180 resultados para Barragem
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In the contemporary world to the deterioration of semi-arid areas of the planet has been the focus of media attention and the scientific community. Brazil has a semiarid, considered the most problematic of the world, either by pressure from physical factors, whether as a result of misguided public policies, has over time been suffering from the consequences of a deterioration that expands over the years. Methodologies, that amidst the problems of semi-arid, come against the deteriorating local, have a good chance to be reapplied in other contexts around the world. This research, based on methodological model for analyzing environmental deterioration, introduced and examined the applicability of the methodology in the semi-arid region of Rio Grande do Norte - Brazil. Although the results provide guidelines for the introduction of underground dams, the application of the methodology was ineffective, given the high rates of forest cover that gave low values for the physical diagnosis conservationist
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The management of water resources in the river basin level, as it defines the Law nº 9433/97, requires the effective knowledge of the processes of hydrological basin, resulting from studies based on consistent series of hydrological data that reflect the characteristics of the basin. In this context, the objective of this work was to develop the modeling of catchment basin of the river Jundiaí - RN and carry out the study of attenuation of a flood of the dam Tabatinga, by means of a monitoring project of hydrological data and climatology of the basin, with a view to promoting the development of research activities by applying methodologies unified and appropriate for the assessment of hydrological studies in the transition region of the semiarid and the forest zone on the coast of Rio Grande do Norte. For the study of the hydrological characteristics of the basin was conducted the automatic design of the basin of the river Jundiaí, with the aid of programs of geoprocessing, was adopted a hydrological model daily, the NRCS, which is a model determined and concentrated. For the use of this model was necessary to determine some parameters that are used in this model, as the Curve Number. Having in mind that this is the first study that is being conducted in the basin with the employment of this model, it was made sensitivity analysis of the results of this model from the adoption of different values of CN, situated within a range appropriate to the conditions of use, occupation and the nature of the soil of this basin. As the objective of this study was also developing a simulation model of the operation of the Tabatinga dam and with this flood control caused in the city of Macaíba, it was developed a mathematical model of fluid balance, developed to be used in Microsoft Excel. The simulation was conducted in two phases: the first step was promoted the water balance daily that allowed the analysis of the sensitivity of the model in relation to the volume of waiting, as well as the determination of the period of greatest discharges daily averages. From this point, it was assumed for the second stage, which was in the determination of the hydrograph of discharges effluent slots, that was determined by means of the fluid balance time, on the basis of the discharges effluents generated by a mathematical equation whose parameters were adjusted according to the hydrograph daily. Through the analyzes it was realized that the dam Tabatinga only has how to carry out the attenuation of floods through the regularization of the volume of waiting, with this there is a loss of approximately 56.5% on storage capacity of this dam, because for causing the attenuation effect of filled the shell of this dam has to remain more than 5m below the level of the sill, representing at least 50.582.927m3. The results obtained with the modeling represents a first step in the direction of improving the level of hydrological information about the behavior of the basins of the semiarid. In order to monitor quantitatively the hydrographic basin of the river Jundiaí will be necessary to install a rain gauge register, next to the Tabatinga dam and a pressure transducer, for regular measurements of flow in the reservoir of the dam. The climatological data will be collected in full automatic weather station installed in Agricultural School Jundiaí
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The potentially toxic cyanobacterial blooms in water bodies are spread across the globe, resulting in the loss of water quality and adverse effects on human health. In arid and semiarid regions, the hydrologic regime characterized by an annual cycle of drought and rain, change the volume and the retention time of the reservoir. Such changes affect the limnological characteristics and causing changes in composition and biomass community of cyanobacteria. The reservoir Cruzeta (Zmax = 8.7 m) is a eutrophic water supply source located in the semiarid tropical (Northeast Brazil). Raised the hypothesis that the hydrological regime of semi-arid tropical is a determining factor in the availability of resources in eutrophic water sources, which influences the composition of dominant species of cyanobacteria. The aim of this study was to analyze the changes in biomass and species composition of cyanobacteria for two annual hydrological cycles and evaluate factors drivers. The study was divided into five distinct periods (dry 2010, rain 2011, dry 2011, rain 2012, dry 2012). The dominant group found in all periods was Cyanobacteria (99% of total biomass), which contributed to the low diversity. The filamentous species Cylindrospermopsis raciborskii was present at both points in almost every study. The colonial species Microcystis panniformis and Sphaerocavum brasiliensis dominated only in periods with lower volumes of water. The diatoms contribute more to the biomass during the period of severe drought. The point near the dam (P1) had phytoplankton biomass larger than the point near the tributary (P2). The dominant species of colonial cyanobacteria lasted until the overflow in P1, and P2 this dominance was until the first rains. The redundancy analysis indicated that physical factors such as light availability and water level were the main factors driving the seasonal succession of phytoplankton. The composition of phytoplankton in spring was alternated by species of filamentous cyanobacteria in conditions of poor stability of the water column, such as Cylindrospermopsis raciborskii, and colonial species under conditions of high stability of the water column, such as Microcystis panniformis and Sphaerocavum brasiliensis. The extremes of torrential rains and severe droughts, governed by the hydrological regime of the semi-arid region led to the availability of resources in the watershed, directing the spatial and temporal dynamics of phytoplankton in the reservoir Cruzeta
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As áreas de empréstimo em hidrelétricas são as áreas remanescentes da construção da fundação da barragem e podem ser consideradas áreas degradadas, pois delas foram retirados os horizontes superficiais do solo. Este trabalho teve como objetivo estudar a recuperação de um Latossolo Vermelho distrófico, degradado por construção civil (Usina Hidrelétrica de Ilha Solteira-SP), por meio de adubação verde e aplicação de calagem e gessagem. Os tratamentos constituíram-se de: testemunha (solo mobilizado e vegetação espontânea); mucuna-preta e guandu até 1994. Depois foram substituídos por feijão-de-porco; calcário + mucuna-preta; calcário + guandu até 1994. Nova substituição foi feita por feijão-de-porco; calcário + gesso + mucuna-preta e calcário + gesso + guandu até 1994. Outra substituição foi feita por feijão-de-porco. Esses tratamentos foram estabelecidos em blocos casualizados com quatro repetições: após quatro anos com os adubos verdes, um ano com milho, um ano com aveia-preta e dois anos com braquiária. Foram avaliados: pH, teores de Ca2+, Mg2+, P, K, capacidade de troca catiônica, saturação por bases e teor de matéria orgânica. Os tratamentos adotados estão recuperando os atributos químicos do solo degradado, e a mucuna-preta apresentou os melhores resultados, quando comparada ao guandu e feijão-de-porco. Os efeitos da recuperação dos atributos químicos do solo alcançaram a profundidade de 0,0-0,2 m. As técnicas adotadas para recuperação desses atributos químicos (adubação verde, calagem e gessagem) no primeiro ano atingiram a profundidade do solo de 0,0-0,1 m e, somente após cinco anos, de 0,0-0,2 m.
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Water is considered an essential right to life, besides being a determinant of economic development and social welfare, represented by both the quantity available, and the quality. In semi-arid Northeast, droughts occurring on a regular basis combined with human activities, aggravate the situation regarding the conservation of water resources in this area. To alleviate this condition is common to construction of artificial reservoirs, such as reservoirs and dams. As in natural aquatic environments, these reservoirs are potential sites for the proliferation, growth and development of diverse biological communities, whether of animals, plants and microorganisms. Research on the composition and ecology of these communities, especially microbial, are still restricted. One of the least studied groups in these environments are free-living protozoa, which over time have been neglected and after discoveries about its various functions in the aquatic ecosystem are beginning to receive more attention from scholars. They are, in quantitative terms, the most important consumers of microorganisms (mainly bacteria and algae) in aquatic environments, and therefore control the abundance of these. They may therefore influence the structure of the aquatic food chain in terms of species composition, abundance, biomass and biodiversity. Despite the recognition of the importance of protozoa in the final of the trophic transfer in aquatic environments, there are few data and, in general, are still precarious knowledge of them. Given the importance of protozoa in aquatic environments and the paucity of research on this group, especially in the state of Rio Grande do Norte, the present study aimed at identifying the genus and species of free-living protozoa that are present in the Armando Ribeiro Gonçalves Dam as well as to relate the occurrence and dynamics of the trophic conditions in the environment in which they are inserted, in order to support the hypothesis that species that are in these environments can serve to indicate the water quality. We observed the presence of 65 taxa of free-living protozoa, of which 29 were identified at the species level. There was a similarity space in taxonomic composition of protozoa, suggesting a possible regulation of this type of community for limnological variables other than those studied in this work (chlorophyll a, pH, temperature). Although it was aimed to analyze the conceptions of teachers and students from nearby towns Dam Armando Ribeiro Gonçalves, on issues relating to water quality and the role of protozoa. For this, we applied questionnaires with teachers and pupils of public schools of San Rafael and Itajá. It was concluded that teachers and students recognize the multi-dam Armando Ribeiro Gonçalves, although unaware of important aspects of the dynamics and ecology of this environment. Conceptions of teachers and students are matched at various times, especially with regard to waterborne diseases. In an attempt to identify possible misconceptions about the knowledge of the protozoa, assuming that these organisms have neglected their ecological role, and are seen as only, disease, a study was done with teachers and students, following a particular methodology that allowed look so clear and precise results. It was clear that knowledge about the free-living protozoa is still quite limited. The alternative conceptions that were found show a direct relation of protozoans and diseases. From the data obtained by these studies, we planned a series of science communication activities, environmental education and health education in schools close to study environments in order to promote a didactic transposition of accumulated knowledge about these organisms, favoring continuing education of teachers and the increase of information to the local community through the knowledge of biodiversity and ecology of these organisms. Moreover, the results found in this study and reflections on it that led to propose the elaboration of a book Readers with an emphasis on the group of freeliving protozoa in the populations for use in public schools in the region where it was developed the semiarid work
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The conservation of natural resources is essential and constitutes the main subject of many researches, which characterize important aspects concerning the environmental alterations in the ground, water, landscape and socioeconomic information. This study aimed to investigate the anthropogenic input of heavy metals in the environment, in the area of the Parelhas dump site and in part of the Seridó River and to determine the concentration of heavy metals in the sediments. This can result in risk to the environment and human health. In addition, we sought to establish the socioeconomic profile of rural communities adjacent to Seridó River and to comprehend the perception of these dwellers about the changes in the places they live. The area of this study is located in the city of Parelhas/RN, in the centralsouthern part of the State, in the micro-region of the Oriental Seridó. This area comprehends the place where the dump site is located, next to RN 086, the Caldeirão dam, the Quintos river called by local citizens Caldeirão creek and part of Seridó river, perpetuated by the Boqueirão dam, which crosses the city and it includes the rural communities of Almas, Domingas, Sussuarana II and Colonos. Regarding the study with bottom sediments, the samples were collected and taken to the laboratory of geochemistry, where they were dried, sieved, weighted and submitted to weak acid attack. The analysis of heavy metals was held by Atomic Absorption Spectrophotometer - Flame AAS. We applied 23 closed questionnaires constituted by 38 questions to collect informations in the rural communities, oriented to establish the socioeconomic profile and the environmental perception of the participants. The participants were distributed in the communities of Almas (1), Domingas (2), Sussuarana II (10) and Colonos (10). Most of them presented similar socioeconomic profiles. They are from 45 to 60 years old and live in these localities for 20 to 30 years or more. The families are composed by 3 or 4 people; the agriculture is the main activity, livestock is the secondary and 48% of them earn the minimal wage. Regarding the environmental perception, the participants can realize some changes in vegetation, soil, water and landscape. People living longer in the community, and with more years of experience on the local reality can perceive the depletion of the soil, pastures and changes in the landscape. These changes portray how the place was previously and what it represents today. The perception of these changes, besides the environmental ones, includes others concerning the increasing number of dwellers in the last years, as well as the number of houses. The changes happened through activities developed by the dwellers over the years, including agricultural practices, livestock, grass planting and even the cultivation of cotton. The study provided the acquisition of new data about the environmental reality of this region. It can subsidize the definition of public policies that can be implemented from the perspective of conservation of water resources and of the coexistence and survival of man in the semi-arid
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The monitoring of Earth dam makes use of visual inspection and instrumentation to identify and characterize the deterioration that compromises the security of earth dams and associated structures. The visual inspection is subjective and can lead to misinterpretation or omission of important information and, some problems are detected too late. The instrumentation are efficient but certain technical or operational issues can cause restrictions. Thereby, visual inspections and instrumentation can lead to a lack of information. Geophysics offers consolidated, low-cost methods that are non-invasive, non-destructive and low cost. They have a strong potential and can be used assisting instrumentation. In the case that a visual inspection and strumentation does not provide all the necessary information, geophysical methods would provide more complete and relevant information. In order to test these theories, geophysical acquisitions were performed using Georadar (GPR), Electric resistivity, Seismic refraction, and Refraction Microtremor (ReMi) on the dike of the dam in Sant Llorenç de Montgai, located in the province of Lleida, 145 km from Barcelona, Catalonia. The results confirmed that the geophysical methods used each responded satisfactorily to the conditions of the earth dike, the anomalies present and the geological features found, such as alluvium and carbonate and evaporite rocks. It has also been confirmed that these methods, when used in an integrated manner, are able to reduce the ambiguities in individual interpretations. They facilitate improved imaging of the interior dikes and of major geological features, thus inspecting the massif and its foundation. Consequently, the results obtained in this study demonstrated that these geophysical methods are sufficiently effective for inspecting earth dams and they are an important tool in the instrumentation and visual inspection of the security of the dams
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This research talks about the insertion of the borough Ipanguaçu-RN on the agricultural globalization process from 1979 to 2003. At the first moment (1979-1992) with the construction of the Açu´s barrage and the entry of agricultural national enterprises and secondly (1993-2003) with the entry of the multinational Del Monte Fresh Produce enterprise. During all this insertion period the impacts on the local land market. To make the research operational, it was tried to analyze documents of the local registry office and all the local, national and international bibliography about this issue during all the study period. Furthermore, interviews were made. At the ending of this thesis, the results show intensification of the agricultural capitalization on this borough, changing of the productive axis which heads to the external market and the land concentration of this borough. It was concluded that the insertion of this borough in the globalization system will increase the external intervention on Ipanguaçu blocking, then, the access if the local population to the land
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Aim: To analyze the composition, species richness and spatial distribution of the fish fauna in the area under influence of the Salto Grande Reservoir; Methods: Fish were caught every two months from November/05 to October/06, using gill nets, seining nets and sieve; Results: It was registered 67 fish species, 1,964 individuals and 146.2 kg, representing CPUEn of 1,964 and CPUEb of 278 kg. The most representative orders were Characiformes, with 29 species, Siluriformes (21 species) and Perciformes (11 species) Nine non-native species were registered. The most abundant species in the reservoir were Astyanax altiparanae, Steindachnerina insculpta and Acestrorhynchus lacustris, indicating the predominance of medium and small fishes in this reservoir. The dendrogram of similarity separated the Dam and Pedra Branca stretches from Pardo River Mouth, indicating differences in the assemblages. The species turnover among the stretches was demonstrated by the beta diversity, which may be related to the diversity of habitat; Conclusions: Although being a small reservoir, it displays great habitat diversity, reflecting in the composition and structure of fish assemblages.
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Foi investigada a correlação entre nível hidrológico, pluviosidade e temperatura e reprodução de peixes num trecho lótico do rio Grande, abaixo da barragem de Volta Grande. Para a captura, realizada com redes de espera, foram feitas seis amostragens bimestrais de abril de 1998 a fevereiro de 1999. As gônadas foram classificadas de acordo com o estádio de maturação e aquelas maduras ou esgotadas foram correlacionadas com as variáveis ambientais. A maioria das espécies apresentou reprodução sazonal, entre outubro e fevereiro. A freqüência relativa bimestral de gônadas maduras ou esgotadas de todos os exemplares agrupados foi correlacionada significativamente com pluviosidade (Spearman r = 0,94, p = 0,005) e temperatura do ar (r = 0,84, p = 0,036), mostrando a importância destes fatores no controle do ciclo reprodutivo dos peixes. Devido à barragem, o nível hidrológico pouco variou e não foi encontrada correlação significativa entre reprodução e nível hidrológico (r = -0,43, p = 0,396).
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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A variabilidade anual da produção fotossintética (PP) pelo fitoplâncton na zona da barragem da Represa de Jurumirim (São Paulo, Brasil) foi medida após um estudo no período de três anos sucessivos, com o objetivo de identificar padrões recorrentes e suas causas. Medidas da variabilidade da PP em escala diária foram obtidas em dois períodos do ano (estações seca e chuvosa). Nenhum padrão recorrente foi verificado nos dados de PP, visto não haver relação de sua variabilidade com nenhum fator hidrológico (precipitação, nível e vazão de água e washout) nem, aparentemente, com as condições nutritivas da água. A análise de componentes principais revelou que a PP e a taxa de assimilação foram mais elevadas na época do ano em que o conteúdo de PO4(3-) e N-NH4+ foi mais baixo e quando as razões Z EU/Z MIX foram mais elevadas. A produtividade primária/área pode ser estimada pela razão entre a produtividade volumétrica máxima e o coeficiente de extinção vertical da luz. Entretanto, a biomassa integrada na Z EU foi um pobre preditor da produtividade primária/área. Nenhuma correlação foi encontrada entre a temperatura da água com a produtividade primária (por área e volumétrica máxima). em conseqüência, o estudo da PP em três anos sucessivos mostrou que o padrão de variabilidade é tipicamente caótico. em relação às medidas de curta duração, maior PP foi encontrada na estação seca do que na chuvosa. em ambos os períodos, a variabilidade da PP (por área) foi de aproximadamente 35-40%. O padrão foi atribuído não somente à variação na concentração dos nutrientes mas também à magnitude de penetração de luz na água associado ao regime de circulação. Um comentário sobre a relação entre produção primária pelo fitoplâncton com produção pesqueira é também apresentada.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)