As sub-bacias Rincón Blanco e Cerro Puntudo são depocentros pertencente à parte norte da Bacia de Cuyo, que está exposta em um terreno alóctone da Pre- Cordilheira, Andes Centrais, Argentina. Este terreno é descrito como parte do Supercontinente Laurentia, que foi adicionado ao protomargin Gondwana durante o Oroviciano. A bacia, que é um rifte Triássico, foi preenchida predominantemente de sedimentos clásticos e material vulcânico, vulcanclástico e piroclástico em ambiente continental, e é composta de vários meio-grabens assimétricos conectados por zonas de acomodação. Análises isotópicas de UPb e Lu-Hf em zircão foram realizadas nas unidades do embasamento, rochas vulcanoclásticas rochas e tufos de ambas as sub-bacias triássicas. O embasamento, representado por rochas vulcânicas andesíticas, foi datado em 269,9 ± 2,9 Ma com idades modelo de Hf de 1,34 a 1,60 bilhões de anos (Ga). As rochas vulcanoclásticas são compostas por zircões com idades de 238 a 1433 milhões de anos (Ma), com moda principal no Permiano-Triássico e Esteniano (1,0 a 1,2 Ga). Riolito e tufos triássicos formaram-se entre 246 e 230 Ma e têm idades modelo Hf variando de 1,02 a 1,50 Ga. Assim, as rochas vulcanoclásticas presentes apresentam dominantemente idades mesoproterozóicas, as quais são correlacionados ao Evento Grenviliano. Alguns grãos de zircão mostram idades modelo Hf paleoproterozóicas, que são interpretadas como sugestiva proveniência do Supercontinente Gondwana. A presença de idades mesoproterozoica dominante sugere que o magmatismo ácido associado a Bacia do Cuyo e o próprio Terreno Alóctono Cuyano tenha um embasamente Grenviliano. / The sub-basins Rincón Blanco and Cerro Puntudo are depocenter belonging to the northern part of the Cuyo Basin, exposed in an allochthonous terrane of Laurentia that was added to the Gondwana protomargin and now exposed in the Precordillera Argentina. The rift basin was filled predominantly of pyroclastic and continental clastic sediments, and is composed of many asymmetric grabens half-linked by accommodation zones. U-Pb and Lu-Hf zircon isotope analyses were carried out in the basement units and volcanoclastic rocks and tuffs of both Triassic sub-basins. Basement rocks were dated at 269.9±2.9 Ma with Hf model ages 1.34 to 1.60 Ga. The volcanoclastic rocks contain zircons crystallized from 238 Ma to 1433 Ma with main peak at Permian-Triassic and Stenian (1.0 to 1.2 Ga). The Triassic rhyolite and tuffs formed between 246 and 230 Ma and have Hf model ages ranging from 1.02 to 1.50 Ga. Indeed, the volcanoclastic rocks present dominant Mesoproterozoic ages, mostly correlated to the Grenvillian. Some zircon grains show Hf Paleoproterozoic model ages which are interpreted to be part of Gondwana cratonic areas. The presence of dominant Mesoproteorzoic favored the hypotheses of a Grevillian basement for the related acid magmatism of the Cuyo Basin and allocthonous Cuyan Terrane.

Made available in DSpace on 2017-07-20T13:41:57Z (GMT). No. of bitstreams: 1 Lorena Freitas.pdf: 3656335 bytes, checksum: a73d6d7a3f37451fcd4d03cfd427665a (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Anthropogenic activities developed in watersheds affects water resources, decreasing its quality and quantity. This work was developed in the São João river watershed, supply source in the city of Carambeí (PR), in order to understand the effects of land use and occupation in water quality. Water samples were collected for nine months, from April to December 2015, in two sub-basins, a predominantly native vegetation (sub-basin 1 - 69.8%) and the other with agricultural predominance (sub-basin 2 - 54.1%). The parameters analyzed were dissolved oxygen (DO), temperature, electrical conductivity (EC), pH, total dissolved solids (TDS), turbidity, apparent color, biochemical oxygen demand (BOD), total nitrogen (total-N), total phosphorus (total-P), total coliform (TC) and fecal (FC). Analysis of variance (ANOVA) confirmed that there are significant differences between the collection points. The sub-basin 2 had the lowest averages for DO (6.2 mg L-1) and pH (6.9) and highest averages for temperature (17.8 ° C), color (68.1), turbidity (26.5 UNT) TDS (56.6 mg L-1), EC (76.1 μS cm-1), total-P (1.7 mg L-1), total-N (2.1 mg L-1), BOD (18.2mg L-1) and FC (1451.0 MPN) and presented values above the set by CONAMA nº 357 for total-P, BOD and FC. The sub-basin 1 had values above the set by CONAMA nº 357 for BOD and total-P and high values total-N (1.1 mg L-1). The Pearson correlation analysis showed that there was influence of accumulated rainfall in the sub-basin 1 for turbidity (- 0.70), TDS (- 0.88) and EC (- 0.74) and in the sub-basin 2 to total-N (0.66) and FC (0.67). The atmospheric temperature showed positive correlations with the water temperature, which influenced the parameters in the two sub-basins directly or indirectly, both in maximum, medium and minimum temperatures. The OD showed an inverse relationship with the atmospheric temperature in the two sub-basins. The pH in point 2 had a negative correlation with the atmospheric temperature, and the turbidity point 1 (- 0.67 min. temp. two days). The color had a negative correlation with atmospheric temperature in the two sub-basins. The EC (0.74 min. temp. two days) and CF (0.74 temp. min. two days) showed a positive correlation with atmospheric temperature to the point 2. In general, it was found that the water quality of the sub-basin 2 is strongly influenced by agriculture, coupled with the lack of riparian vegetation and fertilization with animal manure. The sub-basin 1 showed improved water quality due to a higher percentage of native vegetation. However, the lack of Permanent Preservation Area in the springs and farms located upstream of the basin affect water quality. / Atividades antrópicas desenvolvidas em bacias hidrográficas podem afetar os recursos hídricos, diminuindo sua disponibilidade. O presente trabalho foi desenvolvido na bacia hidrográfica do rio São João, manancial de abastecimento do município de Carambeí (PR), a fim de compreender os efeitos do uso e ocupação do solo na qualidade da água. Foram coletadas amostras de água durante nove meses, de abril a dezembro de 2015, em duas sub-bacias, uma com predomínio de vegetação nativa (sub-bacia 1 - 69,8%) e outra com predomínio de agricultura (sub-bacia 2 - 54,1%). Os parâmetros analisados foram oxigênio dissolvido (OD), temperatura, condutividade elétrica (CE), pH, sólidos totais dissolvidos (STD), turbidez, cor aparente, demanda bioquímica de oxigênio (DBO), nitrogênio total (N-total), fósforo total (P-total), coliformes totais (CT) e fecais (CF). A análise de variância (ANOVA) confirmou que existem diferenças significativas entre os pontos de coleta. A sub-bacia 2 apresentou as menores médias para OD (6,2 mg L-1) e pH (6,9) e maiores médias para temperatura (17,8 ºC), cor (68,1), turbidez (26,5 UNT), STD (56,6 mg L-1), CE (76,1 μS cm-1), P-total (1,7 mg L-1), N-total (2,1 mg L-1), DBO (18,2 mg L-1) e CF (1451,0 NMP) e apresentou valores acima do estabelecido pelo CONAMA nº 357 para rios de água doce de classe II para P-total, DBO e CF. A sub-bacia 1 apresentou valores acima do estabelecido pelo CONAMA nº 357 para DBO e P-total e valores elevados de N-total (1,1 mg L-1). A análise de correlação de Pearson demonstrou haver influencia da precipitação acumulada na sub-bacia 1 para turbidez (- 0,70), STD (- 0,88) e CE (- 0,74) e na sub-bacia 2 para N-total (0,66) e CF (0,67). A temperatura atmosférica demonstrou correlações positivas com a temperatura da água, devido à variações sazonais naturais, o que influenciou os parâmetros nas duas sub-bacias, direta ou indiretamente, tanto nas temperaturas máximas, médias e mínimas. O OD apresentou relação inversa com a temperatura atmosférica nas duas sub-bacias. O pH do ponto 2 apresentou correlações negativas com a temperatura atmosférica, assim como a turbidez do ponto 1 (-0,67 temp. mín. dois dias). A cor apresentou correlações negativas com a temperatura atmosférica nas duas sub-bacias. A CE (0,74 temp. mín. dois dias) e os CF (0,74 temp. mín. dois dias) apresentaram correlação positiva com a temperatura atmosférica para o ponto 2. De maneira geral, constatou-se que a qualidade da água da sub-bacia 2 é fortemente influenciada pela agricultura, juntamente com a falta de vegetação ciliar e a adubação com dejeto animal. A sub-bacia 1 apresentou melhor qualidade da água devido a maior porcentagem de vegetação nativa. Entretanto, a falta de Área de Preservação Permanente nas nascentes e as granjas localizadas a montante da bacia afetam a qualidade da água.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-08-22T19:19:04Z No. of bitstreams: 1 EduardoLopes.pdf: 12990864 bytes, checksum: 2b2a568d3fb9037ed627e166e6ff577f (MD5) / Made available in DSpace on 2017-08-22T19:19:04Z (GMT). No. of bitstreams: 1 EduardoLopes.pdf: 12990864 bytes, checksum: 2b2a568d3fb9037ed627e166e6ff577f (MD5) Previous issue date: 2007-12-07 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / This study aims to perform a physical characterization and to evaluate the environmental impacts provoked by the Ribeira landfill in the Sabino’s bayou, which is part of the basin of Tibiri, in São Luís, state of Maranhão. Physical-chemical and morphometrical analyses have been made, and also bibliographical and cartographical surveys on the sub-basin of Sabino (Sabino’s bayou). As field parameter, pH, water temperature, conductivity, flow velocity of channel, sinuosity, shape of transversal section, area of transversal section and river discharge have been measured. By means of laboratory analyses, oxygen dissolved in water, oxygen biochemical demand and tenors of heavy metals (Pb, Hg, Zn, Cu, Cd, Ni and Fe) have been determined. The results obtained to the circularity index, factor of form and coefficient of compactness show that the sub-basin has an enlongated form being little susceptible to floodings. The concentration of dissolved oxygen is below the level permitted by CONAMA legislation (up to 5 mg/l) in almost all sampled areas. In the first sampled area, it has been detected a high DB05 in several months of the year and the tenors of Hg, Pb, Zn, Cu, and Fe are above the levels permitted by CONAMA legislation, which shows various impacts in the area studied. / Este trabalho teve por objetivo realizar uma caracterização física e avaliar os impactos ambientais provocados pelo Aterro da Ribeira no Igarapé do Sabino, que faz parte da Bacia do Tibiri, em São Luís, Ma. Foram realizadas análises físico-químicas, morfométricas e feitos levantamentos bibliográficos e cartográficos sobre a sub-bacia do Sabino (Igarapé do Sabino). Como parâmetros de campo, foram medidos: pH, temperatura da água, condutividade, velocidade do fluxo do canal fluvial, sinuosidade, forma da seção transversal, área da seção transversal e descarga do rio. Foram determinados, por análises laboratoriais, oxigênio dissolvido na água, demanda bioquímica de oxigênio e teores de metais pesados (Pb, Hg, Zn, Cu, Cd, Ni e Fe). Os resultados obtidos para o índice de circularidade, o fator de forma e o coeficiente de compacidade apontam que a Sub-bacia possui uma forma alongada sendo pouco suscetível a enchentes. A concentração do oxigênio dissolvido está abaixo do permitido pela legislação do CONAMA (até 5 mg/L) em quase todos os pontos amostrados. No primeiro ponto de amostragem foi detectado uma alta DBO5 em vários meses do ano e os teores de Hg, Pb, Zn, Cu e Fe estão acima dos permitidos pela resolução do CONAMA, indicando vários impactos na área estudada.

Fluctuations in temperature and precipitation amounts due to climate change influence recharge rate of groundwater. Any variations in the amount of precipitation recharge and artificial discharge directly affect groundwater level and so the salt water intrusion rate in the aquifers, which are in contact with sea water. The purpose of this study is to determine the overall historical precipitation recharge trend in Sel&ccedil / uk sub-basin and to detect whether there is a decrease or increase in recharge amounts due to climate change since 1100 BC. Besides, it covers assessing the future position of the salt water-fresh groundwater interface as a result of possible fluctuations in climate and artificial discharge. For this purpose, numerical density dependent cross sectional groundwater flow with solute transport model was conducted using finite element approach. At first, current salt water-fresh water interface and artificial discharge related head changes in the aquifer were determined. Backward modeling was utilized to obtain concentration distribution in the year 1976 representing the last stage of the undisturbed period. Then, progradation of salt water-fresh water interface since 1100 BC to 1976 was modeled using calibrated parameters and current recharge value. As a result of sea-regression model simulations (1100 BC-1976) less degree of salt water intrusion than that of currently detected in the area was obtained. The result suggests that overall recharge amount in the last 3076 years must have been less than that of 1976. Moreover, future (2010-2099) position of the interface and head changes under the influence of both climate change and increasing water demand were determined. Future model simulations indicate that salt water-fresh water interface moves farther landward. However this movement is mostly due to increasing discharge amount rather than that of climatic changes.

O presente estudo foi realizado na sub-bacia do arroio Estância Velha, pertencente à bacia hidrográfica do Rio dos Sinos, no município de Estância Velha, situado na Região Metropolitana de Porto Alegre, capital do Estado do Rio Grande do Sul. Objetivou-se diagnosticar a qualidade das águas da sub-bacia do arroio Estância Velha através da caracterização dos aspectos socioambientais, da percepção da comunidade, da análise pelos parâmetros indicados da Resolução nº 357/05 do Conama e do Índice de Qualidade de Águas (IQA), tendo como produto final uma cartografia temática. Com base nos trabalhos de campo, nas imagens de satélite, nos referenciais teóricos e no resultado das análises laboratoriais, identificaram-se as possíveis fontes de poluição da referida sub-bacia hidrográfica, sendo elas pontuais (lançamentos de esgotos e de efluentes industriais) e difusas (escoamento superficial), o que apresenta a possível relação entre a fonte e o produto gerado. As atividades industriais do setor coureiro-calçadistas, as indústrias químicas e os curtumes são a possível fonte de cromo. Incorporam-se ao trabalho determinadas alternativas e estratégias que possam subsidiar o Poder Público e os agentes sociais na elaboração de planos e projetos que venham a redefinir e equilibrar a ocupação do espaço no município, com vistas à integração e à complementaridade entre atividades urbanas e rurais, no intuito de contribuir para a gestão ambiental municipal. / The present study it was carried through in the sub -basin of the little stream Estância Velha, pertaining to the hydrographic basin of the Rio dos Sinos, in Estância Velha City,situated in the Metropolitan Region of Porto Alegre, Capital of the State of the RioGrande do Sul. It was objectified to diagnosis the quality of waters of the sub-basin of the little stream Estância Velha through the characterization of the ambient aspects partner, the perception of the community, the analysis for the parameters indicated in the Resolution Number 357/05 of the Conama and of the Index of Quality of Waters (IQA), having as end item a thematic cartography. On the basis of the field works, in the images of satellite, the theoretical references and the result of the analyses of the laboratories, had identified the possible sources of pollution of the related hydrographic sub-basin, they being prompt (launchings of sewers and effluent industriais) and diffuse (superficial draining), what it presents the possible relation between the source and the generated product. The industrial activities of the sector of leather footwear, the chemical industries and the tanneries are the possible chromium source. To the work is added some alternatives and strategies that can subsidize the Public Power and the Social Agents in the elaboration of plans and projects that come to redefine and to balance the occupation of the space in the city, with sights to the integration and the complementation between urban and agriçultural activities, in intention to contribute for the municipal ambient management.

This dissertation examines some of the strengths and weaknesses in basin level governance particularly as it relates to three current policy priorities: adaptive governance, international frameworks for response to natural and man-made disasters, and resilience in integrated water resources management. While these priorities are well-established in the academic and policy literature, in practice the ability to implement them at multiple levels has proven challenging. Though my dissertation highlights these challenges using case studies of European river basins, the observations and lessons for improving integrated management at multiple levels of governance, in multiple sectors, and among various actors are more broadly relevant to other natural resource governance settings. The first paper of this dissertation explores adaptive governance in the Tisza sub-basin, considering both constraints and policy options for strengthening adaptive governance at the sub-basin level. The Tisza is the largest sub-basin to the Danube River basin, and faces increasing pressures exacerbated by climate change. The Tisza countries have experienced challenges with managing climate change adaptation in a nested, consistent, and effective manner pursuant to the European Union Water Framework Directive. This is due, in part, to inefficiencies in climate change adaptation, such as weakened vertical coordination. This paper examines the conceptual domains relating to adaptation in international governance, and adaptation in transboundary water management in particular, with a focus on multilevel governance. International laws and policies governing transboundary waters in the Danube basin and Tisza sub-basin are reviewed. Using interviews and document analysis, the paper highlights challenges to adaptation in the Tisza sub-basin, including policy, fiscal, institutional, and capacity. The paper concludes with an exploration of possible policy options for sub-basin management, such as the development of a sub-basin commission, the establishment of a permanent Tisza expert group to be housed at and coordinated by the ICPDR, the use of new or existing bilateral treaties, and designing a framework for managing the Tisza. The second paper analyzes the transition in international frameworks of response to natural and man-made disasters as incorporated and integrated at multiple levels of governance. It begins with a discussion of the distinctions between so-called “natural” disasters and “man-made” accidents, how and why they are treated differently, and how recent developments in international law and practice are raising questions about the merits of these historic distinctions. Anthropogenic climate change drives more extreme and sometimes cascading disasters that require complex and overlapping types of response; it is argued that the distinctions in response to natural and man-made disasters are counterproductive, outdated, and ultimately flawed. The paper examines the policy and institutional frameworks governing response to natural disasters and man-made accidents in the Danube River basin and Tisza River sub-basin. Using expert interviews and legal and policy analysis, it then explores the differences in how natural disasters and man-made accidents are monitored and how they are responded to. The paper concludes with an analysis of the implications of transitioning policies toward a more holistic framework for response, regardless of whether the cause is natural, man-made, or (as is increasingly the case) some combination. The third paper advances the concept of a new approach – resilient IWRM – and how this approach can be applied to the management practices of the Danube and Rhine River basins and other river basins around the world. Using the Sendai Framework for Disaster Risk Reduction, the leading framework for resilience, and supported by expert interviews, the paper analyzes what resilience measures have been addressed, and what gaps remain in the basin management frameworks of the Danube and Rhine River basins. The paper concludes with a discussion of the current constraints in the resilient IWRM framework of the Danube and Rhine River basins, in addition to options for overcoming these challenges. This dissertation concludes with a discussion of crosscutting dimensions of analysis, specifically the challenges faced in integrating climate change adaptation, response to natural and man-made disasters, and resilience into multiple levels of water governance. While these conceptual elements are well-established, the ability to operationalize these elements has proven difficult from multiple perspectives highlighted in this dissertation. The difficulties suggest a more nuanced and pragmatic approach to both their framing and their operationalization.

O presente estudo foi realizado na sub-bacia do arroio Estância Velha, pertencente à bacia hidrográfica do Rio dos Sinos, no município de Estância Velha, situado na Região Metropolitana de Porto Alegre, capital do Estado do Rio Grande do Sul. Objetivou-se diagnosticar a qualidade das águas da sub-bacia do arroio Estância Velha através da caracterização dos aspectos socioambientais, da percepção da comunidade, da análise pelos parâmetros indicados da Resolução nº 357/05 do Conama e do Índice de Qualidade de Águas (IQA), tendo como produto final uma cartografia temática. Com base nos trabalhos de campo, nas imagens de satélite, nos referenciais teóricos e no resultado das análises laboratoriais, identificaram-se as possíveis fontes de poluição da referida sub-bacia hidrográfica, sendo elas pontuais (lançamentos de esgotos e de efluentes industriais) e difusas (escoamento superficial), o que apresenta a possível relação entre a fonte e o produto gerado. As atividades industriais do setor coureiro-calçadistas, as indústrias químicas e os curtumes são a possível fonte de cromo. Incorporam-se ao trabalho determinadas alternativas e estratégias que possam subsidiar o Poder Público e os agentes sociais na elaboração de planos e projetos que venham a redefinir e equilibrar a ocupação do espaço no município, com vistas à integração e à complementaridade entre atividades urbanas e rurais, no intuito de contribuir para a gestão ambiental municipal. / The present study it was carried through in the sub -basin of the little stream Estância Velha, pertaining to the hydrographic basin of the Rio dos Sinos, in Estância Velha City,situated in the Metropolitan Region of Porto Alegre, Capital of the State of the RioGrande do Sul. It was objectified to diagnosis the quality of waters of the sub-basin of the little stream Estância Velha through the characterization of the ambient aspects partner, the perception of the community, the analysis for the parameters indicated in the Resolution Number 357/05 of the Conama and of the Index of Quality of Waters (IQA), having as end item a thematic cartography. On the basis of the field works, in the images of satellite, the theoretical references and the result of the analyses of the laboratories, had identified the possible sources of pollution of the related hydrographic sub-basin, they being prompt (launchings of sewers and effluent industriais) and diffuse (superficial draining), what it presents the possible relation between the source and the generated product. The industrial activities of the sector of leather footwear, the chemical industries and the tanneries are the possible chromium source. To the work is added some alternatives and strategies that can subsidize the Public Power and the Social Agents in the elaboration of plans and projects that come to redefine and to balance the occupation of the space in the city, with sights to the integration and the complementation between urban and agriçultural activities, in intention to contribute for the municipal ambient management.

O presente estudo foi realizado na sub-bacia do arroio Estância Velha, pertencente à bacia hidrográfica do Rio dos Sinos, no município de Estância Velha, situado na Região Metropolitana de Porto Alegre, capital do Estado do Rio Grande do Sul. Objetivou-se diagnosticar a qualidade das águas da sub-bacia do arroio Estância Velha através da caracterização dos aspectos socioambientais, da percepção da comunidade, da análise pelos parâmetros indicados da Resolução nº 357/05 do Conama e do Índice de Qualidade de Águas (IQA), tendo como produto final uma cartografia temática. Com base nos trabalhos de campo, nas imagens de satélite, nos referenciais teóricos e no resultado das análises laboratoriais, identificaram-se as possíveis fontes de poluição da referida sub-bacia hidrográfica, sendo elas pontuais (lançamentos de esgotos e de efluentes industriais) e difusas (escoamento superficial), o que apresenta a possível relação entre a fonte e o produto gerado. As atividades industriais do setor coureiro-calçadistas, as indústrias químicas e os curtumes são a possível fonte de cromo. Incorporam-se ao trabalho determinadas alternativas e estratégias que possam subsidiar o Poder Público e os agentes sociais na elaboração de planos e projetos que venham a redefinir e equilibrar a ocupação do espaço no município, com vistas à integração e à complementaridade entre atividades urbanas e rurais, no intuito de contribuir para a gestão ambiental municipal. / The present study it was carried through in the sub -basin of the little stream Estância Velha, pertaining to the hydrographic basin of the Rio dos Sinos, in Estância Velha City,situated in the Metropolitan Region of Porto Alegre, Capital of the State of the RioGrande do Sul. It was objectified to diagnosis the quality of waters of the sub-basin of the little stream Estância Velha through the characterization of the ambient aspects partner, the perception of the community, the analysis for the parameters indicated in the Resolution Number 357/05 of the Conama and of the Index of Quality of Waters (IQA), having as end item a thematic cartography. On the basis of the field works, in the images of satellite, the theoretical references and the result of the analyses of the laboratories, had identified the possible sources of pollution of the related hydrographic sub-basin, they being prompt (launchings of sewers and effluent industriais) and diffuse (superficial draining), what it presents the possible relation between the source and the generated product. The industrial activities of the sector of leather footwear, the chemical industries and the tanneries are the possible chromium source. To the work is added some alternatives and strategies that can subsidize the Public Power and the Social Agents in the elaboration of plans and projects that come to redefine and to balance the occupation of the space in the city, with sights to the integration and the complementation between urban and agriçultural activities, in intention to contribute for the municipal ambient management.

Le bassin amazonien est considéré au niveau mondial comme l'un des principaux apports de sédiments à l'Océan Atlantique. Comprendre la distribution spatiale et temporelle des flux sédimentaires est l'objectif de cette étude pour laquelle on a choisi quatre stations hydrométriques de suivi réparties tout au long de l'Amazone depuis sa formation au Pérou jusqu'à environ 800 km de son embouchure au Brésil (Óbidos). Pour atteindre cet objectif, on a mis en place pour chaque station un échantillonnage décadaire en surface et une exploration totale de leur section à différentes périodes de l'année. Des profils de turbidité et des échantillons pour la granulométrie sur toute la section faisaient également partie de ce suivi. Sur les stations andines et sub-andines, la turbulence de l'écoulement jointe aux faibles profondeurs permet l'ascension de sédiments grossiers vers la surface. Par conséquent, on observe une relation directe entre la concentration de sédiments en suspension de surface et la concentration moyenne dans la section, ce qui permet un calcul simple des flux sédimentaires et d'arriver à une valeur de 540 Mt/an pour qui concerne l'apport du basin péruvien de l'Amazone. Dans la plaine brésilienne, le contexte change, les profondeurs moyennes se situent entre 40 et 100 m de telle sorte que la présence de sable en surface est quasi nulle. Cependant, l'analyse des résultats à la station d'Óbidos montre qu'il existe une relation directe entre la concentration de sédiments de surface et la concentration moyenne de sédiments fins dans la section alors que la concentration moyenne de sédiments grossiers dans la section est, elle, em relation directe avec le débit liquide. En différenciant ainsi le calcul suivant ces deux types de sédiments, on arrive à une valeur de flux de 1100 Mt/an transitant par Óbidos, dont 60% correspond au flux des sédiments fins et 40% aux grossiers. On a utilisé la turbidité pour par courbes de calibration em funtion da granulometrie parvenir aux valeurs de concentration. On a utilisé le modèle de Rouse pour différencier le signal de concentration obtenu avec la turbidité résultat du signal de le deux types de sediment. On a constaté que les granulométries en présence sont les mêmes tout au long du régime hydrologique mais que ce sont les proportions de chacune d'entre elles qui varient. Aussi a-t-on abouti à des profils de concentration pour sédiments fins et des profils pour sédiments grossiers. En montée de crue, les profils de concentration présentent un gradient bien marqué pour les sédiments fins, alors qu'en période de crue ce gradient est contrôlé par les sables et les profils de fines sont alors verticaux et constants sur toute la section. Ces résultats montrent qu'il est possible de prédire, en Amazonie, les profils de concentration à partir de la turbidité. / The sediments flux in Amazon Basin have an important role on the aquatic biodiversity and richness in the floodplains because the nutrients and organic matter attached on suspended sediments are deposited in these zones. The aim of this study is to understand the spatial and temporal distribution of sediments flux in the Amazon River, therefore were select four gauging station located along of Amazon Riven from Peru to Brazil. In each gauging station was make superficial samples each ten days and samples in the section in different times of hydrological period. Turbidity profiles and granulometry measuring were made too in each gauging station. In the Andean region, it is observed a relationship between the suspended sediments concentration and discharge, however, this relationship become a hysteresis in the plain especially in the Óbidos gauging station located at 870 km before of mouth. This result can be by the contribution of influx poor in suspended sediments from Guyanese and Brazilian shields. In 3000 km of long from Peru to Brazil plain, the suspended sediments is composed by two well-defined types of suspended sediments: fine sediments (10-20 µm) and coarse sediments (100-250 µm). The percentage of each type of sediments in the main river is different during the hydrologic regime. Peak of fine sediments is observed in the same period of peak of rainfall (December to March) and peak of coarse sediments is observed in flood period (May to July). The Andean and sub-Andean basin gauging station show the coarse sediments in surface due to great turbulence and low depths. Therefore, this gauging station show a relationship between the suspended sediments concentration in surface and average suspended sediments concentration in section, with this relation is possible to calculate the suspended sediments flux. Hence the Peruvian basin provide 540 Mt year -1. However in the Brazilian plain the context is different, the depth is from 40 to 100 m, becoming almost null the presence of coarse sediments in the surface. Therefore, cannot use the relationship between suspended sediments concentration in surface and average suspended sediments concentration in section. When the Óbidos gauging station is analysed, it found there is a relationship between suspended sediments concentration in surface and average of fine suspended sediments concentration. It is observed too, that there is the relationship between coarse suspended sediments concentration and discharge. Therefore, it is possible to calculate of suspended sediments flux using these two relationships. The Amazon River export 1100 Mt year-1 of suspended sediments at Óbidos gauging station, of which 60% correspond at fine sediments flux and 40% to coarse sediments flux. It is observed that the suspended sediments are sensitivity of climate variability, generally El Niño events is associate with increase of fine suspended sediments and La Niña events increase a percentage of coarse sediments in Amazon River. It is using the turbidity for determinate of suspended sediments concentration, we use this technique due the high frequency in acquisition of data. However for use the turbidity is necessary the previous calibration. It was observed that the turbidity signal is an addition to the signal emitted by the particles in one sample and with this assumption the Rose model was used to separate the concentration signal obtained by the turbidity of the two types of sediments present in the Amazon River, fine particles and sand. Therefore, it was obtained the concentration profiles to fine sediments and the concentration profiles to the sand. It is observed during the rising period that the fine sediments profiles show a strong gradient, however in the flood periods this gradient reduce come a constant in all section. These results show that turbidity and Rouse model can be used for prediction of suspended concentration in Amazon River.

Made available in DSpace on 2016-08-10T10:55:50Z (GMT). No. of bitstreams: 1 MARCIO CANDIDO DA COSTA.pdf: 5607830 bytes, checksum: c8c43148342a24b1c2c806f36f7baf80 (MD5) Previous issue date: 2006-07-07 / In order to characterize the fish fauna of the Claro river sub-basin as well as to establish a distributional pattern based on the hypothesis of the ichtyofaunistic differentiation promoted by the segmentation of the river by possible natural barriers, six stretches along this river and the confluence of its main tributaries were sampled in December 2005 (rainy season). The collecting sites were chosen on the basis of the presence of waterfalls or rapids along the river. There were 372 specimens collected distributed in 4 orders, 15 families, 5 subfamilies, 32 genera, and 48 species. The animals were collected with the use of nets with mashes varying from 12 and 90 mm between knots, coop with funneled entrances and throw nets. The primary data were correlated with available data of the same nature from other localities within the Paranaíba river basin, upper Paraná hydrographic region. The indexes of constancy, dominance, abundance, richness, similarity, and diversity of species were considered, besides the curve of rarefaction of species analysis and detrended correspondence analysis (DCA). Generally the data supports a differentiation among stretches, which suggests a correlation with the rapids that establish a negative gradient of species upstream of Claro river. The higher indexes were attributed to Point 2, where there are tributaries of several categories therefore the importance of the management and preservation of these environments. / No intuito de caracterizar a ictiofauna presente na sub-bacia do rio Claro, bem como estabelecer um padrão de distribuição, baseado na hipótese da existência de diferenciação ictiofaunística promovida pela segmentação do curso do rio, em função de possíveis barreiras naturais, foram amostrados seis trechos distribuídos ao longo desse rio e nos pontos de confluência com alguns de seus principais afluentes, em dezembro de 2005 (estação chuvosa). Os trechos foram demarcados com base na presença de cachoeiras ou quedas d água, no sentido jusante-montante do rio. Foram coletados 372 espécimes, distribuídos em 4 ordens, 15 famílias, 5 subfamílias, 32 gêneros e 48 espécies. Os animais foram coletados com o uso de redes de espera, com malhas variando entre 12 e 90 mm entre nós, gaiolas tipo covo e tarrafas. Os dados primários foram correlacionados com os dados disponíveis, da mesma natureza, para outras localidades contidas na bacia do rio Paranaíba, região hidrográfica do alto Paraná. Foram considerados os índices de constância, dominância, abundância, riqueza, similaridade e diversidade de espécies, além de análise da curva de rarefação de espécies e análise de correspondência (DCA). De maneira geral, os dados apontam para uma diferenciação entre os trechos, correlacionada com a presença das quedas d água, as quais estabelecem um gradiente negativo de espécies no sentido jusantemontante do rio Claro. Os maiores índices foram atribuídos ao Trecho 2, onde existe a presença de tributários de diversas categorias, daí a importância da manutenção e preservação desses ambientes.