Reservatórios de acumulação de água: novas propostas para o dimensionamento e representação dos seus efeitos

• Ano de defesa: 2013
• Autor(a) principal: Nunes, Aline de Araújo
• Orientador(a): Pruski, Fernando Falco
• Banca de defesa: Cecílio, Roberto Avelino , Martinez, Mauro Aparecido , Pereira, Silvio Bueno
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Engenharia Agrícola
• Departamento: Construções rurais e ambiência; Energia na agricultura; Mecanização agrícola; Processamento de produ
• País: BR
• Palavras-chave em Português: Armazenamento de água; Vazão; Recursos hídricos
• Palavras-chave em Inglês: Water storage; Flow; Water resources
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA
• Link de acesso: http://locus.ufv.br/handle/123456789/3634

One of the main problems faced nowadays is the difficulty in supplying the water demand required by society, being used for this purpose the process of water storage in reservoirs. The construction of regularization reservoirs modifies the streamflows distribution in rivers, occurring an increase of the value of available low flow, which tends to approach of average streamflow value. The increase of water availability, in turn, enables that water use grants are granted for a larger number of users. Considering the randomness of the streamflow occurrence, in other words, the impossibility of occurrences predicting in long-term, it is not possible to predict accurately the size of water reserve that is needed to supply the demands of drought periods in the future. The water managers have increasingly sought improvements in the techniques of sizing reservoirs. In the perspective of simplicity, without escaping at a technical-scientific basis, the accumulated difference method is an expressively diffused method, but with limitations regarding the dependence on the characteristics of the available database. The work was divided in two papers, and in Paper I the objective was to evaluate the impact of use of regularization reservoirs on water availability along the hydrography, and, for that, was made a case study for Entre Ribeiros river basin. The impact of reservoir construction on water availability was evaluated based on the effect that water storage potentiates in relation to the replacement of superposed flows by flows distributed in time and in the possibility of considering the criteria for conceding water use grants in conditions of water storage replacing to the criteria used in natural conditions. Considering the replacement of superposed flows by flows distributed in time the increase in potentiality of water resources use was up to 60% and at the consideration of the criteria for conceding water use grants in conditions of water storage replacing to the criteria used in natural conditions there was an increase in water availability up to 1,610%. In Paper II the objective was to propose modifications in accumulated differences method to overcome the limitations related to the dependence of the database start year and the impossibility to combine the reservoir capacity to a return period. In order to achieve the independence from database start year was proposed the creation of synthetic series and aiming to associate the reservoir capacity to a frequency factor (return period) was applied the Gumbel distribution to the capacity values estimated from these series. Considering β values (proportion of the average streamflow to be regularized) greater than or equal to 0.75 the creation of synthetic series was of great efficiency to overcome the limitations related to the dependence of database start year, as well as the association of the reservoir capacity to return periods greater than or equal the number of years of database was of great applicability.