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Lagos de mina: alternativa para abastecimento público? / Mine lakes: alternative for public supply?Silveira, Pedro Henrique Vogt 11 March 2019 (has links)
Eventos climáticos localizados e fora dos padrões, que promovam longos períodos de estiagem, podem acarretar impactantes crises hídricas em sistemas de abastecimento de água saturados ou próximos dos limites de operação. A necessidade de projetos sustentáveis de longo prazo é eminente, porém soluções emergenciais são necessárias para superar esses períodos. Municipios onde a atividade mineira é atuante podem esperar ao findar das suas operações a formação de cenários atípicos em sua paisagem, como grandes bacias resultantes da remoção do minério. Essas bacias podem ter destinos nobres para a sociedade se o lençol freático estiver aflorante, não apenas como função paisagística, uma vez que concentram volumes consideráveis de água. Os lagos de minas formados podem oferecer a possibilidade de captação de água para potabilidade em períodos de crises hídricas. Este trabalho apresenta volumes expressivos na modelagem matemática de corpos hídricos, estimada pelo nível do lençol freático de poços tubulares profundos, na Região metropolitana de São Paulo, em cenários atuais e possíveis de minerações ativas ou finalizadas. / Localized and non-standard climate events that promote long periods of drought can lead to impact water crises in saturated water supply systems or close to operating limits. The need for sustainable long-term projects is imminent, but emergency solutions are needed to overcome these periods. Cities where mining activity is active can expect at the end of their operations the formation of atypical scenarios in their landscape, such as end-pit mines resulting from the removal of ore. These basins may have noble destinations for society if the groundwater surface is outcropped, not only as a landscape function, since they concentrate considerable volumes of water. The lakes formed mines can offer the possibility of abstraction of water for potability in periods of water crises. This work presents significant volumes in the mathematical modeling of water bodies, estimated by the level of the groundwater table obtained by deep tubular wells, in the metropolitan region of São Paulo, in current and possible scenarios of active or finished mining.
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Internal mixing in a mine lakeHuber, Anita January 2007 (has links)
[Truncated abstract] Mine lakes are a water body created after an open-cut mine ceases operating. The lakes develop in the former mine-pit due to the combination of groundwater inflow, surface run-off and, in some cases, due to rapid filling from river diversion. While potentially valuable water resources, these lakes often have poor water quality and managing the water body is an important part of the overall process of mine site rehabilitation. As mine lakes form in man-made pits, they have a bathymetry that is typically quite distinct from natural lakes and this can, in turn, strongly influence the hydrodynamics and hence the water quality of the water body. Despite the potential importance of these water bodies, there have been very few studies on the hydrodynamics of mine lakes. This study describes a field investigation of the hydrodynamics of a former coal mine lake, Lake Kepwari, in south-western Western Australia. In particular, this study examines the hydrodynamic processes in both the surface mixing layers and the internal mixing in the density stratified lake. Wind sheltering in the surface mixing layer occurs due to the presence of the steep walls and lake embankments. A week long field experiment was conducted in December 2003 using a combination of moored thermistor chains with meteorological stations and the deployment of rapid vertical profiling turbulent microstructure instruments and CTD drops from two boats operating on the lake. ... Simulations indicated that inclusion of a site specific sheltering effect, based on the results of the field campaign, significantly improved the models‘ performance in capturing the surface mixed layer deepening associated with episodic strong wind events that occur on the lake. Considerable internal mixing was indicated by the high dissipation rates observed, particularly near the boundaries. Large basin-wide diffusivities were also calculated from the heat budget method over long periods, showed a consistency with time, and were slightly higher in summer than during the Autumn Winter period. Although light, there are persistent winds over the lake and yet little basin-scale internal wave activity or seiching. It is hypothesized that any seiching motion was rapidly damped by strong mixing over the hydraulically rough bathymetry bathymetry created by the remnant benches from the open cut mining operation itself. This boundary mixing, in turn, drives secondary relaxation currents that transport mixed fluid from the boundaries to the interior, resulting in high effective basin-wide diffusivities. A simple boundary mixing model is proposed to describe this process.
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Alternativas para requalificação de áreas de mineração e lagos de cava de mineração de areia : Estudo de caso - Lago Guaraciaba (Santo André, SP)Alves, Viviane Pereira January 2016 (has links)
Orientadora: Prof.ª Dra Roseli Frederigi Benassi / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, 2016. / Este trabalho teve como objetivo estudar as condições biofísicas, físico-químicas e socioambientais do parque Ecológico Guaraciaba e lago Guaraciaba (Santo André - SP), formado em área de mineração abandonada. A metodologia utilizada contemplou: (1) revisão bibliográfica, onde foi feito o levantamento dos principais trabalhos sobre o tema e pesquisas que identificam áreas degradadas pela mineração; a formação de lagos nestas áreas; áreas reabilitadas para usos diversos; e a legislação vigente; (2) análise da qualidade da água do lago, através de dados secundários; (3) levantamento de variáveis climáticas - temperatura e umidade relativa, para posterior aplicação do método expedito que permitiu analisar a influência do Parque Ecológico Guaraciaba e o respectivo lago no microclima local; (4) análise de alternativas para áreas degradadas pela mineração; (5) análise da percepção dos moradores da região do parque, através de questionário semiestruturado e biomapa, o que tornou possível observar como os mesmos descrevem a paisagem do parque Guaraciaba, sobretudo do lago Guaraciaba; e (6) propostas de requalificação ao parque ecológico Guaraciaba. Constatou-se que a falta de planejamento, desde o início até o encerramento da atividade mineradora, suscitou diversos conflitos, sobretudo socioambientais. O parque atualmente apresenta situação de abandono e o lago apresenta risco aos frequentadores que o utilizam para banho de forma irregular. Abastecido pela contribuição de aquíferos, precipitação pluviométrica direta e o escoamento superficial, a água do lago não atende os padrões de qualidade estabelecidos na resolução Conama 357/05 para corpos hídricos de classe 1, embora, questione-se o método de coleta das amostras. O lago pode ser considerado um reservatório de água contribuindo com o volume total captado pelo município. O parque possui potencial para oferecer convivência social, prática de esportes e exercícios físicos, espaço para recreação, educação ambiental e cultura aliado a preservação ambiental, além de contribuir para a valorização imobiliária e estimulação do comércio na região circunvizinha, contribui ainda amenizando o desconforto térmico causado pela formação de ilhas de calor. Conclui-se que é necessário investir mais esforços e estratégias de gestão ambiental para otimizar a conservação da área do parque Guaraciaba para a manutenção das áreas verde, bem como do bem-estar da população. / This academic work aims to study the biophysical, physicochemical conditions and socio-environmental responsibility of Guaraciaba ecological park and Guaraciaba lake (Santo Andre - SP) formed in abandoned mining area. The methodology used included (1) literature review that entailed research to identify areas degraded by mining, the formation of lakes in these areas and rehabilitation of areas for various uses and also legislation; (2) analysis of the water quality of lake via secondary data (3); survey of climatic variables (temperature, rainfall and relative humidity) for later application of weather expeditious method to consider the influence of Guaraciaba lake in the local microclimate; (4) analysis of alternatives for use of areas degraded by mining; (5) application of semi-structured questionnaire to various groups of people involved or not with the Guaraciaba Park and biomap where we can observe how the locals describe the landscape of Guaraciaba Park, especially the Guaraciaba lake and (6) requalification proposals to the ecological park Guaraciaba. It was found that the lack of planning from the beginning to the closure of mining activity may raise many conflicts, especially social and environmental. It was found that deficiency of planning from the beginning to the closure of mining activity has raised several conflicts, especially environmental. The park currently has abandonment situation and the lake bring a risk to the users of bath erratically. Fueled by contribution of aquifers, rainfall precipitation direct and surface runoff, the lake water does not meet the quality standards set out in Resolution CONAMA 357/05 water bodies of class I, allthough ask yourself the Collection Method of Samples. The lake can be considered a water tank contributing to the total volume collected municipality. The park has the potential offer social life, the practice of sports and physical exercises, space recreation, environmental education and culture combined with environmental preservation, in addition to contributing to the real estate appreciation and stimulation of trade in the region of the surrounding region, contributes still easing the thermal discomfort caused by the formation of heat islands. The conclusion is that necessary to invest more efforts and environmental management strategies to optimize the conservation of Guaraciaba Park and maintenance of green areas, as well as the population welfare.
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