Avaliação da resposta da vazão às mudanças climáticas na bacia do reservatório de Nova Ponte, Alto Rio Araguari/MG

Abstract

The Nova Ponte Hydroelectric reservoir is the first cascading reservoir system for hydropower purposes on the Araguari River, located in the Triangulo Mineiro, Minas Gerais State, Brazil. It regulates three downstream reservoirs and provides irrigation, fish farming, and recreational uses. In addition to the reservoir for electricity production, the Nova Ponte Reservoir Watershed (BRNP) has excellent agricultural potential. Due to its relevance to the region, the present work aimed to assess how climate change scenarios could alter the BRNP monthly streamflow in the short (2019 to 2040) and medium-term (2041 to 2060) future. First, streamflow simulation was performed in the SWAT hydrological model, and it went through the multi-site streamflow sensitivity analysis, calibration, and validation processes in the SWAT-CUP software through the SUFI-2 algorithm. Then, streamflow simulations were performed with two future climate change scenarios proposed for the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) generated from the French model CNRM-ESM2-1 and the Japanese model MRI-ESM2-0, both part of the CMIP6 project. The scenarios evaluation in the BRNP hydrological response indicated a possible increase in the monthly affluent streamflow of the Nova Ponte Reservoir, as well as a more significant variation in the streamflow of the year's wettest months (from October to March) and a probable increase in the occurrence of extreme affluent streamflow. Although the results of increasing streamflow are initially favorable for the electricity and agricultural sectors, they may have implications for BRNP if they occur unexpectedly. Thus, for institutions and populations to prepare for future occurrences, the results of this work may be useful for developing adaptation strategies and reducing climate change impacts on the BRNP streamflow.