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Modelos de qualidade da água têm sido uma ferramenta bastante utilizada para a avaliação e previsão de resposta de interferências antropogênicas em recursos hídricos. Entretanto, em alagamentos artificiais, os prognósticos de emissões e remoções de gases de efeito estufa (GEE) para a atmosfera ainda incorporam grandes incertezas. O alto custo associado à necessidade de muitas medições e as estratégias para a calibração de modelos biogeoquímicos complexos representam um desafio. Neste contexto, a análise de sensibilidade dos parâmetros consiste em uma etapa importante para garantir o melhor usos de recursos computacionais e otimizar os esforços para a aquisição de dados de campo. Neste trabalho foi aplicado um modelo de qualidade da água 0D associado ao ciclo do carbono para a fase de pré-enchimento do aproveitamento hidrelétrico de SINOP, no estado do Mato Grosso, Brasil. Foi realizado um procedimento de análise de sensibilidade, em conjunto com o estabelecimento de critérios, para identificar parâmetros pouco significativos e auxiliar a seleção de parâmetros para calibração do modelo. Considerando a sazonalidade da região através de quatro campanhas realizadas na área de estudo, foram fixados 45% dos parâmetros por valores da literatura. Com o procedimento também foi possível verificar que alguns parâmetros se repetem entre os mais sensíveis para cada variável-estado. Assim, selecionando apenas 6 parâmetros para a calibração, foram escolhidos os 4 parâmetros mais sensíveis para a concentração de metano (CH4 ) na água, o mais sensível para a concentração do dióxido de carbono (CO2 ), e os 2 mais sensíveis para outras 4 variáveis estado do modelo.

RESUMO Os ecossistemas lacustres, especificamente aqueles considerados urbanos, têm sofrido alterações em suas características físicas, ecológicas e ambientais. Observam-se a intensificação da pressão antrópica e a ausência de planejamento na implantação de serviços públicos, especificamente no que se refere à distribuição de água e ao saneamento. Percebe-se que as lagoas urbanas têm sido alvo frequente de lançamento de efluentes e ligações clandestinas. Faz-se necessário construir um modelo de gestão que permita desenvolver propostas com vistas à mitigação dos impactos ambientais decorrentes das ações antrópicas. Nesse sentido, este artigo visa apresentar um panorama sobre as condições em que se encontram as lagoas no Rio de Janeiro, enfatizando os aspectos da gestão, tendo como pano de fundo as Lagoas Rodrigo de Freitas, Araruama e Jacarepaguá. Para o desenvolvimento da pesquisa, foram realizadas atividades de campo, entrevistas com moradores da região, com responsáveis pelo poder público e com militantes da sociedade civil. Foi possível verificar que as lagoas que se encontram no cenário privilegiado para o turismo e para a captação para abastecimento humano têm atenção especial, enquanto sistemas isolados encontram-se em processo de degradação de difícil recuperação. ABSTRACT Lake ecosystems, specifically those considered urban, have undergone changes in their physical, ecological and environmental characteristics. Intensification of anthropic pressure an absence of planning in the implementation of public services are observed, specifically with regard to water distribution and sanitation. Urban lagoons have been a frequent dumping location of sewage from illegal sewer connections. Therefore, it is necessary to build a management model that allows for the development of proposals aimed at mitigating the environmental impacts caused by anthropic actions. In light of this, this article strives to present an overview of the conditions of the lagoons in the state of Rio de Janeiro, highlighting managerial aspects and using the Rodrigo de Freitas, Araruama and Jacarepaguá lagoons as the basis for the analysis. To attain the proposed objectives, the research study conducted field studies and did interviews with people living in the region, public servants and environmental activists. The study found that lagoons that have touristic potential and can be used as source of water receive special attention, whereas isolated lagoon systems have been degraded to such a point that they are almost unrecoverable.

In Brazil, charging for water use is one of the five management tools provided for in the National Water Resources Policy, which aims to recognize the economic value of water, induce the rational and efficient use of water, and raise financial resources to finance actions contained in the watershed plan. After more than 20 years since its inception, the effective implementation of charging for water in Brazilian basins, despite its maturity, has yet a long way to go. Furthermore, where it is already implemented, there are many questions regarding the efficiency of the charges: has water been adequately priced as a natural resource endowed with economic value? To what extent has charging stimulated rationality and efficiency in water use? To what extent have the funds raised been effectively invested? How has the Brazilian charging model been in line with those in other countries? This paper presents a review of the state of the art of water charging in Brazil and proposes a reflection on the Brazilian charging model to contribute to a better application of this tool.

RESUMO A divulgação de informações sobre qualidade das águas para um público não especialista é fundamental para subsidiar ações políticas e institucionais de gestão dos ambientes aquáticos. Para tanto, índices de qualidade de água têm sido propostos por serem capazes de sintetizar em um único valor ou categoria a informação, normalmente descrita a partir de um conjunto extenso de variáveis de qualidade de água. Este trabalho propõe um novo índice de qualidade de água, IQAFAL, baseado em lógica nebulosa, direcionado para o ambiente lótico, desenvolvido com a colaboração do quadro de especialistas da área de qualidade de água do Instituto Estadual do Ambiente (INEA). O índice proposto foi aplicado a dados de qualidade de água do Rio Paraíba do Sul, obtidos pelo INEA, nos anos de 2002 a 2009. Os resultados do IQAFAL mostraram que esse índice foi capaz de descrever a qualidade da água desse trecho do Rio Paraíba do Sul, correspondendo satisfatoriamente às avaliações de qualidade de água contidas nos relatórios disponíveis. Verificou-se também que com essa metodologia foi possível evitar que a influência de uma variável em condições críticas fosse atenuada pela influência das outras variáveis em condições favoráveis, produzindo um resultado impreciso no índice final. ABSTRACT The dissemination of information on water quality for a non-specialist audience is essential to support political and institutional actions for the management of aquatic environments. Therefore, water quality indices have been proposed since they are able to synthesize into a single value or category information, usually described from an extensive set of water quality variables. This research proposes a new water quality index, based on fuzzy logic, aimed at lotic environments, developed through the collaboration of experts in water quality of the Rio de Janeiro Environmental Agency (Instituto Estadual do Ambiente - INEA). The proposed index was applied to water quality data from the Paraíba do Sul River, obtained by INEA, in the years 2002 to 2009. The results of IQAFAL showed that the index was able to synthesize the water quality of this stretch of the Paraíba do Sul, satisfactorily matching the assessments of the water quality assessments contained in the reports available. It was also noticed that with this methodology it was possible to avoid the attenuation of the influence of a variable in critical condition was attenuated by the influence of other variables in favorable conditions, producing an inaccurate result in the final index.

Water quality has been a global concern, as evidenced by UN Sustainable Development Goals. The current paper has focused on the Piabanha River rehabilitation as a case study which can be generalized to other similar watersheds. A monitoring program during a hydrological year was carried out, and different databases were used to calibrate and validate the QUAL-UFMG water quality model. Sanitation is the major problem in the watershed, notably in its headwater catchments, which concentrate the most urbanized regions where water quality is worse in the dry season due to low river flows. Thus, simulations of the river water quality have been performed through computational modeling suggesting organic load reductions in some sub-basins. In conclusion, some strategies to improve water quality have been discussed: (i) The water quality rehabilitation must consider progressive goals of pollution reduction starting with an initial implementation in a reduced area. The monitoring should be based on a few parameters relevant and simple to monitor. (ii) Pollution reduction ought to be carried out strategically with deadlines and intermediate goals that must be agreed upon between the stakeholders in the watershed. (iii) Watershed committees should supervise projects to improve water quality in partnership with the State Prosecutor&rsquo, s Office.

The current paper aims at analyzing the behavior of monthly precipitation in the Brazilian and Bolivian parts of the basin of the Madeira river, one of the most important sub-basins of the Amazon basin. Both parts account for 93 % of its total, and studies on this topic are lacking. The research was based on data from 41 rainfall stations considering a historic series from 1978 to 1998, which encompasses two of the largest El Nino events (1982–1983 and 1997–1998), hence its influence on the precipitation of the region was assessed as well. To study precipitation behavior, rainfall was regionalized using data clustering methods (Ward and K-means), with the basin being divided into five regions of homogeneous rainfall. Both methods were applied to the regions and showed similar results, providing a higher reliability for the clusters obtained. The results of the analysis show the homogeneous regions of the basin, the spatial variability of precipitation, seasonality and the influence of the phenomenon on the region.

The provision of raw water to urban supply systems is a global endeavor, and a great challenge to water resource managers of large metropolitan regions. A sustainable supply requires the integrated management of water quantity and quality, as well as the system’s adaption to land use and climate changes (e.g., deforestation, droughts). The available water security models inform about the current security status of a system based on the assessment of quantity, quality and adaption indicators. But they barely include risk variables in the analysis, which could help to improve the security assessment considering the historical records of indicators or their future projections. In the present study, a new method is developed that couples a security assessment based on the rating of pressure indicators acting on a watershed, such as water demand, ordinary and accidental contaminants, droughts, and environmental settings (e.g., share of forest cover), with a risk assessment based on pressure properties such as severity, occurrence and detectability. The method is framed in the “Failure Mode and Effects Analysis”, and was applied to the Rio das Velhas system that supplies a portion of Belo Horizonte metropolitan region (Minas Gerais, Brazil) with >4 million inhabitants. The results exposed unacceptable risks for water demand, ordinary contaminants and droughts, because of their high severity and frequency. The water demand risks were explained by data on current (2019) water scarcity and population growth projections (until 2036) that are likely to raise water consumption. The ordinary contaminant risks were deduced from information on current deviations of water quality parameters (e.g., dissolved oxygen, turbidity) from legal thresholds, and records (since 2007) of stream water contamination by untreated domestic effluents. Finally, the drought risks were explained by information on the persistence of stream flows below a legal reference flow, coupled with the identification of many (23) dry years in the available stream flow record (48 years). Overall, the proposed model was efficient in the evaluation of water security risk in the basin. The results obtained for the study area help to act on the required mitigation through prioritization of risk attenuation. Given the simplicity and modest data requirements, the method is helpful to decision makers and suited for replication in other similar regions around the globe.

This study analyzes hydrodynamic aspects of the Guabanara Bay estuarine system, which is in the southern coast of the state of Rio de Janeiro, Brazil. Hydrodynamic circulation patterns were characterized, with and without the influence of baroclinic pressure gradients due to water density differences. Typical summer and winter scenarios are considered. The evaluation adopted computational simulations of hydrodynamic circulation, using models from the environmental hydrodynamic base system, entitled SisBaHiA. The simulations indicate that by disregarding baroclinic effects in the pressure gradients, the mean water levels in the Guanabara Bay are underestimated up to 5 centimeters, depending on the region and season of year. However, the hydrodynamic circulation patterns with or without baroclinic pressure gradients are very similar, as shown by the circulation patterns maps in different tidal phases. RESUMO Este trabalho analisa aspectos hidrodinâmicos do sistema estuarino da Baía de Guanabara, localizado na costa sul do estado do Rio de Janeiro, Brasil. Padrões de circulação hidrodinâmica foram caracterizados, com e sem influência de gradientes de pressão baroclínicos devido a diferenças de densidade da água, para cenários típicos de verão e de inverno. A avaliação foi realizada por meio de simulações computacionais de circulação hidrodinâmica, com a utilização de modelos do Sistema Base de Hidrodinâmica ambiental, entitulado SisBaHiA. As modelagens indicam que a não inclusão de efeitos baroclínicos nos gradientes de pressão subestima níveis médifnefos de água na Baía de Guanabara em valores de até 5 centímetros dependendo da região e da época do ano. Entretanto, os padrões de circulação hidrodinâmica com ou sem gradientes de pressão baroclínicos são muito similares, como mostram os mapas de circulação em diferentes fases de maré.

Este artigo visou registrar o processo de implementação da cobrança pelo uso da água no território fluminense, iniciada em 2003 pela experiência pioneira de arrecadação pelo uso em rios federais da Bacia do Rio Paraíba do Sul. No ano seguinte, a cobrança foi ampliada para todas as águas estaduais (superficiais e subterrâneas), configurando-se em experiência singular no país por iniciá-la sistematicamente em todo o seu território. A despeito das polêmicas e tensões suscitadas inicialmente, o Estado avançou sobremaneira na estruturação do modelo de gestão baseado no tripé comitê-agência-cobrança. Os maiores desafios hoje se concentram em assegurar dois aspectos essenciais para a gestão dos recursos hídricos: (i) conferir agilidade/flexibilidade na aplicação dos recursos arrecadados e (ii) induzir maior racionalidade ao uso da água por parte dos serviços de abastecimento público em regiões caracterizadas por escassez crônica.

The land use characteristics of rural watersheds allow infiltration and consequent generation of groundwater flow, which constitutes a significant contribution to the hydrograph. Prior to this study, the MODCEL-COPPE/UFRJ model simulated only runoff, disregarding the losses occurred in rainfall-runoff process. Therefore, its application was more appropriate to urban watersheds, simulating flood events where surface flows prevail. This study aimed at representing the infiltration process and at incorporating the groundwater flow in the MODCEL’s structure, making feasible the rural watersheds simulation thus expanding its applicability as a hydrological model. A case study was performed in a 417 km2 subcatchment of Piabanha River, located at Petrópolis/RJ. It’s a predominantly rural watershed, with 80% of its area covered by forests. The model represented satisfactorily the seasonality and the magnitude of simulated recharges. In the parameter calibration procedure gave a coefficient of determination R2 = 0.75, comparing the calculated flows to the observed flows. During validation period, we obtained a coefficient of determination R2 = 0.76. The fit obtained was superior to that obtained in previous modeling of the same watershed by SMAP and MODCEL (previous version) and it was similar to TOPMODEL. In the hydrograph recession, new MODCEL presented R2 = 0.75, against 0.52 obtained in its previous version. RESUMO As condições de uso e ocupação do solo de bacias hidrográficas rurais favorecem a infiltração e a consequente geração de escoamento subterrâneo, que constitui significativa contribuição para o hidrograma. Previamente à elaboração deste trabalho, o modelo MODCEL-COPPE/UFRJ somente simulava a chuva efetiva, desconsiderando as perdas ocorridas no processo de transformação de precipitação em escoamento superficial. Desta maneira, sua aplicação era mais adequada a bacias urbanas, na simulação de eventos de cheia, com predominância de escoamentos superficiais. Este estudo objetivou individualizar a infiltração e incorporar o escoamento de base à estrutura do MODCEL, viabilizando a simulação de bacias rurais e ampliando a sua aplicabilidade enquanto modelo hidrológico. Foi realizado um estudo de caso em uma sub-bacia do rio Piabanha de 417 km2, localizada em Petrópolis/RJ. Trata-se de uma bacia predominantemente rural, com 80% de sua área coberta por florestas. O modelo representou satisfatoriamente a sazonalidade e a magnitude das vazões. Na fase de calibração dos parâmetros obteve-se um coeficiente de determinação R2 = 0,75, comparando-se as vazões calculadas às observadas. No período de validação, o R 2 obtido foi de 0,76. O ajuste foi superior ao que se obteve em modelagens pregressas da mesma bacia via SMAP e MODCEL (versão anterior), e similar ao TOPMODEL. Na recessão do hidrograma, o novo MODCEL apresentou R2 = 0,75, contra 0,52 obtido na sua versão anterior.

The use of the extraordinary hydroelectric potential of the Amazon Basin originated an increase in the offer of renewable energy in Brazil, which, in its turn, leads to conflicts and a lack of consensus among different players owing to the potential negative impacts related to the construction and operation of large hydroelectric power plants in relatively well preserved areas. In this context, environmental licensing is one of the national environmental policy’s main instruments for making decisions regarding the use of the hydroelectric potential, especially the rivers of the Amazon Basin. Nevertheless, this significant instrument has its limitations and requires adjustments in order to better aid the decision making process regarding the use of water resources and land with the goal of increasing the offer of electric energy.

This paper proposes a practical water resources-related index methodology (Hydric Index for Location of Industrial Facilities – HILIF) to provide preliminary guidance for location-based decision-making processes for new industrial sites, based on the likely effects on water resources in river watersheds, as applied to the conceptual phase of a project design. The framework of HILIF is established on the integration of three hydric factors: consumptive water availability, river carrying capacity, and flood vulnerability and effects of the drainage project. The proposed methodology for the application of HILIF is founded on Multi-Attribute Decision Making (MADM) using fuzzy logic (fuzzy MADM) to combine seven indicators into nine possible recommendation levels. Additionally, in order to illustrate the HILIF methodological approach, a case study of a project design using a cyclical analysis based on a hypothetical scenario was developed. In this context, three alternative sites (AA, BB, and CC) were considered for a nitrogen fertilizer plant in the Contas River Basin in the state of Bahia, Brazil. The results demonstrate that the HILIF methodology can support the conceptual project design by identifying the most adequate site alternatives for an industrial location within an integrated hydric perspective. In addition, the possibility of implementing modifications during the initial conceptual project was observed through cyclical analysis using multiple rounds for the same locational alternatives. For the present case study, the locational alternative preferred by project designers (Alternative CC) shifted from a classification of Not Indicated (NI) in the first round of HILIF application to a Fairly-Good Recommendation in the second round after modifications in the initial conceptual project. Thus, Alternative CC became nearly as adequate as Alternative BB, which was the best alternative site in terms of water, classified as a Good Recommendation in the first HILIF round. On a complementary basis, the results generated by the application of HILIF can also be utilized to support further complex studies for licensing proposes within the context of Environmental Impact Assessment (EIA) or Strategic Environmental Assessment (SEA).

Water quality monitoring is a complex issue that requires support tools in order to provide information for water resource management. Budget constraints as well as an inadequate water quality network design call for the development of evaluation tools to provide efficient water quality monitoring. For this purpose, a nonlinear principal component analysis (NLPCA) based on an autoassociative neural network was performed to assess the redundancy of the parameters and monitoring locations of the water quality network in the Piabanha River watershed. Oftentimes, a small number of variables contain the most relevant information, while the others add little or no interpretation to the variability of water quality. Principal component analysis (PCA) is widely used for this purpose. However, conventional PCA is not able to capture the nonlinearities of water quality data, while neural networks can represent those nonlinear relationships. The results presented in this work demonstrate that NLPCA performs better than PCA in the reconstruction of the water quality data of Piabanha watershed, explaining most of data variance. From the results of NLPCA, the most relevant water quality parameter is fecal coliforms (FCs) and the least relevant is chemical oxygen demand (COD). Regarding the monitoring locations, the most relevant is Poco Tarzan (PT) and the least is Parque Petropolis (PP).

Este trabalho analisa o saldo hidrico e propoe acoes para a garantia da quantidade das aguas na bacia hidrografica do rio Guandu, a principal fonte de agua para a regiao metropolitana do Rio de Janeiro. Um diagnostico da atual situacao aponta o problema de escassez hidrica, agravada com a crise hidrica atual na regiao sudeste, apos serem avaliados os usuarios cadastrados atualmente, com outorga ou nao, o sistema de transposicao Paraiba do Sul–Guandu e o avanco da cunha salina a partir da foz do rio principal da bacia. Nesse caso, o abastecimento de agua potavel para o consumo humano deve ser tomado como prioritario nas analises de futuras outorgas, em detrimento do aumento da cunha salina. Enfim, os cenarios foram previamente descritos para, entao, propor acoes na mitigacao de conflitos gerenciais da bacia e do abastecimento de agua para milhoes de pessoas no Rio de Janeiro.

RESUMO Tendo como referência indicadores operacionais relacionados a perdas de água e que constam na base de dados do Sistema Nacional de Informações sobre Saneamento (SNIS), baseados em resultados do ano de 2010, o presente estudo definiu critérios para o estabelecimento de parâmetros de avaliação de desempenho operacional - benchmarking , e como estudo de caso utilizou dados referentes a 22 prestadores regionais de serviços de saneamento no Brasil, notadamente as companhias estaduais de saneamento. Complementarmente, a partir do agrupamento dos prestadores de serviços em função do atendimento ou não ao benchmarking estabelecido, o trabalho compara o desempenho operacional de ambos os grupos, incluindo a avaliação à luz de diferentes estratos populacionais, bem como ressalta os resultados obtidos pelos prestadores que atenderam ao benchmarking , durante o período compreendido entre aos anos de 2002 e 2009. Da base SNIS foram utilizados os seguintes indicadores operacionais e de acordo com os critérios estabelecidos obtiveram-se os valores de benchmarking: índice e micromedição relativo ao volume disponibilizado (IN010) - 65,48%, índice de perdas no faturamento (IN013) - 24,10%, índice de perdas na distribuição (IN049) - 33% - e índice de perda por ligação (IN051) - 254,20 L.lig-1.dia-1. Dentre as 22 prestadoras analisadas, 4 atenderam ao benchmarking proposto. A avaliação de desempenho dos prestadores de serviço à luz dos estratos populacionais indica melhores resultados quando atendidos municípios de até 20.000 habitantes. Em geral, os prestadores que atendem ao benchmarking estabelecido para o ano 2010 apresentaram resultados operacionais similares durante o período de 2002 a 2009.

Guanabara Bay, a natural tropical embayment in Southeast Brazil adjacent to Rio de Janeiro, is important to the Brazilian economy as it provides areas for shipping, industry, recreation, and tourism. But commercial and residential urban development in the watershed results in water quality degradation. In Guanabara Bay, strong water quality gradients as a function of inputs and tidal flushing were evident. In the watershed, the urban and industrial areas degraded stream water quality, and the best water quality was in the upstream, rural areas. Steps have been initiated to collect or contain litter (ecoboats and ecobarriers) and reduce sewage discharge (sewage treatment plants). In spite of this, urban development continues to degrade Guanabara Bay ecosystem health. Large-scale international events hosted by Rio de Janeiro have brought widespread attention to Guanabara Bay pollution issues. Management actions have been identified to improve Guanabara Bay ecosystem health, including establishing a strong governance structure, restoring water quality in the rivers, bay and beaches, restoring habitats in Guanabara Bay and its watershed, and mitigating for climate change impacts. An ecosystem health report card was generated using monitoring data with stakeholder engagement for both Guanabara Bay and its watershed. The scientifically rigorous and transparent report card process can be used to track Guanabara Bay restoration progress.

In the realm of water resources management, new actors in Brazil are now involved in participatory decision making by means of water basin committees. This article proposes a decision-aid system, the JANUS structure, where the preference profiles of a water basin committee are blended with the technical evaluations performed by the basin's agency. This approach allows for the ranking of the actions to be implemented in the water basin. The proposed interactivity in the computational implementation of the JANUS structure is aimed at enhancing perception of each criterion to be adopted for assessment, while providing the consequences of preference choices.

This paper presents a procedure for decision analysis in water use conflicts among irrigators. It seeks feasible compromise term among decision makers by using optimal results for different proposals of solutions. The process is developed by applying the Graph Model for Conflict Resolution. The case study is the existing conflict among Coqueiros canal water users. This 45 km canal belongs to a complex irrigation and drainage canal network and it is located at Campos dos Goytacazes municipality, in the northern region of the State of Rio de Janeiro. Its basin has a potential irrigable area of approximately 14,000 ha. Six hypothetical scenarios have been built, each one corresponding to different alternatives to the conflict solution. In addition, two different tendencies were adopted by the Management Institution (MI) in order to take care of the conflict. The first tendency takes into account that the MI has no explicit preferences for any of its actions. As for the second one, the MI shows explicit preferences for the scenarios which provide more income taxes. Some scenarios that reached the state of equilibrium were analyzed to provide solutions to the conflict.

The first uranium production center in Brazil began operation in 1982. After 13 years of a non-continuous operation, the mining activities were suspended definitively. Uranium was extracted by open pit mining. Operations gave rise to approximately 12.4×10 6 m 3 of waste rock, while the mill process generated a volume of approximately 2.39×10 6 m 3 of tailings. Regardless the fact that some studies developed in this area exist, a well defined plan of action, aimed at the remediation and rehabilitation of the site, has not been implemented yet. The main sources of pollutants to the environment are the tailings dam, the waste rock piles and the open pit. Pyrite oxidation was found to be the driving force in the leaching of metal and radionuclides into environment. It was estimated that acid drainage generation will last for 600 and 200 years from the waste rock and tailings respectively. Accurate prediction of the release rate of metal and radionuclides from these sources and their transport in the subsurface is a critical factor to the assessment of environmental impact and to the development of effective remediation strategies. In prevailing practice, the source term is evaluated using the dissolution rate of waste form and the solubility of radionuclides. The fate of pollutants is addressed by the use of Kd-based ''reactive'' transport models. This standard practice has obvious shortcomings, mainly because it can not produce a realistic representation of the system under study. The alternative to overcome these shortages is using more sophisticate models that could represent real complex problems. Reactive transport codes are powerful tools in the evaluation of coupled thermal-hydrological-chemical processes and in the prediction of the long-term performance of remediation strategies. The difference between the predictions from these two approaches can be as high as several orders of magnitude. Generally, conventional approaches produce predicted values higher than the measured ones. On the other hand, the use of reactive transport model requires a good knowledge of the simulated hydrogeochemical system, along with the choice of appropriated algorithms that can represent the most important processes.

This study evaluated the performance of a sidestream membrane module combined with an aeration system for the treatment of municipal wastewater. To investigate the membrane's behavior and to control fouling, trials in laboratory units were conducted. In these tests, optimal values were established for some operational parameters, such as crossflow velocity, transmembrane pressure and air supply to continuously flush the membrane surface. Air supply improved the behavior of the permeate flux over time. After six hours operation, the stabilized flux was 35 L/m².h at a total pressure of 0.40 bar (wastewater pressure of 0.05 bar and air pressure of 0.35 bar) and Reynolds Number of 4,600. All permeate samples analyzed indicated absence of fecal coliform and Escherichia coli.Biorreatores com membrana para retenção de sólidos consistem em processos biológicos acoplados a módulos de membranas de microfiltração ou ultrafiltração. O presente estudo avaliou o desempenho de um módulo de membranas, combinado a um sistema de aeração, para o tratamento de esgoto doméstico. Com o objetivo de investigar o comportamento das membranas e minimizar os efeitos do "fouling", foram realizados testes em unidades em escala de laboratório, nos quais foram estabelecidos valores ótimos para alguns parâmetros operacionais, como velocidade tangencial no módulo, pressão transmembrana e vazão de ar inserida na linha de alimentação do módulo. Com a inserção de ar foi possível controlar melhor o comportamento do fluxo permeado ao longo do tempo. Após seis horas de operação, o fluxo se manteve em torno de 35 L/m².h para uma pressão total de 0,40 bar (pressão gerada pelo esgoto de 0,05bar e pelo ar de 0,35 bar) e Reynolds de 4.600. Todas as análises das amostras do permeado indicaram ausência de coliformes termotolerantes e Escherichia coli.

RESUMO Um estudo de campo foi realizado em um trecho de aproximadamente 70 km do rio Piabanha, localizado entre Petrópolis e Areal, na região serrana do Estado do Rio de Janeiro, para estimar as características de transporte e dispersão de contaminantes usando técnicas de traçadores fluorescentes. A análise dos resultados de dois trabalhos de campo, realizados no outono de 2012, permitiu determinar os valores de tempo de trânsito, vazão líquida, velocidade média e coeficiente de dispersão longitudinal. Utilizou-se os dados de vazão e velocidade média obtidos nos ensaios com traçadores para calibrar o modelo hidrodinâmico unidimensional Hydrologic Engineering Center’s River Analysis System (HEC-RAS). Considerando que parâmetros hidráulicos obtidos por métodos clássicos em rios com geometria muito irregular, como a do rio Piabanha, não são adequados para representar as características médias de um trecho, os ensaios com traçadores representaram uma boa alternativa para obtenção de parâmetros necessários a modelos hidrodinâmicos. Os resultados obtidos pelo modelo HEC-RAS apresentaram ótima concordância com os dados obtidos por meio dos ensaios com traçadores fluorescentes. ABSTRACT A field study was carried out on a reach of approximately 70 km of Piabanha river, located between Petrópolis and Areal, in the highlands of Rio de Janeiro State to estimate the transport and dispersion characteristics of contaminants using dye tracers techniques. The results of field campaigns, conducted in the fall of 2012, allowed to determine the values of transit time, flow rate, mean flow velocity and longitudinal dispersion coefficient. The flow rate and mean velocity obtained in situ with dye tracers were used to calibrate the one-dimensional hydrodynamic model Hydrologic Engineering Center’s River Analysis System (HEC-RAS). Whereas hydraulic parameters obtained by classical methods for rivers with very irregular geometry such as Piabanha river are not suitable for representing the average characteristics of a river stretch, the results obtained with tracers represented a good alternative to obtain parameters used in hydrodynamic models. The results obtained by the HEC-RAS are in excellent agreement with those obtained by the experiments with fluorescent tracers.

Rivers, as most bodies of water, are subject to eutrophication and water contamination, mainly from domestic sewage and industrial discharges from urban centers and agricultural areas. These growing human impacts result in a gradual loss of water quality and changes in biotic communities, including phytoplankton. Analyzing the dynamics of phytoplankton is important to understand how, in addition to hydrography and the physical, chemical and biological variables, human impact can be a controlling factor in this dynamic. In this study, we analyzed abiotic variables and zooplankton abundance to identify the factors controlling different phytoplankton attributes at six sampling points, in two climatic periods and three years, in the Piabanha River, a slowly flowing stream with to strong human impact beginning in its upper course, in a mountain region in southeastern Brazil. The results showed homogeneous environmental variables and different phytoplankton attributes along most of the stretch analyzed, except for sampling point 1, located in a preserved forest area but with nutrient concentrations limiting phytoplankton growth. The difference in flow between the two climatic periods (dry and wet) was not sufficient to change the total phytoplankton biovolume. Temperature seemed to strongly affect the phytoplankton response, with larger relative contributions from cyanobacteria in the wet period, with higher temperatures, and from phytoflagellates in the dry period, with lower temperatures. As expected, zooplankton showed no influence on phytoplankton dynamics, with a large contribution from small rotifers. In this tropical montane river, with slow flow and intense human impacts, nutrient concentrations and temperature were the main drivers of the spatial and temporal dynamics of phytoplankton, respectively. Made available in DSpace on 2022-07-13T12:20:02Z (GMT). No. of bitstreams: 1 6044.pdf: 1875134 bytes, checksum: 933bfa3718d81611ba9729d4a63e10be (MD5) Previous issue date: 2022

A modelagem hidrológica quando associada aos recursos do sensoriamento remoto e do geoprocessamento torna-se uma ferramenta importante, pois é capaz de estabelecer diferentes cenários da cobertura e do uso da terra e suas implicações na drenagem urbana, auxiliando no planejamento urbano. Entretanto, a relação entre o modelo chuva x vazão e tais técnicas, com finalidade de avaliar classificadores de imagens a partir de hidrogramas de cheia não foi encontrada na literatura, tornando esse o objetivo principal desta tese. Para isso, foram utilizadas três imagens de satélite de diferentes resoluções espaciais (0,5m, 5m e 15m) e três algoritmos classificadores (Máxima Verossimilhança, Máquinas Vetores Suporte e Análise Orientada a Objeto) e formados conjuntos denominado \"classificador-imagem\" para classificação da cobertura e do uso da terra. As áreas das classes dos usos da terra de cada conjunto \"classificador-imagem\" e os valores de Curve Number foram os principais dados de entrada do modelo chuva-vazão NRCS, que permitiu gerar os hidrogramas de cheia para cada caso. Os hidrogramas simulados foram comparados aos hidrogramas observados na bacia e avaliados, quanto a sua representatividade, pelo coeficiente de Nash Sutcliffe. As classificações do uso da terra foram avaliadas pelo Índice Kappa, com valores de 0,58 a 0,99 e pela Exatidão Global, com valores de 0,64 a 0,99. Para as vazões, o coeficiente de Nash Sutcliffe foi considerado satisfatório (NS0,75). Para fornecer subsídio a tomada de decisão, foi realizada uma análise multicritério dos conjuntos classificador-imagem, que permitiu classificar os conjuntos com maior desempenho: 1°) o classificador SVM e a imagem Landsat-8; 2°) o classificador MaxVer e a imagem WordView-II; 3°) o classificador NN e a imagem RapidEye. Hydrological modeling when associated with remote sensing and geoprocessing resources becomes an important tool, because it is able to establish different land use scenarios and its implications for urban drainage, assisting in urban planning. However, the relationship between the routing model and such techniques, for purpose to evaluate images classifiers from the runoff hydrograph was not found in the literature, making this the main objective of this thesis. Thereunto, three satellite images were used in different spatial resolutions (0.5m, 5m and 15m) and three algorithms classifiers (Maximum Likelihood, Support Vector Machine and Oriented Object Analysis) and composed sets called \"classifier-image\" for the land use classification. The areas of the land use classes of each set \"classifier-image\" and the Curve Number values were the main input of the routing model NRCS, which allowed generating the runoff hydrograph for each case. The simulated hydrographs were compared to the observed hydrograph in the basin and evaluated their representativeness through the Nash Sutcliffe coefficient. Kappa Index was calculated to evaluate land use classifications, with values between 0.58 to 0.99 and Global accuracy between 0.64 to 0.99. Towards the flows rates, the Nash Sutcliffe coefficient was considered satisfactory for two simulations (NS0,75). To provide subsidy to decision-making, it carried out a multi-criteria analysis of the classifier-image sets, that allowed to classify the set with higher performance: 1) SVM classifier and Landsat-8 image; 2) MaxVer classifier and WorldView-II image; 3) NN classifier and RapidEye image.

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

Desde 2004, o grupo de estudos do Laboratório de Hidráulica Computacional (LHC) estuda as taxas de recargas hidráulicas do Aquifero Guarani, na Bacia do Ribeirão da Onça. Entretanto, não havia se estudado a quantificação do escoamento superficial. Para sanar esta deficiência, este trabalho visou analisar as metodologias de estimativa de vazão com qualidade para a Bacia do Ribeirão da Onça. Para a realização do trabalho, foi adquirido o equipamento Flo-Tote3, capaz de medir velocidade e nível d\'água. A princípio, o equipamento foi verificado e comparado em laboratório, medindo velocidades 3% inferiores que o molinete e estimando vazões de 0,5 a 7,2% de diferença que o vertedor triangular. No Ribeirão da Onça, foi escolhida e construída uma seção de controle de vazão e instalado o Flo-Tote. O equipamento mediu velocidades 5% inferiores que o molinete, com variações de 0,3 a 8,7%. Além disso, um vertedor circular foi instalado em 6 ocasiões, resultando em vazões de 3 a 15% inferiores as vazões estimadas pelo molinete, em virtude do vazamento que ocorreu entre o vertedor e a parede de concreto. A partir de dezembro de 2007, foram iniciadas medições de níveis d\'água com a construção do linígrafo e estimadas as vazões de modo contínuo com o auxílio de equações teóricas. Como a jusante da seção de controle de vazão existe um sistema de bombeamento, as equações para determinar a vazão sofrem interferencias. Entretanto, foi aplicado o método das isotáquias, que utiliza valores de velocidades e níveis d\'água para o cálculo da vazão e que não sofre interferências com o represamento e instalações de vertedores. Apesar de ocorrer problemas de falta de energia e de manutenção, o escoamento superficial foi quantificado com qualidade para futuros estudos da área afim. Since 2004, the group of studies of the Computational Hydraulic Laboratory (LHC) studied the rates of water recharge in the Guarani Aquifer recharges water in the Ribeirão da Onça basin. However, it had not studied the quantification of runoff. To remedy this deficiency, this study aimed to analyze the methodologies for estimation of flow quality for the Ribeirão da Onça basin. To carry out the work, it was acquired a Flo-Tote3, capable of measuring velocities and water levels. First, this equipment was checked and compared in the laboratory, measuring velocities 3% below, those obtained using flowmeters and 0.5 to 7.2% differences when compared with results using triangular weir. In Ribeirão da Onça, was chosen and built a section of control flow and installed the Flo-Tote. The equipment measured velocities 5% below the current meters, with variations from 0.3 to 8.7%. In addition, a circular weir was installed on 6 occasions, resulting in flow rates from 3 to 15% lower than those estimated by current meters because of the flow that occurred between the bridge and weir. Since December 2007, started the measurements of water levels and the estimated flow on a continuous basis with the aid of theoretical equations. As the downstream section of the control flow is a pumping system, the equations to determine the flow are interfered. However, it was applied the method of the lines of the same velocities, which uses values of velocities and water levels to calculate the flow without interference with the impoundment and installation of weirs. Despite the problems of lack of energy and maintenance, the runoff was quantified with quality for future studies of the area.

Os aspectos quantitativos regem as práticas de engenharia visando o gerenciamento de reservatórios. Entretanto, a preocupação em relação aos aspectos qualitativos da água tem aumentado, já que um número cada vez maior de reservatórios estão sendo utilizados para vários tipos de usos. No processo de gerenciamento de reservatórios é necessário que se leve em consideração todos os usos que serão beneficiados pelo sistema em questão. Nesse sentido, o objetivo do trabalho foi o emprego de técnicas computacionais para análise quanti-qualitativa dos usos múltiplos do reservatório de Barra Bonita - SP, realizando simulações computacionais através do modelo MIKE BASIN; propondo e testando um modelo de otimização com programação não-linear baseado no método das restrições e incorporando o uso de geotecnologias para análise espacial (distribuição horizontal) e temporal (sazonalidade) da qualidade da água do reservatório. Selecionou-se o reservatório de Barra Bonita para análise, devido aos usos múltiplos da água (geração de energia, navegação, recreação, turismo e pesca) e a presença de uma eclusa para transposição do desnível entre a jusante da barragem e o reservatório de acumulação da hidrelétrica, o que torna o reservatório uma área de estudo diferenciada. Os resultados das simulações realizadas no modelo MIKE BASIN para avaliar os usos múltiplos do reservatório, demonstraram que o melhor cenário foi o que estabeleceu prioridades iguais para a geração de energia e a navegação. A maximização da geração de energia hidroelétrica, através do modelo de otimização, não prejudicou os outros usos do reservatório (principalmente a navegação) e, mesmo no período seco, a energia média gerada pelo modelo registrou valores acima da energia média real gerada pela Usina Hidrelétrica de Barra Bonita-SP (período de 2001 a 2005). O emprego de geotecnologias (software Surfer) proporcionou boas condições para análise espaço-temporal da qualidade da água, quando aliado ao conhecimento sobre as características e condições do ambiente de estudo. Os dados obtidos em campo, demonstraram que algumas variáveis analisadas, como a condutividade elétrica e a turbidez aumentam significativamente do período seco para o chuvoso, pois estão diretamente relacionados com o aporte de material orgânico e inorgânico. O potencial hidrogeniônico (pH) sofre uma variação muito pequena do período seco para o chuvoso, mas seus valores variam espacialmente, sendo encontrados valores maiores no compartimento da barragem para o período seco, e no final do braço do rio Piracicaba para o período chuvoso. Quanto ao oxigênio dissolvido, este aumenta bastante do período chuvoso para o seco, mas em ambos os períodos as maiores concentrações são encontradas no final do braço do rio Piracicaba - SP. Ressalta-se, que apenas o oxigênio dissolvido (estação seca) não se enquadrou no padrão da Resolução CONAMA nº 357/2005, para águas de classe II. The quantitative aspects rule the engineering practices aimed at reservoirs management. However, the concern about the qualitative aspects of water has increased, since a growing number of reservoirs are being used for many kinds of applications. In the process of reservoir management it is necessary to take into consideration all the uses that will benefit from the system itself. Hence, the objective of this study was the use of computational techniques for quantitative and qualitative analysis of the multiple applications of the reservoir of Barra Bonita - SP, performing computer simulations using the model MIKE BASIN, proposing and testing an optimization model with non-linear programming based on the constraint method and incorporating the use of geotechnologies for spatial (horizontal distribution) and time (seasonal distribution) analysis of the reservoir water quality. It was selected the reservoir of Barra Bonita for analysis because of the multiple applications of the water (power generation, navigation, recreation, tourism and fishing) and the presence of a lock for transposition of the gap between the dam downstream and the power plant accumulation reservoir, which makes the reservoir a different area of study. The results of the simulations performed in MIKE BASIN model to evaluate the multiple applications of the reservoir showed that the best scenario was the one in which the priorities were the same for power generation and navigation. The maximization of the hydropower generation through the optimization model, did not impair other uses of the reservoir (mainly navigation) and even in the dry season, the average power generated by the model registered values above the average real power generated by the Hydroelectric Power Plant of Barra Bonita-SP (from 2001 to 2005). The use of geotechnologies (Surfer software) provided good conditions for space-time analysis of water quality when coupled with the knowledge about the characteristics and conditions of the studied environment. The data obtained showed that some variables, such as electrical conductivity and turbidity significantly increase from the dry season to the rainy season, since they are directly related to the supply of organic and inorganic materials. The hydrogen potential (pH) undergoes a very small variation from the dry season to the rainy season, but its values vary spatially, with higher values found in the compartment of the dam during the dry season, and at the end of the arm of the Piracicaba river during the wet season. The dissolved oxygen greatly increases from the rainy season to the dry one, but in both periods the highest concentrations are found at the end of the arm of the river Piracicaba - SP. It is emphasized that only the dissolved oxygen (dry season) did not fit the pattern of CONAMA Resolution nº 357/2005, to class II waters.