Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2018-02-07T13:54:23Z No. of bitstreams: 1 dissertação_Laura.pdf: 5408448 bytes, checksum: f3d1bfb2f5f04ffe5df9adae2d5c5946 (MD5) / Made available in DSpace on 2018-02-07T13:54:23Z (GMT). No. of bitstreams: 1 dissertação_Laura.pdf: 5408448 bytes, checksum: f3d1bfb2f5f04ffe5df9adae2d5c5946 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / O material particulado em suspensão (MPS) é formado principalmente por partículas originadas do intemperismo das rochas presentes na bacia, além de partículas orgânicas. O conhecimento acerca do MPS pode fornecer informações sobre proveniência, processos e influências antrópicas. Alterações na bacia de drenagem, como as relacionadas ao uso do solo e construções de barragens, influenciam principalmente na quantidade de material transportada, enquanto a urbanização sobretudo na qualidade. O presente trabalho buscou estabelecer a contribuição de MPS da bacia do rio Piabanha (RJ) para o rio Paraíba do Sul e caracterizá-la química e mineralogicamente, além de estabelecer diferenças temporais e espaciais na bacia, qualitativa e quantitativamente. Foram feitas sete coletas ao longo do ano de 2016, em três pontos da bacia, e as amostras tiveram seus valores de concentração, carga e fluxo de MPS calculados. Foram realizadas análises químicas por fluorescência de raios X e análises mineralógicas por difração de raios X, essas últimas acrescidas de quantificação pelo método de Rietveld. Os resultados encontrados indicaram variação sazonal na quantidade de sedimentos produzida (10‒1600 ton dia⁻¹ na foz) e também variação espacial, fruto principalmente das diferenças da cobertura e uso do solo ao longo da bacia. As barragens também se mostraram importantes na retenção de sedimentos. Os minerais encontrados no MPS foram caulinita, gibbsita, goethita, illita, feldspatos, quartzo, muscovita, anatásio e weddelita, sendo esta última mais presente na região urbanizada, funcionando como um traçador de influência antrópica. A caulinita foi o mineral mais representativo do MPS em todas as amostras (28‒55%), indicando um material significativamente intemperizado. As análises químicas mostraram predominância de SiO2 (35‒46%) e Al2O3 (25‒41%). Houve maior participação de P2O5 e Fe2O3 no período seco, relacionados direta ou indiretamente à influência antrópica na bacia, como lançamento de efluentes, contudo essa diferença sazonal foi vista principalmente nas áreas urbanizadas / The suspended particulate matter (SPM) is formed mainly by particles resulted from rock weathering, but also by organic ones. The knowledge of SPM is able to provide information about provenience, processes and anthropic influences. River basin alterations, like the ones related to land use and dam constructions, can change mainly the transported load’s quantity, while urbanization is related mostly to quality. The present study aimed to determine the SPM contribution from Piabanha river basin (RJ) to Paraiba do Sul river and characterize its mineralogy and chemistry, as well as set temporal and spatial variation, qualitatively and quantitatively. Samples were collected in three points of Piabanha basin, in seven different days of 2016, and concentration, load and flow values of SPM were calculated. The samples analysis included its chemistry (X-ray fluorescence) and mineralogy (X-ray diffraction), the last one with addition of quantification by Rietveld method. The results showed seasonal (10‒1600 ton day⁻¹ in the mouth) and spatial variation in sediments yield, due to differences in cover and land use along the basin. Dams also exposed their importance in sediments retention. Minerals found in SPM were kaolinite, gibbsite, goethite, illite, feldspars, quartz, muscovite, anathase and weddellite, with the last one more present in urban areas, working as a tracer of anthropic influence. Kaolinite was the most representative mineral of SPM in all samples (28‒55%), denoting a material associated to significant weathering. The chemical analysis showed SiO2 (35‒46%) and Al2O3 (25‒41%) predominance. P2O5 and Fe2O3 were higher in the dry period, related directly or indirectly to anthropic influence, like effluents release. However, this seasonal difference was observed mainly in urban areas.

[pt] A matéria orgânica particulada (MOP) em suspensão presente entre a Baía de Guanabara e o oceano costeiro foi caracterizada através de composição elementar (C e N), razões isotópicas (delta 13C e delta 15N) e marcadores moleculares (esteróis, n-álcoois e ácidos graxos) em dois períodos (verão e outono) ao longo de um transecto e de um fundeio de 25h. As assinaturas elementares (C/N = 5 a 23) e isotópicas (delta 13C = -27,7 a -16,2 por mil e delta 15N = 2,4 a 11,2 por mil) foram típicas de predomínio de matéria orgânica planctônica. Ácidos graxos (totais de 12,08 ± 7,78 Micrograma L–1 no verão e 22,06 ± 1,75 Micrograma L–1 no outono para o transecto; e de 13,47 ± 5,15 Micrograma L–1 no verão e 15,84 ± 3,61 Micrograma L–1 no outono para o fundeio de 25h) ocorreram como compostos de cadeia curta, mono- e poli-insaturados. Concentrações totais de esteróis variaram de 0,04 a 7,32 Micrograma L-1, com predominância de colesterol e fitoesteróis. n-álcoois foram um componente menos importante (0,01 a 5,67 Micrograma L-1). A abordagem multiparâmetros revelou a contribuição predominante de fontes autóctonas de MOP, o que reflete a influência da Baía de Guanabara sobre processos ecológicos na zona de transição aqui considerada. A contribuição fecal sobre a MOP também foi identificada, mas sendo um componente menos significativo, possivelmente pela diluição causada pelas fontes autóctonas ou pela degradação dos marcadores fecais. Além disso, a MOP de origem terrestre não é exportada da baía e, portanto, deve sofrer um processo de acúmulo nos sedimentos internos da baía. Isso suporta a necessidade de quantificar essa contribuição continental para melhor estabelecer o balanço de carbono na baía. / [en] Suspended particulate organic matter (POM) present between Guanabara Bay and the coastal ocean was characterized by elemental composition (C and N), isotopic ratios (delta13C and delta15N) and molecular markers (sterols, n-alcohols and fatty acids) in two periods (summer and fall) along a transect and a fixed station. Elemental (C/N of 5 to 23) and isotopic (delta13C= -27.7 to -16.2 per thousand and delta15N = 2.4 to 11.2 per thousand) signatures were typical for the predominance of planktonic organic matter. Fatty acids (totals of 12.08 ± 7.78 microgram L–1 in summer and 22.06 ± 1.75 microgram L–1 in the fall for the transect, and 13.47 ± 5.15 microgram L–1 in summer and 15.84 ± 3.61 microgram L–1 in the fall for the fixed station) were presente as short-chain, monoand poly-unsaturated compounds. Total sterol concentrations ranged from 0.04 to 7.32 microgram L–1, with the predominance of cholesterol and phytosterols. n-alcohols were a minor component (0.01 to 5.67 microgram L–1 ). The multi-proxy approach revealed an overwhelming contribution of autochthonous POM sources, reflecting the influence of the Guanabara Bay outflow on ecological processes in the transition zone considered herein. Fecal contribution to POM was also identified, albeit as a less significant component, possibly due to dilution caused by autochthonus sources or degradation of fecal markers. Moreover, the terrestriallyderived POM was not exported from the bay and, therefore, must experience an accumulation process in the inner bay sediments. This supports the need to quantify such continental contribution to better establish the carbon balance in the bay.

動機與目的：傳統的統計迴歸模式假設觀測值的不確定性來自於隨機現象，而模糊迴歸則考慮不確定性來自於多重隸屬現象。不同的模型建構所得到的估計值也不一致。如何衡量模型的優劣程度，至今仍沒有一套嚴謹的標準。 研究方法：本研究以區間模糊數建構模糊迴歸模式，如此一來對樣本的解釋方式將更為貼近現實，並提出一套區間模糊數距離測度，以衡量估計值與實際值之間的差距。實證分析中（懸浮微粒PM_10濃度預測、台灣加權股價指數預測），我們藉由此距離測度衡量二維模糊迴歸與傳統二項最小平方法對於樣本的配適性。 創新與推廣：提出區間模糊數距離衡量估計值與原樣本之差異程度。在符合傳統統計迴歸精神之下，當距離最小就是差異最小的估計，最能符合所抽取的樣本，也是最佳估計。 重要發現：利用本區間模糊數距離測度，我們發現二維模糊迴歸方法比起傳統二項最小平方法更有效率且廣義殘差（generalized residual）將更小。 結論：過去以來，我們對於模糊迴歸架構一直都沒有完整的衡量標準。文中我們定義區間模糊數區間距離與平均距離，並推導賦距空間等性質。結合實例分析及應用，建構一合適模糊迴歸模式，以利統計決策分析參考。 / Objective: This study concerns how to develop effective fuzzy regression models. In the literature, little is addressed on how to evaluate the effectiveness of fuzzy regression models developed with different regression methods. We consider this issue in this work and present a framework for such evaluation. Method: We consider fuzzy regression models developed with different regression approaches. A method to evaluate the developed models is proposed. We then show that the proposed method possesses desirable mathematical properties and it is applied to compare the two-dimensional regression method and the traditional least square based regression method in our case studies: predicating the concentration of and the volatility of the weighted price index of the Taiwanese stock exchange. Innovation: We propose a new metric to define a distance between two fuzzy numbers. This metric can be used to evaluate the performance of different fuzzy regression models. When a prediction from one model is closest to the sample data measured in terms of the proposed metric, it can be recognized as the optimal predication. Results: Based on the proposed metric, it can be obtained that the two-dimensional fuzzy regression method is better than the traditional least square based regression method. Especially, its resulting generalized residual is smaller. Conclusion: In the literature, no unified framework has been previously proposed in evaluating the effectiveness of developed fuzzy regression models. In this work, we present a metric to achieve this goal. It facilitates the work to determine whether a fuzzy regression model suitably fits obtained samples and whether the model has potential to provide sufficient accuracy for follow-up analysis in a considered problem.

Douze contaminants émergents (composés pharmaceutiques, pesticides et hormones) ont été quantifiés et extraits de l'eau de rivières et d’échantillons d'eaux usées municipales. La séparation des solides en suspension est effectuée par filtration des échantillons d'eau. L'effet de filtration sur les concentrations de contaminants dissous a été évaluée afin de minimiser les pertes de composés cibles. Les échantillons ont été lyophilisés et ont été extraits en deux cycles par ultrasons combinés avec une étape de nettoyage sur cartouche d’extraction de type C18. La quantification a été réalisée en utilisant la spectrométrie de masse. Les recouvrements de la méthode pour tous les composés ont varié de 68 à 112% dans toutes les matrices étudiées, sauf pour le sulfaméthoxazole et le diclofénac où des recouvrements plus modestes ont été obtenus (38 à 85%). Les limites de détection pour les 12 analytes dans les sédiments et particules en suspension (SPM) de la rivière variaient de 0,7 à 9,4 ng g-1 et de 21 à 92 ng g-1, pour les échantillons SPM de station d'épuration. Tous les contaminants émergents cibles ont été détectés à des concentrations variant de 3 à 5440 ng g-1 dans les matrices étudiées, les concentrations les plus élevées ont été observées dans les échantillons SPM de stations d'épuration. Une partie importante de certains de ces contaminants est clairement associée aux sédiments de rivière ou aux particules en suspension. L’optimisation des processus de traitement de l'eau et le devenir environnemental doit absolument tenir compte de la fraction de contaminants qui liée à des particules si on espère avoir un bilan de masse raisonnable. / We developed a protocol to quantify 12 emerging contaminants (pharmaceuticals and hormones) and pesticides extracted from suspended particulate matter (SPM) of river water and municipal wastewaters samples. The separation of suspended solids was carried through filtration of water samples. We tested a series of 6 different filter types. The effect of filtration on the concentrations of dissolved contaminants was evaluated in order to minimize losses of target compounds. The river bottom sediments samples were lyophilized and both SPM and sediment samples were subjected to ultrasonic extraction combined with C18 cartridge clean-up. Quantifications were realized using mass spectrometry. The overall method recoveries of all compounds ranged from 38 to 112 % in all studied matrices, poor recoveries were achieved for sulfamethoxazole and diclofenac (recoveries for all other compounds in the wastewater treatment plant (WWTP) samples were 68 to 111%). The detection limits in sediments and SPM from river samples for the 12 analytes varied from 0.7 to 9.4 ng g-1 and from 21 to 92 ng g-1 for WWTP SPM samples. All target emerging contaminants were detected with concentrations ranging from 3 to 5440 ng g-1 in the studied matrices, with the highest concentrations observed in WWTP SPM samples. A significant portion of some of those contaminants is clearly associated with bottom sediments or suspended particulates. Optimization of water treatment processes and environmental fate must absolutely consider the fraction of contaminants which is particulate-bound if one hopes to have a reasonable mass balance.

Douze contaminants émergents (composés pharmaceutiques, pesticides et hormones) ont été quantifiés et extraits de l'eau de rivières et d’échantillons d'eaux usées municipales. La séparation des solides en suspension est effectuée par filtration des échantillons d'eau. L'effet de filtration sur les concentrations de contaminants dissous a été évaluée afin de minimiser les pertes de composés cibles. Les échantillons ont été lyophilisés et ont été extraits en deux cycles par ultrasons combinés avec une étape de nettoyage sur cartouche d’extraction de type C18. La quantification a été réalisée en utilisant la spectrométrie de masse. Les recouvrements de la méthode pour tous les composés ont varié de 68 à 112% dans toutes les matrices étudiées, sauf pour le sulfaméthoxazole et le diclofénac où des recouvrements plus modestes ont été obtenus (38 à 85%). Les limites de détection pour les 12 analytes dans les sédiments et particules en suspension (SPM) de la rivière variaient de 0,7 à 9,4 ng g-1 et de 21 à 92 ng g-1, pour les échantillons SPM de station d'épuration. Tous les contaminants émergents cibles ont été détectés à des concentrations variant de 3 à 5440 ng g-1 dans les matrices étudiées, les concentrations les plus élevées ont été observées dans les échantillons SPM de stations d'épuration. Une partie importante de certains de ces contaminants est clairement associée aux sédiments de rivière ou aux particules en suspension. L’optimisation des processus de traitement de l'eau et le devenir environnemental doit absolument tenir compte de la fraction de contaminants qui liée à des particules si on espère avoir un bilan de masse raisonnable. / We developed a protocol to quantify 12 emerging contaminants (pharmaceuticals and hormones) and pesticides extracted from suspended particulate matter (SPM) of river water and municipal wastewaters samples. The separation of suspended solids was carried through filtration of water samples. We tested a series of 6 different filter types. The effect of filtration on the concentrations of dissolved contaminants was evaluated in order to minimize losses of target compounds. The river bottom sediments samples were lyophilized and both SPM and sediment samples were subjected to ultrasonic extraction combined with C18 cartridge clean-up. Quantifications were realized using mass spectrometry. The overall method recoveries of all compounds ranged from 38 to 112 % in all studied matrices, poor recoveries were achieved for sulfamethoxazole and diclofenac (recoveries for all other compounds in the wastewater treatment plant (WWTP) samples were 68 to 111%). The detection limits in sediments and SPM from river samples for the 12 analytes varied from 0.7 to 9.4 ng g-1 and from 21 to 92 ng g-1 for WWTP SPM samples. All target emerging contaminants were detected with concentrations ranging from 3 to 5440 ng g-1 in the studied matrices, with the highest concentrations observed in WWTP SPM samples. A significant portion of some of those contaminants is clearly associated with bottom sediments or suspended particulates. Optimization of water treatment processes and environmental fate must absolutely consider the fraction of contaminants which is particulate-bound if one hopes to have a reasonable mass balance.

Este trabalho foi desenvolvido objetivando a determinação e a avaliação dos perfis temporais da concentração de alguns elementos químicos potencialmente tóxicos presentes no material particulado em suspensão (MPS) no interior de uma pequena indústria de fundição de metais bronze, ferro e alumínio que, em concentrações elevadas, podem acarretar sérios riscos à saúde do trabalhador. Para isso foi utilizado um amostrador temporal de MPS, que coleta amostras de aerossóis em intervalo de tempo pré-programados, separando-os por tamanho: (a) fração fina ou respirável (partículas com diâmetro aerodinâmico menor que 2,5 m, MP2,5) e (b) fração grossa ou inalável (entre 2,5 a 10 m, MP10-2,5), durante todo o período do processo de fundição (da fusão à moldagem). As amostras coletadas, na forma de faixas (strips) sobre um filtro (fração fina) e sobre um impactador (fração grossa), foram analisadas pela técnica de fluorescência de raios X por dispersão de energia (EDXRF), utilizando na excitação um tubo de raios X com alvo de Mo e e na detecção dos raios X característicos um detector semicondutor de Si(Li) acoplado a um analisador de pulsos multicanal, interpretando-se posteriormente os espectros de raios X obtidos pelo aplicativo AXIL. Para algumas amostras também foi feita uma análise com microscópio eletrônico de varredura (SEM/EDS) para se conhecer a morfologia dos particulados. Deste modo foi possível determinar a concentração de elementos químicos potencialmente tóxicos presentes em um ambiente de uma pequena indústria de fundição de metais, mostrando que o momento mais crítico dessa atividade foi o da moldagem e também determinar a forma do MPS. Na fundição do bronze e ferro, as concentrações dos elementos Cr, Mn, Ni e Pb, principalmente na fração fina no momento de moldagem, mostraram-se muito superior aos limites recomendados pelas agências brasileira e norte-americana. Apesar de não haver limites recomendados para o elemento Zn, foi verificada uma alta concentração principalmente na concentração na fração fina, o mesmo sucedendo para o Cu. Com respeito a fundição de alumínio, foi observado altas concentrações principalmente de Zn e Cu, somente na fração fina, não ocorrendo na fração grossa. Pelos resultados obtidos pode-se concluir que os trabalhadores estão sujeitos a condições insalubres de trabalho nesse tipo de ambiente, aconselhando-se o uso permanente de equipamentos adequados de proteção visando de preferência a fração fina, assim como um monitoramento constante desses elementos químicos durante todas as etapas do processo de fundição, principalmente na de moldagem / The aim of this work was to evaluate the chemical concentration of some potentially toxic inorganic chemical elements and the time profiles in fine (PM2.5, particles up to 2.5 m) and coarse (PM2.5-10, particles from 2.5 to 10 m) suspended particulate matter (SPM) inside a small foundry plant - bronze, iron and aluminium -, in which at high concentrations turns a healthy concern. For these purpose, a rotating streaker airparticulate sampler for sampling during all day foundry activity was utilized. Fine SPM was collected on a filter and coarse SPM in turn by an impactor. The collected samples were analyzed by energy dispersive X-ray fluorescence (EDXRF) technique employing a Mo target tube in the excitation, and the detection was carried out through Si(Li) semiconductor detector coupled to multichannel analyser, deconvolutting the X-ray spectra with AXIL software help. It was also carried out particulated morphological analysis by scanning electron microscopy with energy dispersive X-ray spectrometer coupled (SEM/EDS). In this manner, the inorganic chemicals content were determined in the small foundry allowing concluding that the moulding step is the critical one taking into account the amount of pollutant released. During bronze and iron melting, the Cr, Mn, Ni and Pb contents in SPM were higher than allowed values by Brazilian and United States legislations. It was also verified a high Zn and Cu content, mainly in the fine suspended particulate matter, although these elements are not contemplated by national nor international laws. Thus, due to this unhealthy environmental working conditions inside the small foundry plant,a proper individual protection equipment is mandatory mainly for fine suspended particulate matter, and a constant air pollutant monitoring in foundry plants is demanded, mainly during the moulding step

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / The Amazon river, located in northernBrazil, discharges between 80,000 and 250,000 m3s-1 of water onto the adjacent shelf, creating a plume of brackish water that extends hundreds of kilometers away from the river mouth. This river also carries a large amount of fine sediments to the ocean where fluid mud has been found in the topset and upper foreset layers of the subaqueous delta formed on the mid-shelf. One of the main goals of this dissertation is to describe how turbulence and suspended sediment concentration vary along the Northern Channel of the Amazon river. Water column measurements were carried out in October 2008 at six anchor stations (P1, P3, P5, P6, P8 e P9) located seaward of the river mouth; P1 and P9 were 125 km apart. Each station was occupied during 13 hours during which current speed and direction were continuously sampled with a 600 kHz Teledyne-RDI ADCP; hourly profiles of temperature, salinity, turbidity and depth were also obtained. Water samples were collected for determination of Suspended Particulate Matter (SPM) concentration and calibration of the turbidity sensor. Current speed reached values above 1.5 m s1 in the along-channel direction (NE-SW); a remarkable ebb-flood asymmetry was observed and flows were strongly ebb-dominated. Throughout the water column, SPM concentration at stations P1 and P3 varied between 100 and 300 mg L1 in association with the presence of freshwater. In contrast, a strong salinity gradient was observed between stations P6 and P9, coinciding with the occurrence of concentrations of SPM above 10 g L-1 (fluid mud). At stations P3, P5 and P6, interface between freshwater from the Amazon river and salt water from the continental shelf, shear stresses wereestimated through four diferents methods: Reynolds, Turbulent Kinetic Energy (TKE), modified TKE and Quadratic Law; in the nearbed region (3 mab) the computed values varied between 0 and 3 Pa. At the three stations (P3, P5 and P6) the lowest and the highest shear stress values were obtained through, respectively, the Reynolds and the TKE methods. Over the whole water column turbulence intensity was estimated through the standard deviation of the turbulent component of the along-channel current velocity (root-mean square of u); from these values, it was estimated the turbulent dissipation of energy (G), whose values at 3 mab varied between zero and 20 s1.

L’anticipation et l’adaptation de nos sociétés aux bouleversements résultants du changement climatique sont aujourd’hui des questions majeures guidant les activités humaines et l’action publique. Néanmoins, la prévision reste un défi essentiel en raison des fortes incertitudes existantes et il est primordial de continuer à progresser dans la compréhension des mécanismes à l’origine de ces bouleversements. Au sein du cycle hydrologique, le réservoir de surface (incluant les lacs, les rivières et les plaines d’inondation) occupe une place importante car il est l’une des principales ressources en eau des écosystèmes et des populations. Or, la dynamique des stocks d’eau de surface est toujours mal connue aux échelles régionale et globale, du fait de l’absence de mesures pluriannuelles d’extension et de hauteur d’eau des zones inondées, et de la prise en compte limitée de ces variables dans les modèles hydrologiques et hydrodynamiques. La télédétection spatiale offre désormais la possibilité d’effectuer un suivi des stocks d’eau de surface en utilisant la complémentarité entre l’imagerie multi-spectrale, permettant de cartographier les étendues inondées, et l’altimétrie radar fournissant des séries temporelles de hauteur d’eau des hydro-systèmes continentaux. L’objectif de ma thèse est de tirer le meilleur parti de la complémentarité entre les différents types d’observations spatiales pour évaluer les ressources en eau du réservoir de surface et mesurer la dynamique des transferts d’eau des continents aux océans, et son impact sur la zone côtière en utilisant les concentrations de matières en suspension comme traceur des masses d’eau. Depuis le milieu des années 1990, la multiplication des missions multi-spectrales à moyenne résolution (< 1 km de résolution spatiale) et des altimètres radars à haute précision (comprise entre 10 et 30 cm) permet de réaliser un suivi hebdomadaire à mensuel des volumes d’eau de surface dans les grands bassins fluviaux. / The anticipation and adaptation of our societies to the upheavals resulting from climate change are today major issues guiding human activities and public action. Nevertheless, the forecast remains a key challenge because of the strong uncertainties that exist and it is essential to continue to progress in understanding the mechanisms behind these upheavals. Within the hydrological cycle, the surface reservoir (including lakes, rivers and floodplains) occupies an important place as it is one of the main water resources of ecosystems and populations. However, the dynamics of surface water stocks are still poorly known at the regional and global scales, due to the absence of multi-year measures of extension and water depth of the flooded areas, and the limited consideration of these variables in hydrological and hydrodynamic models. Satellite remote sensing now offers the possibility of monitoring surface water stocks by using the complementarity between multispectral imagery, allowing to map flooded areas, and the radar altimetry providing time series of water depths of continental hydro systems. The aim of my thesis is to make the most of the complementarity between the different types of spatial observations to evaluate the water resources of the surface reservoir and to measure the dynamics of water transfers between land and ocean, and its impact on the coastal zone using suspended particulate matter as tracer of water bodies. Since the mid-1990s, the multiplication of multispectral missions with medium resolution (<1 km of spatial resolution) and high-precision radar altimeters (between 10 and 30 cm) makes it possible to carry out weekly-to-monthly monitoring of volumes surface water in large river basins.

La connaissance de la dynamique des matières en suspension (MES) et des turbidités en milieu côtier est un élément clé pour comprendre les écosystèmes marins. Les processus de floculation/défloculation représentent des mécanismes essentiels contrôlant la dynamique des caractéristiques physiques des MES et, par conséquent, leur devenir dans l’environnement. Cette thèse a pour objectif de mieux comprendre la caractérisation des MES et leur variabilité de l’échelle tidale à l’échelle annuelle en mer côtière, en réponse aux différents forçages hydrodynamiques, hydrologiques et biologiques ayant lieu à l’interface entre estuaire et baie. À cette fin, des capteurs optiques et acoustiques ont été déployés in situ, lors de 6 campagnes en mer réalisées en 2016, en vue de caractériser et de quantifier les MES dans la colonne d’eau, à la sortie de l’embouchure de l’estuaire de Seine (France). Une analyse critique des mesures granulométriques issues du LISST-100X est proposée. Un travail de quantification des incertitudes de mesure associées à l’estimation de la concentration en MES a mis en avant le risqué lié à un rinçage insuffisant des filtres et a conduit à définir une masse minimum à filtrer, de l'ordre de 10 mg, quelle que soit la concentration. Ce travail a notamment permis de proposer une méthode d’estimation d’un volume optimal de filtration basée sur une mesure préalable de turbidité de référence. Les mesures à haute fréquence ont montré que la dynamique des caractéristiques physiques des MES en termes de concentration et de taille médiane sont contrôlées par le cycle advection-floculation-sédimentation-remise en suspension. Ces résultats ont permis de hiérarchiser les paramètres de contrôle des processus de floculation. La turbulence a été identifiée comme le principal paramètre de contrôle à l’échelle tidale et semi-lunaire, la taille médiane maximale des flocs étant inversement corrélée à l’intensité des courants. À l’échelle saisonnière, la variation des caractéristiques des MES (taille, densité, vitesse de chute) est liée à la variabilité du contenu en matière organique (MO), avec une floculation favorisée quand le taux de MO particulaire augmente. Ces flocs plus grands et moins denses sont également plus résistants à la fragmentation induite par cisaillement turbulent. Ces travaux ont également permis de discuter le concept de structuration fractale des flocs.La dynamique de la dimension fractale, déterminée en combinant des données in situ de concentration en MES et de distribution en classe de taille, peut traduire des variations de composition des MES, mais peut aussi résulter d'incertitudes de mesure associées aux instruments. Ces dernières sont discutées dans cette thèse. La variabilité saisonnière des caractéristiques des MES est plus prononcée au large que dans la zone sous influence de l’estuaire de Seine. À partir des observations ponctuelles en Baie de Seine et d’une série de mesure long terme dans la zone côtière belge acquise par le laboratoire RBINS, les méthodes acoustiques et optiques sont combinées. Ces dernières ont mis en avant une augmentation de la rétrodiffusion acoustique lorsque la densité moyenne des flocs diminue. / The knowledge of suspended particulate matter (SPM) and turbidity dynamics in coastal waters is essential for studying marine ecosystems. Flocculation/deflocculation processes are crucial mechanisms controlling the dynamics of SPM physical characteristics and thus, the fate of these SPM in the environment. This PhD thesis focuses on the SPM characteristics and their dynamics in coastal waters, from tidal to annual scales, in response to hydrodynamic, hydrological and biological forcing that take place at the interface between estuaries and coastal seas. To this end, optical and acoustic sensors were deployed in situ through 6 field campaigns in 2016, in order to characterize and quantify SPM in the water column, near the mouth of the Seine estuary (France). A critical analysis of LISST-100X measurements in coastal waters is presented. The quantification of uncertainties on SPM concentration measurements is investigated: it highlights the crucial effect of salt retention, and the need for a minimum mass to filter, around 10 mg. A method for estimating an optimal filtration volume based on a reference turbidity measurement is proposed. High frequency measurements show that the dynamics of SPM and median diameter are controlled by the advection-flocculationsedimentation-resuspension cycle.These results allow to classify the factors controlling flocculation processes. Turbulence is identified as the main factor at the semi-diurnal and semi-lunar tidal scales, as the maximum median size of flocs decreases when the tidal currents intensify.At the seasonal scale, the variation of SPM characteristics (size, density, settling velocity) is correlated to the variability of the organic matter (OM) content: in particular, flocculation is enhanced by an increase of the particular OM fraction. The resulting larger and lesser dense flocs are also more resistant to the fragmentation induced by shear. This work also investigates the fractal approach applied to flocs. The fractal dimension variability, calculated by combining in situ data of SPM concentration and particle size distribution, can be associated to variations of the SPM composition, but can also result from uncertainties linked to instrument limitations. The latter are discussed in this PhD thesis. The seasonal variability of SPM characteristics is more pronounced offshore than at the mouth of the Seine estuary. From short-term observations in the Seine Bay and from long-term series in the Belgian coastal zone provided by the RBINS, optical turbidity and acoustic backscatter measurements are combined. They highlight an increase of the acoustic backscatter intensity when mean floc density.

<p>This thesis presents models applicable for aquatic ecosystems. Geographical Information Systems (GIS) form an important part of the thesis. The dynamic mass balance models focus on nutrient fluxes, biotic/abiotic interactions and operate on different temporal and spatial scales (site, local, regional and international). The relevance and role of scale in mass balance modelling is a focal point of the thesis.</p><p>A mesocosm experiment was used to construct a model to estimate the nutrient load of phosphorus and nitrogen from net cage fish farming (i.e., the site scale). The model was used to estimate what feeding conditions that are required for a sustainable aquaculture scenario, i.e., a zero nutrient load situation (a linkage between the site scale and the regional scale). </p><p>A dynamic model was constructed for suspended particulate matter (SPM) and sedimentation in coastal areas (i.e., the local scale) with different morphometric characteristics and distances to the Sea. The results demonstrate that the conditions in the Sea (the regional and international scale) are of fundamental importance, also for the most enclosed coastal areas.</p><p>A foodweb model for lakes was transformed and recalibrated for Baltic Sea conditions (i.e., the international scale). The model also includes a mass balance model for phosphorus and accounts for key environmental factors that regulate the presuppositions for production and biomasses of key functional groups of organisms. The potential use of the new model for setting fish quotas of cod was examined.</p><p>For the intermittent (i.e., regional) scale, topographically complex areas can be difficult to define and model. Therefore, an attempt was made to construct a waterscape subbasin identification program (WASUBI). The method was tested for the Finnish Archipelago Sea and the Okavango Delta in Botswana. A comparison to results from a semi-random delineation method showed that more enclosed basins was created with the WASUBI method.</p>