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No description available.

No Brasil, cerca de dois terços da capacidade total instalada de geração de energia elétrica e, em média nos últimos quinze anos, aproximadamente 90% da geração efetiva provêm das hidrelétricas. Este sistema inclui 170 usinas hidrelétricas de médio e grande porte existentes ou previstas até 2023, aproximadamente dois terços delas com capacidade de regularizar vazões e todas operando de maneira interligada. Restrições ambientais, técnicas, sociais e econômicas tem dificultado cada vez mais a implantação de empreendimentos hidráulicos contendo reservatórios de grande porte, tornando a maioria dos novos empreendimentos a fio d´água. Para compreender melhor o processo, este trabalho apresenta um levantamento da evolução anual da capacidade instalada e de armazenamento do sistema desde 1950 até a expansão prevista nos próximos 8 anos, em 2023. Os dados da década de 2000 e a previsão até 2023 de forma ainda mais acentuada indicam uma redução continua e significativa da capacidade relativa de regularização, com impacto direto nas decisões de operação e de expansão do sistema térmico complementar. A fim de avaliar as possíveis consequências da redução da capacidade de regularização, simulações foram realizadas no modelo HIDROTERM (ZAMBON et al. 2012); os resultados apontam para uma necessidade de ser complementar continuamente a energia hídrica, não só em períodos hidrologicamente desfavoráveis. / In Brazil, about two-thirds of electricity installed capacity and over the last fifteen years, on average 90% of energy consumed has come from hydropower generation. The hydro system includes 170 medium and large hydropower plants in integrated operation today or planned to be operational by the end of 2023, about two-thirds of them have large storage capacities to regulate flows. Environmental, technical, social and economic constraints have made it increasingly difficult to project and build new reservoirs with large storage capacities. As a result, newly built hydropower plants are mostly the run-of-river type. To better understand the process, this paper presents a historical survey of the installed capacity of hydropower and storage capacity of the system since 1950 and extends to the planned expansion over the next eight years, through 2023. Data from 2000 and projections through 2023 indicate a significant reduction of relative regulating capacity, which has a direct impact on decisions regarding operation and expansion of the complementary thermal system. In order to assess the possible consequences of the reduction in regulating capacity, simulations were performed on HIDROTERM model (ZAMBON et al. 2012); the simulation results point to a continuous need for complementing the hydropower generation, not only on hydrologically unfavorable years.

No Brasil, cerca de dois terços da capacidade total instalada de geração de energia elétrica e, em média nos últimos quinze anos, aproximadamente 90% da geração efetiva provêm das hidrelétricas. Este sistema inclui 170 usinas hidrelétricas de médio e grande porte existentes ou previstas até 2023, aproximadamente dois terços delas com capacidade de regularizar vazões e todas operando de maneira interligada. Restrições ambientais, técnicas, sociais e econômicas tem dificultado cada vez mais a implantação de empreendimentos hidráulicos contendo reservatórios de grande porte, tornando a maioria dos novos empreendimentos a fio d´água. Para compreender melhor o processo, este trabalho apresenta um levantamento da evolução anual da capacidade instalada e de armazenamento do sistema desde 1950 até a expansão prevista nos próximos 8 anos, em 2023. Os dados da década de 2000 e a previsão até 2023 de forma ainda mais acentuada indicam uma redução continua e significativa da capacidade relativa de regularização, com impacto direto nas decisões de operação e de expansão do sistema térmico complementar. A fim de avaliar as possíveis consequências da redução da capacidade de regularização, simulações foram realizadas no modelo HIDROTERM (ZAMBON et al. 2012); os resultados apontam para uma necessidade de ser complementar continuamente a energia hídrica, não só em períodos hidrologicamente desfavoráveis. / In Brazil, about two-thirds of electricity installed capacity and over the last fifteen years, on average 90% of energy consumed has come from hydropower generation. The hydro system includes 170 medium and large hydropower plants in integrated operation today or planned to be operational by the end of 2023, about two-thirds of them have large storage capacities to regulate flows. Environmental, technical, social and economic constraints have made it increasingly difficult to project and build new reservoirs with large storage capacities. As a result, newly built hydropower plants are mostly the run-of-river type. To better understand the process, this paper presents a historical survey of the installed capacity of hydropower and storage capacity of the system since 1950 and extends to the planned expansion over the next eight years, through 2023. Data from 2000 and projections through 2023 indicate a significant reduction of relative regulating capacity, which has a direct impact on decisions regarding operation and expansion of the complementary thermal system. In order to assess the possible consequences of the reduction in regulating capacity, simulations were performed on HIDROTERM model (ZAMBON et al. 2012); the simulation results point to a continuous need for complementing the hydropower generation, not only on hydrologically unfavorable years.

No description available.

O presente trabalho objetivou a formataÃÃo de uma metodologia de elaboraÃÃo de base de informaÃÃes para alocaÃÃo negociada de Ãgua visando subsidiar as decisÃes dos comitÃs de bacias e das comissÃes gestoras nas operaÃÃes dos reservatÃrios monitorados pela Companhia de GestÃo dos Recursos HÃdricos â COGERH. O AÃude Arneiroz II, localizado na bacia hidrogrÃfica do Alto Jaguaribe, no municÃpio de Arneiroz, estado do CearÃ, responsÃvel por perenizar 113 km do rio Jaguaribe, atà a sede da cidade de JucÃs, foi o reservatÃrio identificado para realizaÃÃo da supracitada pesquisa, por possuir uma complexa dinÃmica de perenizaÃÃo. A metodologia para elaboraÃÃo da base de informaÃÃes iniciou-se da validaÃÃo das informaÃÃes de oferta e demanda do sistema que compreende o AÃude Arneiroz II, dados do manancial e dos estudos de perda em transito ao longo do percurso perenizado. Assim, concluiu-se que, para este estudo de caso, o cenÃrio para o transporte de Ãgua que atende as demandas existentes de forma satisfatÃria e eficiente, se dà por meio de dutos abertos ou fechados, e nÃo pela perenizaÃÃo direta do rio Jaguaribe atà a cidade de JucÃs. O cenÃrio de perenizaÃÃo apresenta como prejuÃzo a diminuiÃÃo da garantia da oferta de Ãgua em pelo menos trÃs anos de seca extrema, enquanto que as perdas em trÃnsito representam 79% da vazÃo mÃdia liberada pela vÃlvula do AÃude Arneiroz II numa operaÃÃo anual de perenizaÃÃo. / This study aimed to formatting a methodology for development of information base for negotiated allocation of water in order to support the decisions of watershed committees and management committees in the operations of reservoirs monitored by the Company Management of Water Resources - COGERH. The weir Arneiroz II, located in the basin of Alto Jaguaribe in Arneiroz municipality, state of CearÃ, responsible for evergreening 113 km Jaguaribe river to the headquarters city JucÃs, the reservoir was identified for conducting the above research, by have a complex dynamic of evergreening. The methodology for compiling the information base began validation of information supply and demand system comprising Weir Arneiroz II, data source and loss studies in perennial traffic along the route. Thus, it was concluded that, for this case study, the scenario for the transport of water that meets existing demands satisfactorily and efficiently, is by means of open or closed ducts, and not by direct perpetuation Jaguaribe river to the city of JucÃs. The scenario presents evergreening as losses decreased guarantee the supply of water for at least three years of extreme drought, while the losses in transit represent 79 % of the average flow rate released by the weir Arneiroz II valve on an annual operation evergreening.

The Mekong River Basin (MRB) is one of the largest transboundary basins in the world shared between six south Asian countries. The Mekong river supports a population of more than sixty million people through irrigation and fisheries for their survival and hosts approximately 88,000 MW of unharnessed hydropower potential. The construction of the dams for the supply of energy has a wide-ranging effect on the downstream regions of reservoirs, causing unprecedented and devastating damage to the environment and livelihood of people. The dissertation examines the optimal operation of the dams for the equitable distribution of water between irrigation, domestic, and hydropower sectors with minimal effect on the downstream ecosystem by estimating the cascading effects of dams in the MRB. The hydrological characteristic of the MRB was simulated using the high resolution (1 km) Variable Infiltration Capacity (VIC) hydrological model with the Lohmann et al. (1996, 1998) routing scheme and general circulation models projection for the future till 2099. Remote sensing products were used for the derivation of the reservoir behaviors, while the net irrigation water requirement (NIWR) was simulated by the irrigation scheme embedded in the improved VIC model. The VIC-MODFLOW (VIC-MF) coupled model was used for the investigation of the interaction between the surface and groundwater movement. The hydropower potential of the dams was estimated using the modified Hanasaki et al. (2006) approach by explicitly considering the irrigation water demand from the expanding and intensifying agricultural activities. A system dynamic model for the MRB was developed for the sustainable optimization of water allocation to meet the needs from the irrigation, domestic, hydropower generation, and ecological sectors. Economic analysis was performed to evaluate the existing and future conditions over the resource surplus regions with consideration of social impacts. Streamflows in the MRB varied substantially with the peak monthly streamflow from 10 m3/sec to 40,000 m3/sec. The inflows to dams in both main river and tributaries are projected to increase from 1.2% to 25% under RCP 4.5 and a decrease of 28.5% - 74.7% under RCP 8.5 during 2020-2099 as compared to the historic mean. The NIWR for the MRB was calculated as 65,000 million m3 for the observed period (1981-2019) with a decrease of 0.25% for the future period. The groundwater interaction is expected to enhance the surface streamflow resulting in additional inflow to dams. The multipurpose reservoirs were able to generate the desired annual energy ranging from 15 GWh to 400 GWh along with satisfying more than 80% of the irrigation water demand. Similarly, the irrigation reservoirs also satisfied more than 80% of the water demand for irrigation and hydropower reservoirs to generate the required energy between 2 GWh and 18990 GWh. Climate change will enhance the hydropower potential with an average increase of 7.3% and 5.3% in the future under RCP 4.5 and RCP 8.5, respectively. The increase in the irrigated area (5% and 10%) reduces the energy generation of the multipurpose dams by 1.5%, however, the addition of a crop cycle lowers the energy generation by more than 10%. The system dynamics model showed the multipurpose dams produced annual energy of 316 GWh and satisfied more than 60% of the irrigation, municipal, and industrial sectors water demand during 2006-2019. Similarly, irrigation dams supplying more than 60% of the irrigation water demand, and 50% of the municipal and industrial sectors demand. Climate change has a positive influence on the performance of the dams. The assessment of the shadow price shows that the dam operation in Thailand, Laos PDR, and China will be sufficient to meet the water demands of the energy, irrigation, municipal, and industrial sectors, while the energy sector of Cambodia and Vietnam may experience adverse impacts. / Doctor of Philosophy / The Mekong River Basin (MRB) is one of the largest transboundary basins in the world shared between six south Asian countries. The Mekong river supports more than sixty million people through irrigation and fisheries for their survival and hosts unharnessed hydropower potential. The construction of the dams has a wide-ranging effect on the downstream regions of reservoirs, causing damage to the environment and livelihood of people. The dissertation studies the optimal operation of the dams in the MRB for the equitable distribution of water between irrigation, domestic, and hydropower sectors with minimal effect on the ecosystem. The streamflow of the MRB was simulated using the hydrological model with a routing scheme and future projection till 2099. Remote sensing products were used for the derivation of the reservoir behaviors. The water requirement for the irrigation and the groundwater-surface interaction was simulated by the irrigation scheme embedded in the hydrological model and groundwater coupled model. The hydropower potential of the dams was estimated by explicitly considering the irrigation water demand from the expanding and intensifying agricultural activities. A dynamic model for the MRB was developed for the sustainable optimization of water allocation to meet the needs from the irrigation, domestic, hydropower generation, and ecological sectors. Economic analysis was performed to evaluate the existing and future conditions over the resource surplus regions with consideration of social impacts. Streamflows in the MRB varied substantially between the dams based on the location at the mainstem or tributaries. The inflows to dams in both main river and tributaries in the future is expected to increase under low-carbon emission and decrease under high-carbon emission conditions. The irrigation water for the MRB was calculated as 65,000 million m3 for the period 1981-2019 and expected to decrease in the future. The groundwater interaction is expected to increase the surface streamflow resulting in additional inflow to dams. The multipurpose reservoirs were able to generate the desired annual energy ranging along with satisfying more than 80% of the irrigation water demand. Similarly, the irrigation reservoirs also satisfied more than 80% of the water demand for irrigation and hydropower reservoirs to generate the required energy. Climate change will favor the hydropower energy potential in the future. The increase in the irrigated area and the addition of a crop cycle reduces the energy generation of the multipurpose dams. The system dynamics model showed the multipurpose dams produced 97% of the demand energy and satisfied more than 60% of the irrigation, municipal, and industrial sectors water demand during 2006-2019. Similarly, irrigation dams supplying more than 60% of the irrigation water demand, and 50% of the municipal and industrial sectors demand. Climate change has a positive influence on the performance of the dams. The assessment of the shadow price shows that the dam operation in Thailand, Laos PDR, and China will be sufficient to meet the water demands of the energy, irrigation, municipal, and industrial sectors, while the energy sector of Cambodia and Vietnam may experience adverse impacts.

Efficient management of limited water resources in an irrigation reservoir system is necessary to increase crop productivity. To achieve this, a reservoir release policy should be integrated with an optimal crop water allocation. Variations in hydrologic variables such as reservoir inflow, soil moisture, reservoir storage, rainfall and evapotranspiration must be considered in the reservoir operating policy model. Uncertainties due to imprecision, subjectivity, vagueness and lack of adequate data can be handled using the fuzzy set theory. A fuzzy stochastic dynamic programming (FSDP) model with reservoir storage and soil moisture of the crops as fuzzy state variables and inflow as a stochastic variable, is developed to obtain a steady state reservoir operating policy. The model integrates the reservoir operating policy with the crop water allocation decisions by maintaining the storage continuity and the soil moisture balance. The reservoir release decisions are made in the model in 10-day periods and water is allocated to the crops on a daily basis. On comparison with the classical stochastic dynamic programming (SDP) model and a conceptual operation policy model, it is observed that the FSDP model, in general, results in lower release from the reservoir while maintaining lower soil moisture stress. However the steady state reservoir operation policy obtained using the FSDP model may not perform well in a short-term reservoir simulation. A fuzzy state short-term reservoir operation policy model with storage and soil moistures of the crops as fuzzy variables, is developed to obtain a real time release policy using forecasted inflow and forecasted rainfall. The distinguishing features of the model are accounting for (a) spatial variation of soil moisture and rainfall using gridded rainfall forecasts and (b) ponding depth requirement of the Paddy. On comparison with a conceptual operation policy model, the fuzzy state real time operation model is found most suitable for the application of the short term real time operation for irrigation. The real time operation model maintains high storage in the reservoir during most of the 10-day time periods of a year and results in a slightly lower annual releases as compared to the conceptual operation policy model. The effect of inflow forecast uncertainty is examined using different sets of forecasted inflows, and it is observed that the system performance is quite sensitive to inflow forecast uncertainties. The use of the satellite based gridded soil moisture in the real time operation model shows consideration of realistic situations. Further, three performance measures, viz., fuzzy reliability, fuzzy resiliency and fuzzy vulnerability are developed to evaluate the performance of the irrigation reservoir system under a specified operating policy. A fuzzy set with an appropriate membership function is defined to describe the working and failed states to account for the system being in partly working and partly failed state. The degree of failure of the irrigation reservoir system is defined based on the evapotranspiration deficit in a period. Inclusion of fuzziness in the performance measures enables realistic representation of uncertainties in the state of the system. A case study of Bhadra reservoir system in Karnataka, India is chosen for demonstrating the model applications.

As regras de operação apresentam-se como um dos principais elementos no planejamento e gerenciamento de sistemas de recursos hídricos. Em períodos de seca ou iminente seca, a aplicação de regras operacionais padrão pode apresentar-se insatisfatória, visto que períodos com déficits de grande magnitude podem ocorrer, levando o sistema a uma situação altamente vulnerável. Muitas vezes, isto pode ser evitado ou minimizado, utilizando regras de proteção, que admitem déficits menores na fase de cheia, ou de seca, ou em ambas fases de operação, aumentando assim o armazenamento no reservatório para precaver-se contra déficits de grande magnitude que possam ocorrer no futuro. Neste trabalho é desenvolvida uma rotina computacional para obtenção de regras operacionais de sistemas de reservatórios, considerando um novo tipo de regra de proteção. Aplicando os algoritmos genéticos – AGs, foram obtidas as estratégias operacionais do sistema produtor. Os resultados demonstraram que o emprego de técnicas de otimização como os AGs constitui uma ferramenta versátil para auxiliar na tomada de decisões. Além disso, as regras de proteção apresentaram-se muito úteis na prevenção contra déficits de grande magnitude / The operation rules constitute one of the main elements in the planning and management of water resources systems. The application of the standard operational rules can be present unsatisfactory in periods of drought or imminent drought. These rules can result in periods with deficits of great magnitude, leading the system to a highly vulnerable situation. Many times, this can be avoided or minimized using hedging operation rules that admit deficits in phases of flood, drought or in both phases of operation. Therefore, the storage in the reservoir is increased to prevent deficits of great magnitude that can occur in the future. In this work a computational routine to attain the operational rules of the reservoirs systems was developed, considering a new approach of hedging rule. The operational strategies of the Cantareira system were obtained through the usage of genetic algorithms (GAs). The results demonstrated that the use of optimization techniques, as the AGs, is an important tool to assist in the decision making. Moreover, the hedging rules were suitable in the prevention of deficits of great magnitude that can occur in the future

Este trabalho apresenta o desenvolvimento de um Sistema de Suporte a Decisão (SSD) para o planejamento operacional de sistemas hidrotérmicos de grande porte formados por um conjunto de usinas hidrelétricas e termelétricas, operados para geração e atendimento a demandas de energia elétrica. São consideradas também outras fontes de geração de energia, a expansão do sistema, transposições, usos múltiplos da água e restrições ambientais. O SSD integra um banco de dados com informações sobre o sistema hidrotérmico, uma interface gráfica para facilitar a edição dos dados e visualização dos resultados e os modelos de simulação e otimização. Os modelos do SSD chamado HIDROTERM baseiam-se na programação não linear (PNL). Nas diversas aplicações feitas do SSD com dados do Sistema Interligado Nacional (SIN), formado por 4 subsistemas e 128 usinas hidrelétricas ativas, foram obtidos resultados bastante satisfatórios demonstrando diversos avanços em relação ao modelo SISOPT de Barros et al. (2003), com destaque para a velocidade de processamento, o porte de sistemas aos quais o modelo pode ser aplicado e a representação bem mais completa do sistema hidrotérmico. Além do planejamento da operação do sistema hidrotérmico, o SSD pode ser aplicado também para diagnósticos do sistema existente, análises de impacto de mudanças em regras operacionais e de usos múltiplos da água, planejamento e avaliação de alternativas de expansão. / This paper presents the development of a Decision Support System (DSS) for the operational planning of large-scale hydrothermal systems formed by a series of hydroelectric and thermoelectric power plants, operated for the production and service demands for energy. Other sources of energy production, the expansion of the system, water transfers, multiple uses of water and environmental constraints are also considered. The DSS integrates a database with information of the hydrothermal system, a graphical interface to facilitate the editing of the data and display the results and the simulation and optimization models. The models of the called DSS HIDROTERM are based on the non-linear programming (NLP). In several applications made with the DSS with data for the Brazilian Hydrothermal System, formed by 4 subsystems and 128 active hydroelectric plants, very satisfactory results were obtained demonstrating various advances in relation to the model SISOPT from Barros et al. (2003), with emphasis on the processing speed, the size of systems to which the model can be applied and in a much more complete representation of the hydrothermal system. In addition to the planning of the operation of the hydrothermal system, the DSS can be applied also to the existing system diagnoses, analyses the impact of changes in operating rules and of multiple uses of water, planning and evaluation of expansion alternatives.