Transposição das águas do rio São Francisco para a bacia do rio Paraíba: uma avaliação da sinergia e sustentabilidade hídrica utilizando o modelo de rede de fluxo AcquaNet.

Abstract

In the Brazilian northeast semi-arid region, the water resources scarcity has been one of the main development constraint factors, despite of the vast number of water accumulation infrastructures; being one of the worldwide regions with the highest storage reservoir indexes. The region presents a semi-arid climate, with adverse water balance, compounded by an inadequate management of river basins and a low efficiency water use. To address the population growth and development and the allocation priority of water for human supply, as advocated by Law 9.433/97, the need for adequate management of water resources in the region should be imposed, bringing the existing water stocks to meet, with security, the current demands. Water sustainability in northeast semi-arid region passes through the adoption of a water resources policy for the region, which considers the increasing levels of protection against drought effects, regarding the environmental, social and economic vulnerabilities. As the concept of sustainable development requires a systemic analysis and actions regarding the integrated water resources management, projects for inter basin water transposition can be considered, as the case of the water transposition of San Francisco river to the Northeast of Brazil, which should provide an additional water supply to the receiving basins, reducing the uncertainties in meeting future water demands. In this context, part of this dissertation seeks to give an overview of the San Francisco river water transposition project, currently known as Project of the San Francisco River Integration with the Brazilian Northeast river basins, regarding the East Axis project, in which is inserted the system under study that is located in the Paraiba river basin, at the Paraiba State. AcquaNet simulations, which is based on network flows mathematical model, were performed for different scenarios of operation policies for a system of four reservoirs, which are located in sub basins of the upper and middle part of Paraiba River, in order to quantify the Hydro Synergy of the system. The demands of human supply and irrigation, as well as the indicators of sustainability such as Reliability, Resilience and Vulnerability, were calculated. The results have shown that care must be taken when establishing operating rules and means of water transport, as well as the amount of water to be transposed from San Francisco river, regarding the increase of water availability and use efficiency. It is also hoped that the produced results and analysis help to increase the understanding on the subject in academic and technical means.