The relationship between Man and Nature can be divided into three ‘eras.’ The first era refers to a time when Man was dominated by Nature, governed by her fluctuating seasons and at the mercy of her erratic moods. Man’s advancement brought into being the Machine, which enabled Man to move into a second era. This era brought about a brief state of equilibrium between Nature and Man, before Man advanced even further and faster into a third era in which Man and Machine dominated Nature. Man’s appropriation of Nature’s resources is his most intimate experience of the Natural world. However, in this third phase of development, Man has negated the ‘natural’ source of Nature’s resources and has thus disconnected himself from her. As a result of this disconnection, the third era is characterised by an imbalance which is leading towards the possibility of Man tipping off the scales entirely. This thesis explores the possibility of a fourth era in which Man and Nature once again achieve an equilibrium of mutually beneficial symbiosis. A fourth era would be the setting of a mend in the severed Man-Nature relationship. A ‘reconnection’ could be achieved through a renewed understanding of the systems, both natural and technological, that supply Man with Nature’s resources. The ‘Machine’ that is the Vaal Dam Wall and its surrounds was chosen as a locus for the theoretical application of a form of inhabited resource infrastructure that takes steps towards a fused Man-Nature entity. The dam wall is a significant piece of existing infrastructure that plays a major role in the capture, storage, and distribution of water to people in Gauteng, South Africa’s economic powerhouse. A legible, multi-use intervention sensitively placed on this site could reconnect the water-users to the natural water resource that is so vital to their livelihoods. The intervention is in the form of a visitor centre which incorporates water purification and hydroelectric power generation as well as a management facility for the Department of Water Affairs, the entity with jurisdiction over the Vaal water system and dam wall site. The Vaal Dam Visitor Centre could provide much-needed infrastructure to the chosen site in its un-realised capacity as a locus for tourism, education, research and management. In doing so, the Centre could be the ‘Machine’ that reconnects Man to Nature through responsible use and understanding of her resources.

Student Number : 9210081T - MSc dissertation - School of Geosciences - Faculty of Science / The occurrence of large, massive iron oxide deposits throughout the Bushveld Complex, South Africa, and its associated roof-rocks is well known. The style of mineralisation and the associated alteration exhibits many characteristics of iron oxide-copper-gold (IOCG) type deposits. The contained mineralisation is dominated by iron oxide and fluorite and is accompanied by a diverse polymetallic association, with anomalous fluorite, copper, gold, barite, uranium and LREE. The Ruigtepoort orebody, located in the western Bushveld Complex, is such an example and is surrounded by some 20 smaller occurrences in the upper stratigraphic portions of the Bushveld Complex, all displaying strong structural control. These IOCG bodies occur as narrow veins, hydrothermal breccias, subhorizontal sheets, or as pipe-like intrusions usually utilising pre-existing structures. Set in red Nebo granite, the mineralised core consists of severely chloritised rock that is haloed by progressively less-altered granite. The alteration passes from the chlorite core to more hematite-phyllosilicate-dominated alteration, to sericite-illite-dominated alteration; followed by the relatively fresh country granite. These alteration haloes dissipate rapidly away from the body over only a few metres. Sodic-calcic alteration described in other IOCG is not locally observed. Extensive zones of barren feldspar-destructive alteration exist, including K-metasomatism, sericitisation and silicification. Multiple alteration episodes appear to have occurred, resulting in extensive overprinting and a very complex paragenesis. The primary mineral assemblage consists of Fe-chlorite, fluorite, quartz, hematite, and specularite, with accessory pyrite and chalcopyrite. Multiple generations of hematite, quartz, fluorite and chlorite are also observed. At other localities, the assemblage is dominated by magnetite-actinolite-britholite. Significantly enriched concentrations of Au (2 g/t), Cu (0,45 wt%), Ba, Y and LREE are encountered in the small, mineralised core. A fluid mixing model is proposed characterised by an initial highly-saline, sulphur-poor magmatic fluid which mixed with a lower temperature oxidised, surficial fluid. Structure was probably a significant factor in determining the initial distribution of hydrothermal centres and the overall morphology of the entire system. Subsequently, continuous brecciation, alteration, mineral precipitation and fault activity helped develop the hydrothermal centres into a complex array of variably mineralised, lenticular, pipe-like and irregularly shaped breccia bodies.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2016. / Gold mining of the Witwatersrand Basin reefs has been responsible for the rise of Johannesburg as an economic centre of South Africa. While mining provided a base for business and infrastructure development for the region, it has also generated social and environmental problems for the country. Tailings storage facilities (TSFs), a common sighting around Johannesburg and across the entire basin, have been built to contain the processed waste following extraction of gold from the pyrite containing quartzite ore. When the fine grained waste is exposed to atmospheric conditions, oxidation of remnant sulphides occurs resulting in acidic, metal rich and sulphate rich plumes that enter the environment through surface and groundwater systems. This thesis sought to better understand the release, transport, dispersal and fate of metals emanating from TSFs and their remnant footprints on the Witwatersrand. These metals included aluminium, copper, chromium, iron, manganese, nickel and uranium and are known to be toxic to humans depending on their concentration and speciation. Traditionally, analytical methods have been employed in studies focussing on the characterisation of some of these processes in the region. While these studies have generally conducted quantitative assessment of the extent of pollution, little comprehensive interrogation and fingerprinting of the processes that are influential in determining the potential risk posed by metals has been done. This has largely been due to the shortcomings of analytical methods to determine these. To this end, this research has employed geochemical modelling to complement the traditional analytical methods. The approach to study the release of metals from TSFs involved assessment of the partitioning of metals within tailings and their potential release using batch and sequential extraction methods. Processes of metal release within the tailings were simulated through geochemical modelling (using the PHREEQC and Geochemist’s Workbench codes). The simulations were based on the percolation of rainwater through these layers and the changes in its chemistry along the path. The potential seepage of this plume along the path was then correlated to observed efflorescent mineral crusts that are temporary sinks for metals and are a common feature in the vicinity of the tailings and water bodies such as ponds and streams. The potential impact of the mineral crusts on the water chemistry of receiving water systems following their dissolution was assessed using forward geochemical modelling. The transport of the metals in groundwater was also studied. This involved simulations of the transition in chemistry of a plume from a TSF along an aquifer of known composition. This was based on a 1-D reactive transport model constructed using information from sequential extraction work on the aquifer rock (to identify the key minerals to consider) and site data (mainly flow rates) from previous studies. The processes occurring in the removal of metals from acid mine drainage (AMD) through a permanent sink in the form of a pump-and-treat plant in the Central Goldfield of the basin were simulated using PHREEQC. The findings from the research showed that two different plumes were produced from an abandoned TSF as a result of rainwater percolation, notably a plume produced from the dissolution of secondary salts formed in the oxidised layer and a sulphuric acid rich plume in the unoxidised layer. These differences were apparent in the geochemical composition of the mineral crusts collected on the walls of tailings dumps and from a pond into which the plumes were draining. On dissolution, mineral crusts were found to produce acidic solutions with crusts containing predominantly Fe producing pH values below 3. The simulated dissolution of various types of mineral crusts gave insight into the impact of minerals present in the smallest amount. This showed that the bulk mineralogy as determined by analytical techniques such as PXRD and remote sensing could not be used with confidence to deduce the impact of the mineral crusts on receiving water bodies. The characteristics of surface plumes released from tailings TSF were compared to other water systems in the area around Soweto, with complementary interpretation conducted using chemometric methods. From principal component analysis (PCA), surface water systems were found to form distinct groups largely influenced by mineral solubility, alkalinity and dissolved oxygen content. The 1-D reactive transport simulations involved acidic, metal and sulphate rich water ingressing the aquifer (below the TSF). Several scenarios were modelled including simulations with different dolomite contents; allowing for surface complexation and the presence of cation exchange surfaces. At a point 500 m from the water ingress in the dolomite rich aquifer, Fe and Mn were largely precipitated out (as confirmed by sequential extraction results on the aquifer rock) while the sulphate concentration was reduced by almost half. On the other hand, Ca concentrations were conservative largely because of continuous dissolution of dolomite and precipitation of gypsum along the flow path. The simulations of the high density sludge treatment plant involved forward modelling of the treatment process with the sludge responsible for the removal of trace metals from the incoming acid mine drainage. The model can be of use for cost and process optimisation at the facility. This research has had notable outputs in the form of publications; models on metal release, transport and attenuation; and models on pump-and-treat processes. These will form an important repository of information and for benchmarking any further studies related to AMD. / MT2016

O transporte de sedimentos fluvial constitui-se de um fenômeno complexo, no qual inúmeras variáveis estão envolvidas. A construção de barramentos aumentou o interesse no entendimento dos efeitos hidráulicos desse tipo de obra sobre o rio. A retenção de sedimentos no reservatório formado pela construção da obra e a erosão a jusante da contenção das águas podem produzir efeitos desastrosos ao sistema fluvial. A utilização de modelos matemáticos para representar a natureza e estudar o fenômeno do transporte de sedimentos vem sendo aprimorada. O objetivo deste trabalho foi avaliar as conseqüências da construção de barramentos nos rios, através da aplicação de formulações hidráulicas de movimento de água e de sedimentos na forma de algoritmos computacionais. Para o estudo do transporte de sedimentos em canais naturais foi utilizado o modelo desenvolvido por CHEN (1973) enquanto para a análise da capacidade de carga de sedimentos em função da vazão e características da seção aplicou-se o de TOFFALETI (1969). Realizou-se estudo de caso, com a aplicação dos modelos matemáticos à Barragem do Castanhão, no Estado do Ceará. A utilização dos regimes hidrológicos dos eventos de cheia para o reservatório, com tempo de retorno de 10, 20, 25, 50, 100 e 1000 anos, indicaram uma erosão acentuada de até 1,00 m de profundidade logo após o barramento. A estabilização do fenômeno de transporte foi estimado a uma distância de 10,0 Km a jusante da obra. Entretanto, vazões afluentes médias e vazões inferiores a 100 m3/s parecem não ter efeito sobre a morfologia fluvial. Concluímos: 1. O modelo de CHEN (1973) se aplica ao estudo do transporte de sedimentos fluvial, permitindo a indicação dos pontos de erosão e assoreamento; 2. Os eventos de cheia têm uma grande influência no transporte de sedimentos ao longo do rio. / The transports of fluvial sediments constitutes a complex phenomenon in which innumerable variables are involved. The construction of dams increased the interest in understanding hydraulic effects of this type of work over the river. The retention of sediments in the reservoir formed by the dam and the erosion caused by the contained water can result on disastrous effects to the fluvial system. The use of mathematical models to represent nature and study the sediments transportation phenomenon has been improved. The objective of this work was to evaluate the consequences of dam constructions in the rivers through the application of hydraulic formulas for water and sediments movements in the form of computers algorithms. For the study of sediments transportation in natural channels it was used the model developed by CHEN (1973) while for the analyses of the sediments load capacity in function of the flow and section characteristics was applied the model of TOFFALETI (1969). It was fulfilled one study case with the application of mathematical models for the Castanhão dam, in Ceará state. The use of flood events hydrological regime for the reservoir, with a return period of 10, 20, 25, 50, 100, and 1000 years, indicate an stressed erosion up to 1,00 m of depth right after the dam. The stabilization of the transport phenomenon was estimated at a distance of 10,0 Km after the work (the dam). However the average tributary flows and flows lower than 100 m3/s do not seem to have effect over the fluvial morphology. We conclude: 1. CHEN\'s 1973 model applies to the study of fluvial sediments transportation, allowing the indication of degradation and aggradation points; 2. The flood events have great influence over the sediments transportation along the river.

Durante a exploração de uma mina, vários impactos são causados no meio ambiente, entre eles a geração da drenagem ácida de minas (DAM), que consiste da exposição de minerais sulfetados ao ar, água e microorganismos do tipo ferroxidantes, apresentando reações de oxidação e formação de ácido sulfúrico solubilizando metais ali presentes contaminando o solo e as águas. O objetivo deste trabalho de pesquisa foi estudar uma solução tecnológica fazendo uso da oxidação avançada com ozônio de metais pesados presentes em efluentes contaminados, em mina de urânio, com especial foco na remoção do manganês. A mina de urânio das Indústrias Nucleares do Brasil INB, em Caldas, Minas Gerais, local de aplicação deste estudo, enfrenta o problema da DAM e tem como principais contaminantes de suas águas superficiais os elementos, alumínio (Al), manganês (Mn), zinco (Zn), ferro (Fe), sulfatos (SO4+2), fluoretos (F-), metais de terras raras, alem do urânio (U) e do tório (Th). Os testes com ozônio realizados em laboratório com os efluentes da INB e in situ, mostraram uma grande eficiência para remoção do ferro, manganês e cério em até 99%. A concentração total de manganês ficou abaixo dos limites estabelecidos pela resolução 430 e 357 do CONAMA. Elementos como neodímio (Nd), lantânio (La) e zinco (Zn) pouco se oxidam com O3. O Al se mantém praticamente inalterado, enquanto que o tório e o urânio decaem, mas com o passar do tempo de ozonização voltam a se concentrar, porém com um valor inferior ao inicial. O precipitado obtido após a ozonização consiste de até 85% de oxido de manganês. A fim de descartar, após a ozonização, o efluente líquido para o ambiente é necessário uma correção do pH, de modo a atender os parâmetros da legislação CONAMA, sendo utilizado 50 a 86% menos reagente (CaOH2), do que as quantidades utilizadas no processo adotado pela INB. / During a mine exploration the environment can be affected by different ways being one of them the mine acid drainage(DAM), that is formed by the exposition of sulpheted minerals to the atmospheric air, water and iron-oxidation microorganisms. This exposition results in oxidation reactions and formation of sulphuric acid that dissolves all kind of metals present at the mineral that will result in the contamination of the ground and waters. The object of this research work is to test a technological solution of the mine acid drainage problem applying ozone advanced oxidation of the heavy metals present at the mine drainage of a uranium mine with special focus in the manganese removal. This study is applied to the material from the uranium mine of the Brazilian Nuclear Industry INB, at Caldas- MG. The INB Industry has serious DAM contamination being the main contaminants of the superficial waters the elements, aluminium (Al), manganese (Mn), zinc (Zn), iron (Fe), sulfates(SO4+2), fluorides(F-), rare earth metals besides uranium (U) and thorium (Th). The Caldas unity is being used as research and testing field for the treatment of areas with environment degradation formed by the mining activity. The ozone testing showed a high efficiency for the removal of iron(Fe), manganese(Mn) and cerium (Ce) up to 99%. The manganese total concentration was reduced to values bellow the ones determined by CONAMA resolution. Elements as neodymium (Nd), zinc (Zn) and lanthamium (La) are also oxidated in presence of ozone but with lower efficiency. The aluminium remained unaffected by the ozone while Thorium and Uranium show an initial decay but at the end present only a concentration slight lower than the initial. The solid material formed after the ozone treatment consists mainly of manganese oxide (85%). In order to dispose, after the ozonization, the liquid efluente to the environment is necessary a pH correction in order to be within the CONAMA legislation, being used less reagent (CaOH2), 50 to 86% less, than the amounts used in the process adopted by INB.

No interior de Goiás foi erguida uma barragem no curso do rio Tocantins para viabilizar a construção da Usina Hidrelétrica de Serra da Mesa, cuja represa resultou em um lago de cerca de 1.780 km2. A referida área abrange, parcialmente, oito municípios daquele estado, e compreende uma região cuja ocupação histórica legou importantes sítios arqueológicos que são hoje testemunhos do período colonial: a ocupação bandeirante, que apresenta importantes vestígios de áreas de mineração, a ocupação agropastoril e antigas vilas e lugarejos. Por se tratar de uma região, na atualidade, pouco dinâmica do ponto de vista econômico, é também muito pouco conhecida a nível nacional. Dessa forma, o patrimônio histórico arqueológico que seria perdido com a formação do lago, passou por um processo de salvamento, cujo resgate foi possibilitado através de um convênio entre FURNAS Centrais Elétricas e a UFMG. O salvamento histórico arqueológico procedeu-se durante três anos ininterruptos de pesquisa de campo, evidenciando um riquíssimo patrimônio cultural, que urge ser divulgado tanto a nível acadêmico quanto para a sociedade brasileira como um todo. / On the countryside of Goias was built a barrier across the waterway of the Tocantins river in order to make feasible the construction of Serra da Mesa Hydroeletric Power Station, whose dam resulted on a lake around 1.780 km long. The mentioned area covers, partly, eight towns fron that state, which are part of a region of historical occupation that represents important archaeological sites that are today testimonies of the colonial period: pioneers occupation which presents important evidences of mining and farming areas and old villages and towns. Furthermore, it is a region nowadays that is not very dynamic according to economical aspects, and not very notable concerning to the whole the country. So that, the historical archaeological patrimony that would be lost with the lake formation, has passed by a process of rescue that was only possible due to an agreement between FURNAS Power Company and UFMG. The historical archaeological rescue happened during a 3-year-non-stop field-work, in which an extremely rich cultural patrimony was found and that it utters to be published not only to reach academic levels but also the Brazilian society in general.

Para atender a legislação ambiental do Conselho Nacional do Meio Ambiente (CONAMA), a Resolução CONAMA 357/2005, é necessário desenvolver metodologias que se aplicam na medição analítica de forma correta e para um controle de qualidade é necessário a aplicação da validação de metodologia. Para atender as exigências legais, o presente trabalho desenvolveu uma metodologia para a identificação de 12 elementos metálicos, tais como: Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na e Ni em águas, avaliando 14 pontos, sendo eles GU000-01 (23°46\'49.6\"S-46°47\'22\"0W), GU000-02 (23°45\'29.5\"S-46°46\'18.7\"W), GU000-03 (23°44\'52.2\"S-46°46\'13.6\"W), GU106-04 (23°44\'44.6\"S-46°45\'25.8\"W), GU000-05 (23°44\'57.5\"S-46°45\'24.2\"W), GU107-06 (23°45\'01.2\"S-46°43\'61.5\"W), GU108-07 (23°43\'64.7\"S-46°43\'42.3\"W), GU000-08 (23°42\'96.9\"S-46°43\'61.2\"W), GU109-09 (23°43\'04.6\"S-46°43\'34.0\"W), GU105-10 (23°42\'89.9\"S-46°44\'68.7\"W), GU108-11 (23°42\'53.4\"S-46°43\'44.9\"W), GU103-12 (23°41\'88.5\"S-46°44\'67.3\"W), GU102-13 (23°41\'58.0\"S-46°43\'57.3\"W), GU000-14 (23°40\'78.2\"S-46°43\'55.0\"W), distribuídos pela Represa Guarapiranga, situada no Estado de São Paulo, aplicando a metodologia validade, realizada com base no guia do Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Orientação sobre Validação de Métodos Analíticos - DOQ-CGCE-008. Foram avaliados os parâmetros: seletividade, faixa de trabalho/linearidade, limites de detecção e quantificação, tendência/recuperação, precisão, robustez e incerteza de medição. Foi utilizado a técnica de espectrometria de Emissão Óptica com Plasma de Argônio (ICP-OES). O teste de seletividade comprovou que a matriz não interfere nas curvas analíticas elaborada; a faixa de trabalho apresentou um comportamento linear, para as amostras com e sem a matriz de interesse, com um coeficiente de correlação (r), entre 0,9965 a 1,0; os limites de detecção e quantificação do método atendem aos valores máximos permitidos pela Resolução CONAMA 357/2005; com os testes de repetitividade e de recuperação o método demonstrou ser preciso e exato, além de robusto. Posteriormente foi estimado uma incerteza de medição do método. A incerteza expandida estimada variou entre 3 e 18% da concentração encontrada. A validação da metodologia permitiu a sua aplicação para a avaliação da distribuição dos 12 elementos, nas águas da represa Guarapiranga. Foram observados valores altos para Ca, Na e K, em todos os pontos de coletas analisados, evidenciando que são os elementos que fazem parte da característica geológica da área. Os elementos Fe e Al obtiveram valores acima da legislação nos pontos da Represa (G000-01, G000-02 e G000-03). Com os testes dos parâmetros para a validação, com os cálculos estatísticos aplicados, foi possível desenvolver e aplicar uma metodologia adequada para o uso pretendido. / To attend the environmental legislation of the National Environmental Council (CONAMA) CONAMAs Resolution 357/2005, it is necessary to develop methodologies that apply the analytical measurement correctly and to a quality control application of the methodology validation is required. To attend legal requirements, this study developed a methodology for identifying 12 metals, such as: Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na and Ni in water in 14 points, being them GU000-01 (23°46\'49.6\"S-46°47\'22\"0W), GU000-02 (23°45\'29.5\"S-46°46\'18.7\"W), GU000-03 (23°44\'52.2\"S-46°46\'13.6\"W), GU106-04 (23°44\'44.6\"S-46°45\'25.8\"W), GU000-05 (23°44\'57.5\"S-46°45\'24.2\"W), GU107-06 (23°45\'01.2\"S-46°43\'61.5\"W), GU108-07 (23°43\'64.7\"S-46°43\'42.3\"W), GU000-08 (23°42\'96.9\"S-46°43\'61.2\"W), GU109-09 (23°43\'04.6\"S-46°43\'34.0\"W), GU105-10 (23°42\'89.9\"S-46°44\'68.7\"W), GU108-11 (23°42\'53.4\"S-46°43\'44.9\"W), GU103-12 (23°41\'88.5\"S-46°44\'67.3\"W), GU102-13 (23°41\'58.0\"S-46°43\'57.3\"W), GU000-14 (23°40\'78.2\"S-46°43\'55.0\"W), distributed by Guarapiranga dam, in the State of São Paulo, applying the methodology of validation based on the National Institute of Metrology, Quality and Technology (INMETRO) guide, \"Guidance on Analytical Methods Validation - DOQCGCE- 008\". The parameters analyzed were: selectivity, working range/linearity, limits of detection and quantification, tendency/recovery, accuracy, robustness and measurement uncertainty. Was used the optical emission with argon plasma spectrometry (ICP-OES) technique. The selectivity test proved that the matrix does not interfere with elaborate analytical curves; the elaborate working range obtained demonstrate a linear behavior for samples with and without the matrix of interest, with a coefficient of correlation (r) between 0,9965 and 1,0; limits of detection and quantification of this method meet the maximum values allowed by CONAMA Resolution 357/2005; with repeatability of tests and recovery method proved to be precise and accurate, and robust. It was subsequently estimated uncertainty of measurement method. The estimated expanded uncertainty varied between 3 and 18% of the concentration found. The validation of the methodology allowed the application for the evaluation of the distribution of 12 elements in Guarapiranga dam waters. Were observed high values for Ca, Na and K, at every point analyzed collections, showing, which are, the elements that are part of the geological characteristic of the area. The iron and aluminum elements obtained values above the law in points Dam (G000-01, G000-02 and G000-03). With the parameters for the validation tests, with the statistical calculations applied, it was possible to develop and apply a methodology appropriate for the intended use.

As obras de desvio de rios para a construção de barragens, embora tenham caráter provisório, são de estrema importância, pois definem como o empreendimento será executado, garantindo segurança à sua construção, dentro de riscos calculados, devendo no entanto ser o mais econômica possível. As estruturas de desvio devem se encaixar no arranjo das estruturas permanentes, podendo ser utilizadas como tal. Este trabalho tem o intuito de apresentar as principais estruturas utilizadas em esquemas de desvio de rios e caracterizar sua utilização e aplicabilidade. Sempre que possível foram apresentados esquemas utilizados na prática ou previstos em projeto, para melhor exemplificar e caracterizar as diversas estruturas e as possíveis soluções para desvio de rios. / Diversion works for dam construction are temporary. Nevertheless, they are extremely important, since they define how the construction is going to be made, and assuring its safety, within calculated risks. But, they have to be as economical as possible. The diversion structures must fit the global arrangement of the project, being in some cases be used as permanent structures. This document has the objective of present the main diversion structures used in diversion works schemes, as well as characterize their utilization and applicability. Whenever possible, it was presented examples of schemes either already used or just previewed on design, to better characterize and exemplify the many structures and possible solutions for river diversion.

A Barragem de Itaipu é uma obra de engenharia de grande importância. Localizada na fronteira entre o Brasil e o Paraguai no Rio Paraná e com coordenadas geográficas aproximadas 25°24\'29\"S, 54°35\'21\"O, ela fornece energia elétrica a estes dois países e deve ser constantemente monitorada de modo a manter níveis de qualidade e segurança. Mais de dois mil instrumentos foram instalados e fornecem dados contínuos sobre diversas características da fundação e estrutura da barragem, incluindo mais de 650 piezômetros. A avaliação de níveis piezométricos em barragens é importante, pois refletem os valores de subpressão que atuam na estrutura da barragem. A utilização de novos métodos em tais análises pode permitir agilidade na tomada de decisões por parte da equipe de segurança de barragens. Dependendo do método aplicado, uma melhor compreensão do fenômeno no tempo e espaço pode ser obtida. Este estudo aplica Redes Neurais Artificiais (RNA) para simular o comportamento dos piezômetros instalados em uma descontinuidade geológica na fundação da Barragem de Itaipu. Ele considera diferentes tipos de dados de entrada em uma Rede Neural Multicamadas e determina a melhor arquitetura de RNA que mais se aproxima da situação real. / Itaipu Dam is an engineering work of high importance. Located at the border between Brazil and Paraguay in the Paraná River and with approximated geographical coordinates 25°24\'29\"S, 54°35\'21\"W, it provides electrical energy to these two countries and has to be constantly monitored in order to maintain its levels of quality and security. Over two thousand instruments have been installed and they provide continuous data about several characteristics of the dam foundation and structure, including more than 650 piezometers. The evaluation of piezometric levels in dams is important for it reflects the values of the uplift pressure that acts on the structure of the dam. The utilization of new methods in such an analysis can provide agility to decisions-taking by the security team of the dam. Depending on the method applied, a better comprehension of the phenomenon in time and space may be achieved. This study employs Artificial Neural Networks (ANN) to simulate the behavior of the piezometers installed in a geological discontinuity in the foundation of Itaipu Dam. It considers different types of entry data in a Multilayer Neural Network and determines the best ANN architecture that is closest to the real situation.

Para atender a legislação ambiental do Conselho Nacional do Meio Ambiente (CONAMA), a Resolução CONAMA 357/2005, é necessário desenvolver metodologias que se aplicam na medição analítica de forma correta e para um controle de qualidade é necessário a aplicação da validação de metodologia. Para atender as exigências legais, o presente trabalho desenvolveu uma metodologia para a identificação de 12 elementos metálicos, tais como: Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na e Ni em águas, avaliando 14 pontos, sendo eles GU000-01 (23°46\'49.6\"S-46°47\'22\"0W), GU000-02 (23°45\'29.5\"S-46°46\'18.7\"W), GU000-03 (23°44\'52.2\"S-46°46\'13.6\"W), GU106-04 (23°44\'44.6\"S-46°45\'25.8\"W), GU000-05 (23°44\'57.5\"S-46°45\'24.2\"W), GU107-06 (23°45\'01.2\"S-46°43\'61.5\"W), GU108-07 (23°43\'64.7\"S-46°43\'42.3\"W), GU000-08 (23°42\'96.9\"S-46°43\'61.2\"W), GU109-09 (23°43\'04.6\"S-46°43\'34.0\"W), GU105-10 (23°42\'89.9\"S-46°44\'68.7\"W), GU108-11 (23°42\'53.4\"S-46°43\'44.9\"W), GU103-12 (23°41\'88.5\"S-46°44\'67.3\"W), GU102-13 (23°41\'58.0\"S-46°43\'57.3\"W), GU000-14 (23°40\'78.2\"S-46°43\'55.0\"W), distribuídos pela Represa Guarapiranga, situada no Estado de São Paulo, aplicando a metodologia validade, realizada com base no guia do Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Orientação sobre Validação de Métodos Analíticos - DOQ-CGCE-008. Foram avaliados os parâmetros: seletividade, faixa de trabalho/linearidade, limites de detecção e quantificação, tendência/recuperação, precisão, robustez e incerteza de medição. Foi utilizado a técnica de espectrometria de Emissão Óptica com Plasma de Argônio (ICP-OES). O teste de seletividade comprovou que a matriz não interfere nas curvas analíticas elaborada; a faixa de trabalho apresentou um comportamento linear, para as amostras com e sem a matriz de interesse, com um coeficiente de correlação (r), entre 0,9965 a 1,0; os limites de detecção e quantificação do método atendem aos valores máximos permitidos pela Resolução CONAMA 357/2005; com os testes de repetitividade e de recuperação o método demonstrou ser preciso e exato, além de robusto. Posteriormente foi estimado uma incerteza de medição do método. A incerteza expandida estimada variou entre 3 e 18% da concentração encontrada. A validação da metodologia permitiu a sua aplicação para a avaliação da distribuição dos 12 elementos, nas águas da represa Guarapiranga. Foram observados valores altos para Ca, Na e K, em todos os pontos de coletas analisados, evidenciando que são os elementos que fazem parte da característica geológica da área. Os elementos Fe e Al obtiveram valores acima da legislação nos pontos da Represa (G000-01, G000-02 e G000-03). Com os testes dos parâmetros para a validação, com os cálculos estatísticos aplicados, foi possível desenvolver e aplicar uma metodologia adequada para o uso pretendido. / To attend the environmental legislation of the National Environmental Council (CONAMA) CONAMAs Resolution 357/2005, it is necessary to develop methodologies that apply the analytical measurement correctly and to a quality control application of the methodology validation is required. To attend legal requirements, this study developed a methodology for identifying 12 metals, such as: Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na and Ni in water in 14 points, being them GU000-01 (23°46\'49.6\"S-46°47\'22\"0W), GU000-02 (23°45\'29.5\"S-46°46\'18.7\"W), GU000-03 (23°44\'52.2\"S-46°46\'13.6\"W), GU106-04 (23°44\'44.6\"S-46°45\'25.8\"W), GU000-05 (23°44\'57.5\"S-46°45\'24.2\"W), GU107-06 (23°45\'01.2\"S-46°43\'61.5\"W), GU108-07 (23°43\'64.7\"S-46°43\'42.3\"W), GU000-08 (23°42\'96.9\"S-46°43\'61.2\"W), GU109-09 (23°43\'04.6\"S-46°43\'34.0\"W), GU105-10 (23°42\'89.9\"S-46°44\'68.7\"W), GU108-11 (23°42\'53.4\"S-46°43\'44.9\"W), GU103-12 (23°41\'88.5\"S-46°44\'67.3\"W), GU102-13 (23°41\'58.0\"S-46°43\'57.3\"W), GU000-14 (23°40\'78.2\"S-46°43\'55.0\"W), distributed by Guarapiranga dam, in the State of São Paulo, applying the methodology of validation based on the National Institute of Metrology, Quality and Technology (INMETRO) guide, \"Guidance on Analytical Methods Validation - DOQCGCE- 008\". The parameters analyzed were: selectivity, working range/linearity, limits of detection and quantification, tendency/recovery, accuracy, robustness and measurement uncertainty. Was used the optical emission with argon plasma spectrometry (ICP-OES) technique. The selectivity test proved that the matrix does not interfere with elaborate analytical curves; the elaborate working range obtained demonstrate a linear behavior for samples with and without the matrix of interest, with a coefficient of correlation (r) between 0,9965 and 1,0; limits of detection and quantification of this method meet the maximum values allowed by CONAMA Resolution 357/2005; with repeatability of tests and recovery method proved to be precise and accurate, and robust. It was subsequently estimated uncertainty of measurement method. The estimated expanded uncertainty varied between 3 and 18% of the concentration found. The validation of the methodology allowed the application for the evaluation of the distribution of 12 elements in Guarapiranga dam waters. Were observed high values for Ca, Na and K, at every point analyzed collections, showing, which are, the elements that are part of the geological characteristic of the area. The iron and aluminum elements obtained values above the law in points Dam (G000-01, G000-02 and G000-03). With the parameters for the validation tests, with the statistical calculations applied, it was possible to develop and apply a methodology appropriate for the intended use.