O objetivo do presente estudo é caracterizar a hidrodinâmica e o transporte de material particulado em suspensão (MPS) no estuário de Caravelas sob diferentes condições de maré e vazão fluvial. Foram realizadas quatro campanhas hidrográficas durante ciclos completos de maré, sendo em condições de maré de sizígia e quadratura, e durante os períodos seco e chuvoso. Dados de nível de água, velocidade e direção de correntes, salinidade, temperatura e turbidez foram obtidos em uma estação fixa próxima da desembocadura do estuário. A partir destes dados foram obtidos os transportes residuais de MPS e calculado os mecanismos de transporte. As maiores concentrações médias de material particulado em suspensão ocorreram em condições de sizígia. Em condições de maré de quadratura o transporte resultante de MPS foi com sentido estuário acima, porém de pequena intensidade. Em condições de sizígia o estuário é caracterizado por correntes mais intensas e assimétricas, com dominância de vazante. Durante a condição de sizígia o estuário pode atuar como importador ou exportador de MPS. O estuário do rio Caravelas foi classificado como bem misturado e fracamente estratificado. A hidrografia e o balanço sedimentar são principalmente modulados pela altura da maré e o aporte de água doce é irrelevante. / The objective of the present study is to characterize the hydrodynamics and the suspended particulate matter (SPM) in the Caravelas Estuary under different tidal and river regimes. Four hydrographic campaigns were carried out comprising a complete semi-diurnal tidal cycle, comprising neap and spring tidal phases, and during dry and wet seasons. Water level, current speed and direction, salinity, temperature and turbidity were recorded in an anchored station near to the estuarine mouth. The residual SPM flux and the mechanisms of transport were calculated. The higher SPM concentrations were recorded during the spring tidal phase. During neap tides, the net SPM flux 1 was up-estuary, although with low scale. During spring tides the tidal currents are strongly ebb dominant, and the net flux can be either up- or down-estuary. The estuary was classified as well mixed or weakly stratified. The hydrography and the sediment balance are firstly modulated by the tidal range, and the fresh water inflow is negligible.

O objetivo do presente estudo é caracterizar a hidrodinâmica e o transporte de material particulado em suspensão (MPS) no estuário de Caravelas sob diferentes condições de maré e vazão fluvial. Foram realizadas quatro campanhas hidrográficas durante ciclos completos de maré, sendo em condições de maré de sizígia e quadratura, e durante os períodos seco e chuvoso. Dados de nível de água, velocidade e direção de correntes, salinidade, temperatura e turbidez foram obtidos em uma estação fixa próxima da desembocadura do estuário. A partir destes dados foram obtidos os transportes residuais de MPS e calculado os mecanismos de transporte. As maiores concentrações médias de material particulado em suspensão ocorreram em condições de sizígia. Em condições de maré de quadratura o transporte resultante de MPS foi com sentido estuário acima, porém de pequena intensidade. Em condições de sizígia o estuário é caracterizado por correntes mais intensas e assimétricas, com dominância de vazante. Durante a condição de sizígia o estuário pode atuar como importador ou exportador de MPS. O estuário do rio Caravelas foi classificado como bem misturado e fracamente estratificado. A hidrografia e o balanço sedimentar são principalmente modulados pela altura da maré e o aporte de água doce é irrelevante. / The objective of the present study is to characterize the hydrodynamics and the suspended particulate matter (SPM) in the Caravelas Estuary under different tidal and river regimes. Four hydrographic campaigns were carried out comprising a complete semi-diurnal tidal cycle, comprising neap and spring tidal phases, and during dry and wet seasons. Water level, current speed and direction, salinity, temperature and turbidity were recorded in an anchored station near to the estuarine mouth. The residual SPM flux and the mechanisms of transport were calculated. The higher SPM concentrations were recorded during the spring tidal phase. During neap tides, the net SPM flux 1 was up-estuary, although with low scale. During spring tides the tidal currents are strongly ebb dominant, and the net flux can be either up- or down-estuary. The estuary was classified as well mixed or weakly stratified. The hydrography and the sediment balance are firstly modulated by the tidal range, and the fresh water inflow is negligible.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-07-03T13:40:43Z No. of bitstreams: 2 Tese - Isabel Rodrigues da Rocha - 2018.pdf: 13506861 bytes, checksum: 62a627a5358951b6c7a08e05e36e6b7e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-07-03T15:50:29Z (GMT) No. of bitstreams: 2 Tese - Isabel Rodrigues da Rocha - 2018.pdf: 13506861 bytes, checksum: 62a627a5358951b6c7a08e05e36e6b7e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-07-03T15:50:29Z (GMT). No. of bitstreams: 2 Tese - Isabel Rodrigues da Rocha - 2018.pdf: 13506861 bytes, checksum: 62a627a5358951b6c7a08e05e36e6b7e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-05-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The development of mankind has always been connected to water resources. Currently, they have been more intensely exploited, especially in electrical power generation, through the opening of countless hydropower plants in Brazil from which many are found in the biome called Cerrado, due to its great water resources. From the need of studies on artificial reservoir once its made, the study on Salto do Rio Verdinho ́s river basin and waterpower plant ́s reservoir, located in the lower part of Verde river ́s river basin, close to Paranaíba river ́s downstream, tributary of Paraná river, was chosen. Verde river ́s flow is the verge of Caçu and Itarumã counties, in the south of Goiás state. Therefore, the main goal of this work is to comprehend the dynamics of usage and occupation of the river basin ́s lands and Salto do Rio Verdinho ́s waterpower plant relating to its water quality. With that in mind, the landscape was rated according to its physical features and the relation among its geology, soils, slope, geomorphology and remaining natural vegetation, based on the observation of the structural principle of the landscape, revealing that the environment of the river basin region belongs to Mesozoic era ́s geological formations, such as flattened relief and predominance of slope with very soft dissection between interfluves. Data on the changes in usage and occupation of the lands was possible through satellites images, where it was found that between 2005 and 2015, the main usage was pasture with 546 km2, the second, was areas intended to temporary cultures, with 237,4 km2. The analyses regarding the quality of the water from the reservoir, were made according to the resolution no 357 from 2005 of CONAMA, it was ranked as of very low quality due to its high percentage of nitrite and phosphorus. It was ranked as class 4. The variables: TDS and CE, Temp and TDS, Temp and CE, present significant correlations. The components optically active in the water (chlorophyll, concentration of suspended sediment, transparency and murkiness) that interfere in the electromagnetic spectra, present correlations with the measures of reflectance in the wavelength of 716 nm and 720 nm in January 2015, while the variables correlated better with the wavelength of 647 nm, 697 nm e 704 nm in February 2016, pointing that these wavelengths belong to the color red. The reflectance during the rainy months, January 2015 and February 2016, registered values between 0,04 and 0,23%, while in the dry season, July 2015 and August 2016, 0,03 and 0,14%. Generally speaking, that the research led to comprehend the current dynamics of the river basin environment and of the hydropower plant Salto do Rio Verdinho ́s reservoir, on their natural and man induced components that affect the water quality, thus, fulfilling the intended general aim. / O desenvolvimento da humanidade, sempre esteve ligado aos usos dos recursos hídricos. E na atualidade esses recursos, vem sendo explorado com mais intensidade, especialmente para a geração de energia elétrica, a partir da implantação de inúmeras hidrelétricas no Brasil e sobretudo muitas no Bioma Cerrado, que detém grande riqueza de recursos hídricos. Na perspectiva, de estudos necessários em ambiente de reservatório artificial após a sua implantação, o objeto do estudo selecionado foi a bacia hidrográfica e o reservatório da usina hidrelétrica (UHE) Salto do Rio Verdinho, localizada no trecho inferior da bacia hidrográfica do Rio Verde, próximo a jusante no Rio Paranaíba, afluente do Rio Paraná. Assim, o curso fluvial do Rio Verde é o limite territorial dos municípios de Caçu e Itarumã, no sul do estado de Goiás. Portanto, o presente trabalho teve por objetivo geral, compreender a dinâmica de uso e ocupação das terras da bacia e do reservatório da UHE Salto do Rio Verdinho em relação a qualidade das suas águas. Diante disso, foram realizadas avaliações da paisagem a partir da caracterização física e da relação dos seus atributos de geologia, solos, declividade, geomorfologia e remanescentes de vegetação natural, baseado na observação de princípio estrutural da paisagem, revelando que o ambiente da região da bacia como todo pertence a formações geológicas da Era Mesozoica, com relevos aplainados, e predomínio de declividades com dissecação muito fraca entre os interflúvios. As alterações no Uso e Ocupação das Terras, foram realizadas a partir de interpretação de imagens de satélites, onde se verificou que entre 2005 a 2015, o uso predominante são destinadas às áreas de pastagens com 546 km2, e a segunda classe de maior uso, foram de áreas destinadas para culturas temporárias com 237,4 km2. A análise da qualidade das águas do reservatório, foram realizadas segundo a Resolução no 357 de 2005 do CONAMA, sendo classificada como de péssima qualidade, devido aos elevados valores do nitrito e do fósforo nas águas do reservatório, que permitiram enquadra- las na classe 4. As variáveis TDS e CE, Temp e TDS, Temp e CE apresentaram correlações significativas. Os Componentes Oticamente Ativos (Clorofila, Concentração de Sedimentos em Suspensão, Transparência da água e Turbidez) na água que interferem nos espectros eletromagnéticos, apresentaram correlações com às medidas das reflectâncias nas faixas de 716 nm e 720 nm no mês de janeiro de 2015, enquanto que em fevereiro de 2016 as variáveis se correlacionaram melhores com as faixas de 647 nm, 697 nm e 704 nm, indicando que essas faixas compreendem ao comprimento de onda de luz vermelha. As reflectâncias dos meses chuvosos, de janeiro de 2015 e fevereiro de 2016, registraram valores entre 0,04 e 0,23%, já nos períodos secos registraram valores entre 0,03 e 0,14%, para os meses de julho de 2015 e agosto de 2016. De modo geral, a pesquisa, permitiu compreender a dinâmica atual do ambiente da bacia e do reservatório da UHE Salto do Rio Verdinho, sobre suas componentes naturais e antrópicas que afetam a qualidade das águas, assim, atingindo o objetivo geral proposto.

O objetivo do presente estudo é caracterizar a hidrodinâmica e o transporte de material particulado em suspensão (MPS) no estuário de Caravelas sob diferentes condições de maré e vazão fluvial. Foram realizadas quatro campanhas hidrográficas durante ciclos completos de maré, sendo em condições de maré de sizígia e quadratura, e durante os períodos seco e chuvoso. Dados de nível de água, velocidade e direção de correntes, salinidade, temperatura e turbidez foram obtidos em uma estação fixa próxima da desembocadura do estuário. A partir destes dados foram obtidos os transportes residuais de MPS e calculado os mecanismos de transporte. As maiores concentrações médias de material particulado em suspensão ocorreram em condições de sizígia. Em condições de maré de quadratura o transporte resultante de MPS foi com sentido estuário acima, porém de pequena intensidade. Em condições de sizígia o estuário é caracterizado por correntes mais intensas e assimétricas, com dominância de vazante. Durante a condição de sizígia o estuário pode atuar como importador ou exportador de MPS. O estuário do rio Caravelas foi classificado como bem misturado e fracamente estratificado. A hidrografia e o balanço sedimentar são principalmente modulados pela altura da maré e o aporte de água doce é irrelevante. / The objective of the present study is to characterize the hydrodynamics and the suspended particulate matter (SPM) in the Caravelas Estuary under different tidal and river regimes. Four hydrographic campaigns were carried out comprising a complete semi-diurnal tidal cycle, comprising neap and spring tidal phases, and during dry and wet seasons. Water level, current speed and direction, salinity, temperature and turbidity were recorded in an anchored station near to the estuarine mouth. The residual SPM flux and the mechanisms of transport were calculated. The higher SPM concentrations were recorded during the spring tidal phase. During neap tides, the net SPM flux 1 was up-estuary, although with low scale. During spring tides the tidal currents are strongly ebb dominant, and the net flux can be either up- or down-estuary. The estuary was classified as well mixed or weakly stratified. The hydrography and the sediment balance are firstly modulated by the tidal range, and the fresh water inflow is negligible.

The purpose of this study is to gain some first insights into the role of burst-like turbulent motions in sediment suspension over a sandy channel bed, during typical conditions of strong sediment transport with active bedforms. The focus is the suspension mechanism that maintains sizeable sediment concentrations away from the bed, where much of the downstream transport occurs, rather than entrainment at the sediment boundary itself. Flow components downstream and normal to the mean boundary, along with the output of an optical suspended sediment sensor, were monitored 1 m above the bed. The main study data were collected in a 10 m deep channel of the Fraser River near Mission, British Columbia, Canada. Velocities averaged 1.4 m/s at the surface and 0.9 m/s at the sensors, where mean suspended sediment concentrations were 500 mg/l; decimetre height small dunes on the backs of larger, metre amplitude dunes covered the channel bed. Many hours of data were recorded at 5 Hz, allowing multi-second scale turbulent motions as well as multi-minute oscillations to be resolved in both the velocity and turbidity records. Burst-like "ejection and inrush" motions were identified, producing a high degree of intermittency in momentum exchange: 80% of the mean Reynolds stress at the 1 m level is produced during 12% of the record duration. The burst recurrence period appears to be significantly greater than predicted by applying the conventional outer flow scaling in this environment. It is hypothesised that the non-uniform shear and pressure gradient conditions over the various scales of bedforms on the river floor may somehow affect mean burst periodicity, modifying the recurrence scaling developed over flat boundaries. The determination of a burst recurrence timescale from one-point data is inherently imprecise however and, as elsewhere, a continuous variation of return periods with relative magnitude of extreme (u'v') events is observed. The optical turbidity (OBS) time series reveals that these intermittent burst-like motions are, as expected, very important in vertically mixing sediments across the 1 m level in the flow; for example violent ejections, occurring only 1% of the time and contributing some 10% to mean turbulent momentum flux, appear to account for 6% of the total vertical sediment flux. The statistical association between the momentum and sediment mixing efficiencies of any ejection appears to be only moderately strong, however; very intense suspension can be associated with rather "weak" ejections (in terms of stress), and vice-versa. Differences between momentum and sediment mixing effects of a given ejection may partly be related to the "crossing trajectories effect"; sand grains continually fall out of the eddies that bear them, so the momentum and sediment "contents" of an eddy at 1 m off the bed are not perfectly linked. Turbulent sediment suspension is, like momentum exchange, a highly intermittent process in itself. After selecting turbulent events only for suspension efficiency, the largest ones, occupying only 5% of the time, contribute approximately one half of the total vertical sediment flux. There is no indication that the conventional scaling of burst recurrence corresponds to the occurrence of any distinctive event level for suspension. Interestingly, burst-like turbulent motions are not the only flow oscillations contributing to suspension in the high flow conditions of the study. Multi-minute period flow perturbations at 1 m off the bed significantly assist burst-scale turbulent motions in driving the upward sediment mixing. In summary, turbulent mixing of both momentum and sediment at 1 m over a typical sandy river bed is dominated by intermittent, intense "burst-like" events. However, the extrapolation of intermittent "bursting" concepts and structural constants from small-scale laboratory flows to the larger fluvial environment may be misleading. / Arts, Faculty of / Geography, Department of / Graduate

published_or_final_version / Civil Engineering / Master / Master of Philosophy

Sedimentos em suspensão representam um dos principais fatores que afetam a qualidade dos sistemas aquáticos no mundo; influenciam os processos geomórficos de construção da paisagem e podem indicar problemas de erosão e perda de solo na bacia hidrográfica contribuinte. O seu monitoramento espacial e temporal é fundamental nas atividades de gestão ambiental de áreas costeiras. Nesse sentido, a hipótese básica desta pesquisa é que o padrão espacial e temporal de plumas de sedimentos costeiras associado ao regime hidrológico do rio pode ser caracterizado a partir de imagens orbitais de média resolução espacial. Para comprová-la, elegeu-se a foz do rio Paraíba do Sul como área de estudo para definição e teste metodológico, e formulou-se como principal objetivo mapear qualitativamente a pluma costeira deste rio a partir de imagens Landsat 5 e CBERS-2, ao longo do período compreendido entre 1985 e 2007. As datas avaliadas foram criteriosamente definidas através de três estratégias de análise, totalizando cinqüenta imagens. Pesquisa bibliográfica e avaliação da resposta espectral da feição de interesse nas imagens selecionadas consistiram nas etapas principais da definição da metodologia. As plumas foram então identificadas, mapeadas e extraídas; posteriormente, suas características espaciais e temporais foram analisadas por intermédio de sistemas de informação geográfica e avaliadas em conjunto com dados históricos de vazão. Os resultados indicam que a banda do vermelho forneceu uma melhor discriminação interna da pluma, sendo, portanto, utilizada como base para as análises realizadas neste trabalho. Com exceção do procedimento de correção atmosférica, a metodologia proposta consiste na utilização de técnicas simples de processamento digital de imagens, baseadas na integração de técnicas semi-automáticas e de análise visual. A avaliação do padrão dos sedimentos e dos mapas temáticos qualitativos de concentração de sedimentos em suspensão indica a forte diferenciação existente entre cenários representativos de épocas de cheia e seca do rio. Análises espaciais do comportamento da pluma contribuem ainda para um maior conhecimento do espaço geográfico, fornecendo subsídios aos mais variados setores do planejamento e gestão ambiental. / Suspended sediments are a major factor affecting water quality in aquatic ecosystems of the world; they do influence the geomorphological processes of environmental formation and may indicate erosion problems and loss of ground on the contributing watershed. Its spatial and temporal monitoring is fundamental in the activities of the environmental management of the coastal areas. In that direction, the basic hypothesis of this research is that the spatial and temporal pattern of coastal plumes of sediments associated to the hydrological regime of the river may be characterized from orbital images of medium spatial resolution. To prove this, it was elected the mouth of Paraiba do Sul river as study area for defining and testing the methodology, which was formulated as principal purpose to map qualitatively the coastal plumes of this river from the images of Landsat 5 and CBERS-2, from the period between 1985 and 2007. The evaluated dates were defined with criteria through three strategies of analysis, totaling fifty images. Literature review and evaluation of the spectral response of the feature of interest consisted on the main steps of the definition of the methodology. The plumes were so identified, mapped and extracted; afterward, its spatial and temporal characteristics were analyzed by geographical information systems and evaluated together with historical data of river discharge. The results indicate that the red band yielded a better internal discrimination of the plume, being, therefore, used as basis to the analyses realized on this work. With exception of the procedure of atmospheric correction, the methodology proposal consists on the utilization of simple techniques of digital processing of images, based on the integration of semi-automatic and visual analyses techniques. The evaluation of the sediments pattern and qualitative thematic maps of suspended particulate matter indicates the strong differentiation existing between scenarios representing the periods of high and low waters of the river. Spatial analyses of the behavior of the plumes even contribute to a better knowledge of the geographical space, supplying subsidies to the most assorted sectors of environmental planning and management.

In coastal urban regions, underground stormwater treatment units are suitable infrastructure options because they take less space where premium land is expensive. Even then, they should be accessible and ideally small enough to fit into existing stormwater networks. Since 2003, the City of Tampa and Florida’s Department of Transportation (FDOT) have installed 47 baffle boxes into the city’s stormwater pipe networks. Baffle boxes are underground stormwater treatment structures designed to capture sediments and floating debris. Since their deployment, many challenges regarding their practical sediment capturing performance was raised by the city. The objective of this research was to evaluate the effects of rainfall, land use, and maintenance on the sediment trapping efficiency of the baffle boxes and identify solutions to enhance their performance. This was addressed through site visits, sediment accumulation measurements and analysis of historical and field data. The results of these measurements and analysis were then compared to rainfall intensity, catchment characteristics, size and type of the units. During the preliminary site visits and sediment measurements it was observed that most of the units located in the south of Tampa were inundated by backflows from Tampa Bay. Survey information collected from inspection crew members also showed that resuspension of trapped sediments frequently occurs in these units. Concerning operation and maintenance (O&M), it was indicated that units mounted with screens are costly and difficult to clean-out. Additionally, it was found that 80% of the units have very small trap inlets and lack the baffle structures needed to slow down and settle sediments. Historical sediment measurements and O&M practices were analyzed to calculate the overall performance of the units. The analysis of the data determined the sediments captured, the resuspension rate, and yearly cost of maintenance for different types of baffle boxes. Rainfall intensity and land use and land cover (LULC) data for each catchment of the units was correlated to the performance of the units. The LULC data used impervious fraction and tree canopy area of the catchments to project sediment and leaf matter accumulation within the units. This research study found that total daily rainfall intensity is a good predictor of sediment accumulation. Cleanout crews can use this relationship to conduct their work efficiently and to promptly react to occurring rainfall events. Thus, the prediction of sediments accumulated from rainfall events and the coordination of clean-out trucks can optimize O&M practices. It was also determined that large-sized (24-40 in) units and those with three chambers (baffles) perform better at trapping sediments. Thus, installing baffles in units within the large-sized ones can enhance their performance. The study also found that baffle boxes mounted with screens can individually take up to eight hours to cleanup which makes them costly and difficult. This can be detrimental for municipalities to follow up on their O&M practices effectively. Therefore, to alleviate the clean out complexity and reduce maintenance expenditures complementary practices such as bag filters need to be explored and implemented for trials

Sedimentos em suspensão representam um dos principais fatores que afetam a qualidade dos sistemas aquáticos no mundo; influenciam os processos geomórficos de construção da paisagem e podem indicar problemas de erosão e perda de solo na bacia hidrográfica contribuinte. O seu monitoramento espacial e temporal é fundamental nas atividades de gestão ambiental de áreas costeiras. Nesse sentido, a hipótese básica desta pesquisa é que o padrão espacial e temporal de plumas de sedimentos costeiras associado ao regime hidrológico do rio pode ser caracterizado a partir de imagens orbitais de média resolução espacial. Para comprová-la, elegeu-se a foz do rio Paraíba do Sul como área de estudo para definição e teste metodológico, e formulou-se como principal objetivo mapear qualitativamente a pluma costeira deste rio a partir de imagens Landsat 5 e CBERS-2, ao longo do período compreendido entre 1985 e 2007. As datas avaliadas foram criteriosamente definidas através de três estratégias de análise, totalizando cinqüenta imagens. Pesquisa bibliográfica e avaliação da resposta espectral da feição de interesse nas imagens selecionadas consistiram nas etapas principais da definição da metodologia. As plumas foram então identificadas, mapeadas e extraídas; posteriormente, suas características espaciais e temporais foram analisadas por intermédio de sistemas de informação geográfica e avaliadas em conjunto com dados históricos de vazão. Os resultados indicam que a banda do vermelho forneceu uma melhor discriminação interna da pluma, sendo, portanto, utilizada como base para as análises realizadas neste trabalho. Com exceção do procedimento de correção atmosférica, a metodologia proposta consiste na utilização de técnicas simples de processamento digital de imagens, baseadas na integração de técnicas semi-automáticas e de análise visual. A avaliação do padrão dos sedimentos e dos mapas temáticos qualitativos de concentração de sedimentos em suspensão indica a forte diferenciação existente entre cenários representativos de épocas de cheia e seca do rio. Análises espaciais do comportamento da pluma contribuem ainda para um maior conhecimento do espaço geográfico, fornecendo subsídios aos mais variados setores do planejamento e gestão ambiental. / Suspended sediments are a major factor affecting water quality in aquatic ecosystems of the world; they do influence the geomorphological processes of environmental formation and may indicate erosion problems and loss of ground on the contributing watershed. Its spatial and temporal monitoring is fundamental in the activities of the environmental management of the coastal areas. In that direction, the basic hypothesis of this research is that the spatial and temporal pattern of coastal plumes of sediments associated to the hydrological regime of the river may be characterized from orbital images of medium spatial resolution. To prove this, it was elected the mouth of Paraiba do Sul river as study area for defining and testing the methodology, which was formulated as principal purpose to map qualitatively the coastal plumes of this river from the images of Landsat 5 and CBERS-2, from the period between 1985 and 2007. The evaluated dates were defined with criteria through three strategies of analysis, totaling fifty images. Literature review and evaluation of the spectral response of the feature of interest consisted on the main steps of the definition of the methodology. The plumes were so identified, mapped and extracted; afterward, its spatial and temporal characteristics were analyzed by geographical information systems and evaluated together with historical data of river discharge. The results indicate that the red band yielded a better internal discrimination of the plume, being, therefore, used as basis to the analyses realized on this work. With exception of the procedure of atmospheric correction, the methodology proposal consists on the utilization of simple techniques of digital processing of images, based on the integration of semi-automatic and visual analyses techniques. The evaluation of the sediments pattern and qualitative thematic maps of suspended particulate matter indicates the strong differentiation existing between scenarios representing the periods of high and low waters of the river. Spatial analyses of the behavior of the plumes even contribute to a better knowledge of the geographical space, supplying subsidies to the most assorted sectors of environmental planning and 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.