Metodologias hidrológicas para dimensionamento de vazão residual de barragens, em rios intermitentes, em pequenas bacias hidrográficas no semiárido mineiro

Abstract

Public management of water resources seeks to establish an adequate balance between water use and the preservation of its ecosystem functions. In the context of the semi-arid region of Minas Gerais, a region characterized by water scarcity, it is imperative to adopt management methodologies that consider hydrological particularities, such as the intermittency of surface water sources. In Minas Gerais, the use of the reference flow rate Q7.10 is established as a parameter for the entire state territory. However, this approach has proven, in some situations, inadequate for intermittent water sources, which have different characteristics. In this sense, an evaluation of three different methodologies for dimensioning water availability in scenarios of dams in intermittent watercourses was carried out, based on the methodologies of Tennant or Montana, Q90 and Q95. The results, obtained from the application of these methodologies in two case studies, showed that the Q95 permanence curve is the most appropriate to represent the hydrological behavior of water structures in the semi-arid region of Minas Gerais, reflecting more accurately the specificities of this region.