Sistema Hidráulico Paraíba do Sul - Guandu: uma avaliação do risco futuro de seca sob mu-danças climáticas

Abstract

Climate change poses a threat to the sustainable development of the planet, leading to a greater occurrence of severe weather events. These events are already causing significant impacts on social and economic development, especially due to water scarcity. In Brazil, drought events impact thousands of people annually. In Southeast Brazil, the droughts related to the water crisis that occurred between 2014 and 2016 involved one of the largest population agglomerations in the country, in addition to the Paraíba do Sul-Guandu Hydraulic System. Both in its area of coverage and in the Metropolitan Region of Rio de Janeiro, the Paraíba do Sul river basin is essential for the provision of water for multiple uses, including human supply, energy generation, industrial use and agriculture, which sometimes conflict in scenarios of scarcity. Thus, it is essential to carry out studies that support debates on the compatibility of internal and external interests in the Paraíba do Sul basin, especially those that occur in the midst of extreme weather events. The possibility of quantifying climate risks allows adaptative decisions to be taken and the impacts of such events to be minimized, reducing the degree of vulnerability of a given region. With that been said, this work aimed to carry out an assessment of the future risk of drought for the Paraíba do Sul-Guandu Hydraulic System considering models and climate change scenarios endorsed by the CMIP6. The global models presented sufficiently high correlations with the climatology observed in the historical period, demonstrating that they are capable of capturing seasonal and interannual variations in the region despite the uncertainties intrinsic to climate variability. According to the results of this research, it was possible to observe that future projections tend to identify less frequent and less intense droughts when compared to the observed data, generally pointing to a more favorable future in terms of surface runoff and water availability; which does not rule out the occurrence of exceptional drought events or even other extreme events, such as floods and inundations.