Estudo comparativo, aplicação e definição de metodologias apropriadas para a determinação da vazão ecológica na bacia do rio Pará, em Minas Gerais

Abstract

In the recent years, despite the undeniable progresses at the institutional and legal instances, it has been observed a growing demand for water resources, whose restrictions, under both aspects of quality and quantity, are well known. This tendency has the undesirable effect of aggravating the conflicts among different uses and users of water resources, thus making even more necessary the development and improvement of management techniques that promote sustainability, under current and prospective scenarios. The notion of ecologic flows is related to the idea of preserving the existing aquatic biota in water bodies, thus allowing the water environment to sustain the integrity of the natural processes interfacing the physical and biological phenomena, especially in their relations linked to variations of hydrological regime. This research presents a comparative study among recent methods for determining ecological flows, focusing on those based on habitat classification, such as the WAIORA and RHYABSIM models, searching for the one or the ones that are adequate for the Brazilian reality, taking into account (i) the physical and chemical needs of the fish populations, (ii) the modern concepts of water resources management and (iii) economic restrictions. The study was carried out in one reach of the Pará river, downstream the Cajurú hydropower plant, located in the south-central region of the Brazilian state of Minas Gerais.