La prise de conscience grandissante de la contamination des cours d'eau a entraîné l'établissement de réglementations de plus en plus strictes concernant les rejets urbains et la fixation d'objectifs de qualité à atteindre pour les milieux aquatiques. Cependant, l'échantillonnage ponctuel reste une limite importante dans l'estimation des flux de contaminants, et le besoin de suivis en continu est présent dans le milieu naturel et dans les réseaux d'assainissement urbains. Cette étude porte sur la quantification de la part des rejets urbains de l'agglomération grenobloise dans les flux totaux de matières en suspension (MES), nutriments (azote, phosphore), carbone organique et éléments traces métalliques (ETM) du milieu récepteur Isère (une rivière alpine). Ce travail s'est appuyé sur un réseau de mesures en continu de débits (Q) et de MES (par turbidimétrie) à l'amont et à l'aval de l'agglomération et sur une sonde spectrométrique à l'amont, associé à des campagnes de prélèvements réguliers et renforcés pendant les épisodes de crues. Des campagnes de mesures détaillées sur les principaux sous bassins du réseau d'assainissement ont été réalisées durant la période d'étude dans le cadre du schéma directeur d'assainissement de l'agglomération grenobloise. Le croisement de ces deux approches a permis de confronter les variations spatio-temporelles des MES, nutriments, carbone organique et ETM du réseau et du milieu récepteur en 2011 et 2012. Les flux sur ces deux années ont été établis afin de déterminer la contribution des rejets urbains dans les flux du milieu récepteur. La contamination en mercure a fait l'objet d'un suivi particulier du fait de la présence d'une source significative de mercure dans la région. Enfin, une réflexion sur l'amélioration des calculs de flux par l'utilisation de relations entre les ETM/carbone organique particulaire (COP) et un paramètre mesurable en continu (MES, Q) a été menée en parallèle de l'exploitation de ces résultats. Mots-clés : Matières en suspension ; Dynamique des flux ; Nutriments ; Eléments traces métalliques ; Mercure ; Rejets urbains (par temps de pluie et temps sec), sondes de turbidité et spectrométrique. / The growing awareness of the contamination of rivers has led to the establishment of more rigorous regulations related to urban waste, and to the setting of water quality objectives to be achieved for aquatic environment. However, grab sampling remains an important limitation for the estimation of contaminant flux, and the need for constant monitoring is present in both natural environment and urban sanitation. This study focuses on the quantification of the proportion of urban waste in the Grenoble area to the total flux of 1) suspended solids (TSS), 2) nutrients (nitrogen and phosphorus), 3) organic carbon and 4) metals trace element (MTE) of the receiving environment; the Isère (an alpine river). This work was supported by a network of continuous discharge measurements (Q) and TSS (turbidimetry), both upstream and downstream of Grenoble associated with regular sampling campaigns, with a higher measurement frequency during flood events. A spectrometric probe upstream was also placed upstream. Detailed measurement campaigns on major sub-basins of the sewerage network were performed during the study period as part of the sanitation master plan of Grenoble. The combination of these two approaches allowes to relate the spatio-temporal variations of TSS, nutrients, organic carbon and MTE in the urban water network of Grenoble and in the receiving environment (the Isère) for the years 2011 and 2012. Flows of the traced parameters have been established to determine the contribution of urban waste flows in the receiving environment, over these two years. Finally, a study on how to improve the flow calculations by the use of relations between MTE / particulate organic carbon (POC ) and a continuous measurable parameter (MES, Q ) was conducted in parallel with these results. Key words: suspended solids, Nutrients, metals trace element; Mercury; urban waste; turbidimetry and spectrometric probe

Change in hydrossedimentological system of the lower course of the São Francisco river, by controlling the flow, has changed the characteristics of the aquatic ecosystem as well as the suspended sediment load. The objective of this study was to evaluate the suspended sediment load in the São Francisco river Chanel, and settlement of aquatic macrophytes species in a section of the right bank under different soil bioengineering techniques. The study area comprises a margin stretch of the São Francisco River in its lower course, located in the Amparo de São Francisco Municipality, Sergipe. The botanical material collection followed conventional methods, being held from April 2014 to September 2015, in a total of four sampling time, two in the rainy season and two in the dry season. Suspended sediments load were evaluated through 03 years (2013, 2014 and 2015) in 20, 40 and 60% of the channel depth in five different transects oriented by the presence or absence of erosion control techniques, as identified: 1- Vegetated Slope; 2- Vegetated Riprap; 3- Eroded Slope; 4- Cribwall; and 5- Vetiver grass Line, considering three of them (2, 4 and 5) with soil bioengineering techniques. In the collected material 66 species was identified in 23 families, showing the its richness and diversity in a small stretch of the São Francisco River. In assessing the macrophytes population, the wet period showed greater species richness, and among soil bioengineering techniques, the Cribwall presented the highest number of individuals. The sediment load was statistically different for the three evaluated years, and the highest values were presented in 2013, when the river had the highest discharge. Among the treatments, the Eroded Slope presented at a depth of 20% the lowest contribution of suspended sediment and the Vegetated Riprap the lower sediment load rate compared to other techniques. The strong presence of aquatic macrophytes in the river contributed to the protection of the slopes toe by dissipating the energy of the ebb and flow of the waves. A progressive decrease in total sediment suspended load was found throughout evaluated period, due not only to reduced river discharge, but also the protection provided by adopted erosion control techniques. / O regime hidrossedimentológico do baixo curso do rio São Francisco, por meio do controle da vazão, tem alterado as características do ecossistema aquático, bem como a produção e transporte de sedimentos em suspenção. O objetivo desse estudo foi avaliar a produção de sedimentos em suspensão no canal do Rio São Francisco, e povoamento de macrófitas aquáticas em um trecho da margem direita submetida a diferentes técnicas de Engenharia Natural. A área de estudo compreendeu um trecho de talude da margem direita do Rio São Francisco no seu baixo curso, localizada no Município de Amparo do São Francisco, Sergipe. A coleta do material botânico seguiu os métodos convencionais, tendo sido realizada no período de abril de 2014 a setembro de 2015, totalizando quatro amostragens, duas no período chuvoso e duas no período seco. Sedimentos em suspensão foram avaliados no período de 03 anos (2013, 2014 e 2015) a 20, 40 e 60% de profundidade do canal, em cinco diferentes transectos, orientados pela presença ou ausência de técnicas de controle de erosão, assim identificados: 1- Talude Vegetado; 2- Enrocamento Vegetado; 3- Talude Erodido; 4- Parede Krainer; e 5- Cordão de Vetiver, sendo que em três trechos da margem (2, 4 e 5) foram implantadas técnicas de Engenharia Natural. Do material coletado foram identificadas 66 espécies, distribuídas em 23 famílias, mostrando sua riqueza e diversidade em um pequeno trecho do Rio São Francisco. Na avaliação do povoamento de macrófitas, o período do inverno apresentou maior riqueza dessas espécies e a Parede Krainer foi o tratamento que apresentou maior número de indivíduos. O aporte de Sedimentos em Suspensão diferiu estatisticamente para os três anos de coleta, com destaque para o ano de 2013, quando o rio apresentou a maior vazão. Entre os tratamentos, o Talude Erodido apresentou na profundidade de 20% o menor aporte de sedimentos em suspensão e, o Enrocamento Vegetado os menores valores quando comparada às outras técnicas. A forte presença de macrófitas aquáticas, na margem do rio, contribuiu para a proteção da base dos taludes por dissipar a energia do fluxo e refluxo das ondas. Constatou-se um decréscimo progressivo nos sedimentos em suspensão na comparação do período avaliado, devido não somente à redução da vazão do rio, como também à proteção conferida pelas técnicas adotadas de controle de erosão.

This thesis deals with the role of precipitation on erosion and landscape formation in the Nepal Himalayas. I investigate all successive steps involved in the erosion process: 1) Starting from the evaluation of precipitation datasets, 2) the transfer of precipitation to river discharge, 3) the mobilization and transport of material out of the mountain range, 4) and finally, erosion constrains over longer time-scales. I show that the dataset derived from the interpolation of rain gauge data performs best in the Himalayas. I demonstrate the importance of an until now unconsidered, major compartment of the Himalayan discharge cycle, which I identify as a fractured basement aquifer, and estimate the snow and ice melt contribution to the Himalayan rivers. Erosion rates calculated from suspended sediment fluxes and cosmogenic nuclide analysis range between 0.1 and 4 mm/yr. The rivers in the Nepal Himalayas are supply limited and the hillslopes as contributing source are transport limited. Last I show that over several thousand years erosion is not related with precipitation, but with relief. / Cette thèse porte sur le rôle des précipitations sur l’érosion et la formation des reliefs dans l’Himalaya Népalais. J’étudie chaque étape du processus d’érosion : 1) Evaluation des bases de données de précipitations, 2) Transfert des précipitations au débit fluvial, 3) Mobilisation et transport du matériel dans le bassin versant, et enfin 4) Mécanismes d’érosion sur de longues échelles de temps. Je montre que la base de données de précipitations obtenue par interpolation de données pluviométriques est la plus performante pour la région de l\'Himalaya. Je démontre l’importance d’une composante majeure, jusqu’alors ignorée, du cycle de débit de l’Himalaya que j’identifie comme étant les aquifères de sous-sol fracturé, et j’évalue la contribution de la fonte des neiges et glaces aux rivières Himalayennes. Les taux d’érosion calculés à partir des flux de sédiments en suspension et des analyses de nucléides cosmogéniques varient de 0.1 à 4 mm/a. Les rivières au Népal sont limitées par l’apport sédimentaire alors que les versants, en tant que source de sédiments, sont limités par le transport. Enfin, je montre que l’érosion sur des milliers d’années ne dépend des précipitations mais du relief. / Die vorliegende Arbeit beschäftigt sich mit der Rolle des Niederschlag bei Erosions- und Oberflächenprozessen im nepalesischen Himalaja. Ich untersuche die Abfolge der Erosionspsozesse im Himalaja: 1) Ausgehend von der Bewertung von Niederschlagsdatensätzen, 2) die Prozesse der Abflussbildung in Flüssen, 3) die Mobilisierung und Transport von Material, 4) und Erosionsraten über längere Zeiträume. Ich zeige, dass interpolierte Niederschlagsdaten die beste Qualität im Himalaya haben. Ich zeige auf, wie wichtig der bislang unberücksichtigt Grundwasserzwischenspeicher für die Abflussbildung im Himalaya ist und schätze den Anteil der Schnee-und Eisschmelze an dem Gesamtabfluss der Flüssen im Himalaja. Erosionsraten die mittels Schwebestofffracht und der Analyse kosmogener Nukluide berechnet wurden, liegen zwischen 0,1 und 4 mm pro Jahr. Der Sedimenttransport in den Flüssen in Nepal ist limitiert durch die Verfügbarkeit von transportierbarem Material, während der Transport und die Mobilisierung auf den Hängen durch die Verfügbarkeit von Wasser limitiert ist. Zudem sind die Erosionsraten über mehrere Jahrhundert nicht von der Niederschlagsverteilung abhängig sondern vom Relief.

Pursuant to the federal Clean Water Act (CWA), when a water body has been listed as impaired, Total Maximum Daily Loads (TMDLs) for the water quality constituents causing the impairment must be developed. A TMDL is the maximum daily mass flux of a pollutant that a waterbody can receive and still safely meet water quality standards. The development of a TMDL and demonstrating compliance with a TMDL requires pollutant load estimation. By definition, a pollutant load is the time integral product of flows and concentrations. Consequently, the accuracy of pollutant load estimation is highly dependent on the accuracy of runoff volume estimation. Runoff volume estimation requires the development of reasonable transfer functions to convert precipitation into runoff. In cold climates where a large proportion of precipitation falls as snow, the accumulation and ablation of snowpack must also be estimated. Sequential data assimilation techniques that stochastically combine field measurements and model results can significantly improve the prediction skill of snowmelt and runoff models while also providing estimates of prediction uncertainty. Using the National Weather Service's SNOW-17 and the Sacramento Soil Moisture Accounting (SAC-SMA) models, this study evaluates particle filter based data assimilation algorithms to predict seasonal snow water equivalent (SWE) and runoff within a small watershed in the Lake Tahoe Basin located in California. A non-linear regression model is then used that predicts suspended sediment concentrations (SSC) based on runoff rate and time of year. Runoff volumes and SSC are finally combined to provide an estimate of the average annual sediment load from the watershed with estimates of prediction uncertainty. For the period of simulation (10/1/1991 to 10/1/1996), the mean annual suspended sediment load is estimated to be 753 tonnes/yr with a 95% confidence interval about the mean of 626 to 956 tonnes/yr. The 95% prediction interval for any given year is estimated to range from approximately 86 to 2,940 tonnes/yr.

[Truncated abstract] The expansion of human populations in coastal land margins has resulted in major modifcations to estuarine ecosystems. The use of numerical models as predictive tools for assessing remediation strategies is increasing. However, parameterisation of physical processes, developed mainly through field investigations, is necessary for these models to be reliable and effective management tools. The physical processes in micro–tidal diurnal tidal systems are relatively unknown and the current study examines field measurements obtained from the upper Swan River estuary (Western Australia), a diurnal, partially mixed system during the summer when the freshwater discharge is negligible. The aims of the study were to characterise, temporally and spatially, the dominant physical processes and associated sediment resuspension. Variability at three dominant time-scales were examined: 1) sub–tidal oscillations (∼5 to 10 days) resulting from local and remote forcing; 2) tidal (∼ 24 hours) due to astronomical forcing; and 3) intra-tidal (∼2 to 3 hours) resulting from the interaction between tidal constituents. Circulation in estuaries is widely accepted in the literature to be dominated, in varying proportions, by tidal range, freshwater discharge and gravitational circulation. In the upper Swan River estuary sub–tidal oscillations were responsible for the largest upstream displacement of the salt wedge in the absence of freshwater discharge. Moreover, these sub–tidal fluctuations in water level modified the ‘classic’ estuarine circulation. The dynamics of diurnal tides are largely controlled by the tropic month, which oscillates at a slightly different period to the lunar month, resulting in the spring–neap tidal cycle to be sometimes different from syzygy. The phase lag between the diurnal (O1 + K1) and semi-diurnal (M2 + S2) constituents, at the seasonal time scale cause the maximum tidal range to be near the solstice. Over a 24–hour tidal cycle this phase lag is manifested as an intra–tidal oscillation that occurs on the flood tide. Turbidity events that last ∼1 to 2 hours occur during the intra–tidal oscillation, but are not related to maximum shear stress predicted from the mean flow characteristics. The increases in turbidity during the intra–tidal oscillation is, however, correlated with the near–bed Reynolds fluxes. During the intra–tidal oscillation advection opposes the estuarine circulation in the near–bed region, promoting vertical shear that results in destratifcation of the water column. The turbulent mixing generated at the interface and in the near–bed region coincide with resuspension events. Similar turbidity data have often been disregarded and documented as being ‘spikes’ based on the premise that the mean flow was below a critical level to resuspend sediment. Resuspension events were not simply related to mean processes and may be controlled by turbulent instabilities generated when tidal currents reverse during an intra-tidal oscillation

CAPES; CNPq / O Rio Ribeira de Iguape é o maior responsável pelo aporte de água doce e sedimentos em suspensão ao Complexo Estuarino-Lagunar de Iguape-Cananéia (CELIC), que abriga uma população de cerca de 200 botos-cinza. A bacia deste rio foi fortemente afetada por atividades mineradoras, que contaminaram os sedimentos ao longo de seu curso e em parte do estuário. Este estudo avaliou a variação espacial e temporal dos parâmetros físicos e químicos do ambiente, a biodisponibilidade do Fe‚ Zn‚ Mn‚ Co‚ Cu‚ Cr‚ Cd, Pb e Ni nos sedimentos e a acumulação destes elementos no fígado de 21 golfinhos da espécie Sotalia guianensis. A água e os sedimentos foram amostrados em 8 pontos ao longo do sistema em três diferentes coletas entre os anos de 2013 e 2014 e as amostras de tecidos foram obtidas através do monitoramento de praias entre 2009 a 2012. Algumas condições abióticas encontradas entre as porções norte e sul do sistema diferiram em grande grau, com maior destaque à salinidade, resistividade, OD, pH e ao aporte de nutrientes e metais. O Pb, Zn, Cu, Mg e Fe apresentaram altos valores nos sedimentos próximos a Iguape, sendo considerados como fortemente biodisponíveis. Ainda, a razão SEM/SVA dos íons metálicos Pb, Cd, Ni, Cu e Zn apontou maior toxicidade dos sedimentos desta região. Houve correlações positivas entre estes elementos indicando que provavelmente tenham as mesmas fontes, sendo provenientes do arraste realizado pelo Rio Ribeira de Iguape. No fígado dos golfinhos, as concentrações deram-se na seguinte ordem de grandeza: Fe>Zn>Cu>Mn>Cr>Pb>Ni>Co>Cd. O Fe e o Zn apresentaram as maiores variações entre os metais e o Pb teve a maior variação e média descritas para a espécie (1,94 μg g-1). Não foram observadas correlações no acúmulo dos metais entre os sexos e o comprimento corporal dos animais. No entanto, animais infantes apresentaram maiores concentrações de metais essenciais, estando estes valores ligados ao período de rápido crescimento pós-natal. Considerando-se o histórico local e os valores observados para a biodisponibilidade dos metais, o estudo ressalta a utilização do boto-cinza como sentinela sendo esta avaliação uma importante abordagem para o monitoramento ambiental uma vez que permite a medição direta da biodisponibilidade dos poluentes. A alta média observada para o chumbo nos botos pode refletir a contaminação ambiental local causada por atividades mineradoras e indicar uma possível transferência trófica, uma vez que a dieta é uma das principais vias da exposição ao elemento. / The Ribeira de Iguape river is the most responsible for the input of freshwater and sediments in suspension to the Estuarine-Lagoon Complex of Iguape-Cananéia (CELIC), which has a population of about 200 Guiana dolphins. The basin of this river was strongly affected by mining activities, which contaminating the sediments along its course and in part of the estuary. This study evaluated the spatial and temporal variation of physical and chemical parameters of the environment, the bioavailability of Fe, Zn, Mn, Co, Cu, Cr, Cd, Pb and Ni in the sediments and the accumulation of these elements in the liver of 21 dolphins of the species Sotalia guianensis. The water and sediment were sampled in 8 points throughout the system in three different samples between the years 2013 and 2014 and the tissue samples were obtained by monitoring of the beaches between 2009 and 2012. The trophic conditions found between the portions differ in great degree, most notably salinity, resistivity,DO, pH and the supply of nutrients and metals. The metals Pb, Zn, Cu, Mg and Fe showed high values in sediments near Iguape, being considered as strong bioavailable. The SEM/SVA reason for the metalic ions Pb, Cd, Ni, Cu and Zn showed greater toxicity of the sediments in this region. There were positive correlations between these elements indicating that they probably have the same sources, from the drag made by the Ribeira river. In the liver of the dolphins, the concentrations were given in the following order of magnitude: Fe>Zn>Cu>Mn>Cr> Pb>Ni>Co>Cd. The metals Fe and Zn showed higher values between metals and the Pb had the highest mean and variance ever described for the species (1.94 μg g-1). There were no correlations in the accumulation of metals between the sexes and the body length of the animals. However, infants showed higher concentrations of essential metals, and these values are related to the periode of rapid postnatal growth. Considering the local history and the bioavailability values observed for the metals, this study emphasizes the use of the Guiana dolphin as sentinel, this being an important approach for environmental monitoring once it allows direct measurement of the bioavailability of metals. The high mean of lead observed in the dolphings may reflect the local environmental contamination caused by mining activities and indicate a possible trophic transfer, since the diet is a major route of exposure to the element.

CAPES; CNPq / O Rio Ribeira de Iguape é o maior responsável pelo aporte de água doce e sedimentos em suspensão ao Complexo Estuarino-Lagunar de Iguape-Cananéia (CELIC), que abriga uma população de cerca de 200 botos-cinza. A bacia deste rio foi fortemente afetada por atividades mineradoras, que contaminaram os sedimentos ao longo de seu curso e em parte do estuário. Este estudo avaliou a variação espacial e temporal dos parâmetros físicos e químicos do ambiente, a biodisponibilidade do Fe‚ Zn‚ Mn‚ Co‚ Cu‚ Cr‚ Cd, Pb e Ni nos sedimentos e a acumulação destes elementos no fígado de 21 golfinhos da espécie Sotalia guianensis. A água e os sedimentos foram amostrados em 8 pontos ao longo do sistema em três diferentes coletas entre os anos de 2013 e 2014 e as amostras de tecidos foram obtidas através do monitoramento de praias entre 2009 a 2012. Algumas condições abióticas encontradas entre as porções norte e sul do sistema diferiram em grande grau, com maior destaque à salinidade, resistividade, OD, pH e ao aporte de nutrientes e metais. O Pb, Zn, Cu, Mg e Fe apresentaram altos valores nos sedimentos próximos a Iguape, sendo considerados como fortemente biodisponíveis. Ainda, a razão SEM/SVA dos íons metálicos Pb, Cd, Ni, Cu e Zn apontou maior toxicidade dos sedimentos desta região. Houve correlações positivas entre estes elementos indicando que provavelmente tenham as mesmas fontes, sendo provenientes do arraste realizado pelo Rio Ribeira de Iguape. No fígado dos golfinhos, as concentrações deram-se na seguinte ordem de grandeza: Fe>Zn>Cu>Mn>Cr>Pb>Ni>Co>Cd. O Fe e o Zn apresentaram as maiores variações entre os metais e o Pb teve a maior variação e média descritas para a espécie (1,94 μg g-1). Não foram observadas correlações no acúmulo dos metais entre os sexos e o comprimento corporal dos animais. No entanto, animais infantes apresentaram maiores concentrações de metais essenciais, estando estes valores ligados ao período de rápido crescimento pós-natal. Considerando-se o histórico local e os valores observados para a biodisponibilidade dos metais, o estudo ressalta a utilização do boto-cinza como sentinela sendo esta avaliação uma importante abordagem para o monitoramento ambiental uma vez que permite a medição direta da biodisponibilidade dos poluentes. A alta média observada para o chumbo nos botos pode refletir a contaminação ambiental local causada por atividades mineradoras e indicar uma possível transferência trófica, uma vez que a dieta é uma das principais vias da exposição ao elemento. / The Ribeira de Iguape river is the most responsible for the input of freshwater and sediments in suspension to the Estuarine-Lagoon Complex of Iguape-Cananéia (CELIC), which has a population of about 200 Guiana dolphins. The basin of this river was strongly affected by mining activities, which contaminating the sediments along its course and in part of the estuary. This study evaluated the spatial and temporal variation of physical and chemical parameters of the environment, the bioavailability of Fe, Zn, Mn, Co, Cu, Cr, Cd, Pb and Ni in the sediments and the accumulation of these elements in the liver of 21 dolphins of the species Sotalia guianensis. The water and sediment were sampled in 8 points throughout the system in three different samples between the years 2013 and 2014 and the tissue samples were obtained by monitoring of the beaches between 2009 and 2012. The trophic conditions found between the portions differ in great degree, most notably salinity, resistivity,DO, pH and the supply of nutrients and metals. The metals Pb, Zn, Cu, Mg and Fe showed high values in sediments near Iguape, being considered as strong bioavailable. The SEM/SVA reason for the metalic ions Pb, Cd, Ni, Cu and Zn showed greater toxicity of the sediments in this region. There were positive correlations between these elements indicating that they probably have the same sources, from the drag made by the Ribeira river. In the liver of the dolphins, the concentrations were given in the following order of magnitude: Fe>Zn>Cu>Mn>Cr> Pb>Ni>Co>Cd. The metals Fe and Zn showed higher values between metals and the Pb had the highest mean and variance ever described for the species (1.94 μg g-1). There were no correlations in the accumulation of metals between the sexes and the body length of the animals. However, infants showed higher concentrations of essential metals, and these values are related to the periode of rapid postnatal growth. Considering the local history and the bioavailability values observed for the metals, this study emphasizes the use of the Guiana dolphin as sentinel, this being an important approach for environmental monitoring once it allows direct measurement of the bioavailability of metals. The high mean of lead observed in the dolphings may reflect the local environmental contamination caused by mining activities and indicate a possible trophic transfer, since the diet is a major route of exposure to the element.