS) of 15.45 and 16.72% was found to calibration and validation period, respectively. The surface water availability in the hydrographic basin was calculated by Q9% stream flow, with calibrated value of 0.081 0.081 m² s¹. The scenarios of increase in mean air temperature (1.5, 2.0, 3.0, 4.0 and 5.0 °C) reduced Q9% by 7.66, 8.98, 10.49, 14.06 and 17.76%, respectively. This reduced surface water availability was assess based on water demand of the Riachão river and groundwater basin stress.