Qualitative and microcosm models were used to predict effects of herbicide application for control of Myriophyllum spicatum. Predictions were compared to data from Pat Mayse Lake, a Texas reservoir, where localized areas were treated with endothall. Although milf oil was temporarily eliminated, when endothall was used according to manufacturer's directions, no ecologically significant direct or indirect effects were observed on nontarget species or abiotic water quality. Comparisons of the predictions with field data confirmed the capabilities of this approach for estimating risk and emphasizing the importance of identifying regulating or driving factors that modify environmental impacts of aquatic weed control programs so they can be incorporated into future risk assessments.

Production dynamics in the phytoplankton community of a mesotrophic Texas reservoir were measured weekly over a four month period using 14C incubation and ATP assay methodologies. Assimilation values of 14C ranged from 0.2 to 45 ug C 1 hr1 - . Significant positive and occasionally negative changes in biomass (i.e. viable organic carbon) were observed in short term (4 hr) in situ incubations juxtapo-sitioned with the 14C experiments; viable organic carbon production, estimated with the ATP assay, ranged from -25 to +50 ug C 1l1hr1. Carbon assimilation and biomass changes did not correlate in either short term (4-5 hr.) or over the study period (6 months). However, weekly biomass trends were predicted by relative positive or negative biomass changes in the short term incubations. Biomass measurements gave a more sensitive insight into production dynamics in the phytoplankton community than did carbon assimilation measurements.

The vertical and lateral aggradation of terminal and crevasse splay deposits in continental environments can form extensive fine-grained, sheet-like sandstone bodies which may form an important but often overlooked component of subsurface hydrocarbon reservoirs. This study examines splay deposits on the modern day Distributive Fluvial System (DFS), of the Parapeti River, Bolivia, using remote sensing techniques and geographic information system (ArcGIS) to characterise both lateral and terminal modern splay systems. Overall emphasis is given to the spatial and temporal relationship between sedimentary facies at the distal part of the Parapeti DFS over the past 42 years. A sedimentary facies evolution model is created to account for the development of the distal part of the Parapeti DFS. A number of splay deposits have formed and developed during this period and the Parapeti channel has prograded ~17 km basinward by short-term deposition in one location, followed by either repeated local avulsion or coeval downstream progradation of the terminal channel and associated splays. Rock record examples from the Miocene aged Huesca DFS in the Ebro Basin, Spain were studied in order to compare dimensional data as well as understand the relationship between splays and associated channel bodies. The study area is characterized by thin sandstone sheets (0.05-2.6 m thick; 100s m wide) interbedded with mudstones and siltstones interpreted to represent a terminal splay complex based on the distribution of facies, architectural elements and paleocurrent data. There is a strong resemblance between the model developed for the Parapeti DFS and the splay complexes recorded in the Miocene Huesca DFS. Sedimentary models are proposed in which terminal splay formation through avulsions is considered to be the dominant process in the distal parts of both systems. Avulsions control sediment distribution, resulting in stacking of splay deposits to form extensive sandstone sheets. However, it is suggested that different types of avulsion successions (i.e. progressive or abrupt) recognized by previous workers, may not be distinguishable in the rock record as they can produce a similar stratigraphic signature.

Small water reservoirs in urban areas have important landscape-forming and environmental roles. However, numerous anthropogenic activities can influence the water quality in these urban ponds. This thesis evaluates and compares the water quality in selected ponds in Prague area (Motol, Stodůlky, Háje) by means of regular water monitoring between May and November 2013. Parameters commonly used as indicators of anthropogenic load were monitored (NO3 - , NH4 + , PO4 3- , Cl- , dissolved oxygen, chemical oxygen demand) and supplemented with the investigation of other chemical and physico-chemical parameters (alkalinity, acidity, water hardness, pH, Ca2+ , NO2 - , specific conductivity). Data were evaluated using Czech technical norm (ČSN - EN 75 7221), which defines five categories of surface water quality. Our data indicated that surface water from reservoirs in Motol exhibited the best water quality (1st category), reservoirs from Stodůlky were slightly polluted and reservoirs from Háje exhibited the poorest water quality (with some parameters exhibiting values corresponding to the 4th category). We found statistically significant correlations between the alkalinity, water hardness, COD and concentrations of NO3 - , Ca2+ , Cl- and PO4 3- . Moreover, numerous parameters are dependent on cumulative...

This diploma thesis deals with monitoring of water quality in the reservoirs which form the Litovicko- Šárecká cascade. It is a cascade of ponds, waterworks and retention reservoirs situated on the Litovicko-Šárecký stream and is composed of 9 major reservoirs. These reservoirs have different functions: from landscaping, retention, biological as well as recreation: fishing and swimming. Many of these reservoirs flow through human settlements, which have a negative impact on the quality of water within the whole cascade. The goal of this thesis is to monitor physical and chemical indicators of water as well as to determine the composition of phytoplankton populations, assess the state of water depending on the human activities in the basin and also to monitor how has the water quality changed in time and what are the main pollution sources. The water quality was determined from 11 samples collected with monthly intervals during March 2012 to May 2013. Samples were collected on all the reservoirs from the inflow, in the middle and at the outflow for chemical analysis and only from the middle for biological analysis. The following indicators were monitored: temperature, pH, conductivity, dissolved oxygen, indicators of neutralization capacity (ZNK8.3 a KNK4.5), hardness, CODMn, the concentration of...

Afin de satisfaire à la croissance des besoins énergétiques mondiaux, le domaine des réservoirs carbonatés très enfouis (Deeply Buried Reservoirs) constitue une cible privilégiée pour l'exploration et l'exploitation pétrolière. La préservation, dans les roches carbonatées, de propriétés pétrophysiques favorables (porosité / perméabilité) à grande profondeur peut alors conduire à l'existence d'un réservoir profondément enfoui (Deeply Buried Reservoir, DBR). Les processus chemo-mécaniques impliqués dans la diagénèse d'enfouissement des réservoirs carbonatés sont cependant encore mal contraints et il y a un manque crucial de données expérimentales sur ce sujet. Afin de mieux comprendre ces processus et de déterminer comment la porosité et la perméabilité peuvent être préservées aux profondeurs des DBR (>4000m), un dispositif expérimental novateur et le protocole associé ont été développés. Ce dispositif expérimental permet à la fois de reproduire les conditions de pression / contraintes / température des DBR (80°C, contrainte de confinement de 60 MPa et contrainte déviatorique jusqu'à 40 MPa) et de faire circuler des fluides de diverse nature dans les échantillons. Des échantillons d'un calcaire bioclastique induré (calcaire de Massangis) ont été testés via une approche multidisciplinaire : déformations mécaniques de fluage, suivi de l'évolution de la chimie du fluide de circulation et analyses pétrographiques et pétrophysiques des roches. Il a ainsi été démontré qu'il existe une relation importante entre la contrainte mécanique à laquelle est soumise la roche, les interactions thermodynamiques fluide-roche et l'évolution des propriétés pétrophysiques. Le processus principal responsable des déformations de fluage des roches carbonatées lors de l'enfouissement a été déterminé comme étant la pression-dissolution sous contraintes, processus chemo-mécanique impliqué dans la perte de porosité lors de la diagénèse de profondeur. Les expériences menées l'ont été avec différentes conditions de circulation de fluide (saturation et circuit ouvert) et différentes compositions chimiques du fluide ont été testées (eau météorique, eau météorique additionnée de phosphates et saumure). De même, les effets des hydrocarbures et de leur timing de mise en place ont été étudiés. Les résultats obtenus ont permis d'affirmer que, en présence de fluide météorique, la PSC se produit à l'échelle micritique, et résulte en la précipitation de calcite sur les faces libres de la calcite, provoquant le blocage de la microporosité. La préservation des macropores permet de conserver la perméabilité. L'addition de phosphates dans le fluide de circulation résulte en l'inhibition de la PSC tandis que l'augmentation de la salinité par l'ajout de NaCl accélère ce mécanisme. L'injection précoce d'huile dans les échantillons, précédant la circulation de fluide aqueux provoque l'inhibition de la PSC par un coating des grains, résultant en la préservation de la porosité. Les résultats de cette étude montrent l'importance de la chimie du fluide de circulation et du timing de mise en place des hydrocarbures dans la préservation de la porosité précoce à grande profondeur / The preservation of good petrophysical properties (high porosity / high permeability) at great depth in carbonate rocks may lead to the existence of a deeply buried reservoir (DBR), a target of interest for the oil industry. However, chemo-mechanical processes involved in the burial diagenesis of carbonate petroleum reservoirs are still poorly understood or restrained and few experimental results exists in this domain. To better understand these processes and explain how porosity and permeability can be preserved at the great depth of DBR (burial > 4000m), we developed an innovative experimental device and an associated protocol. This device allows both the simulation of high pressure/stresses/temperature conditions (80°C, 60 MPa of confining pressure and differential stress up to 40 MPa) of DBR and the circulation of different fluids in rock samples. Through a multidisciplinary approach we tested core samples of a cemented bioclastic limestone (Massangis limestone) and we analyzed creep deformations, chemistry of pore fluids, petrographical and petrophysical properties of samples. It has been demonstrated that there exists an important relationship between the mechanical stress affecting the rock, the thermodynamic of water/rock interactions and the evolution of the petrophysical properties. The main process responsible for creep deformation of carbonated rocks during burial has been determined to be Intergranular Pressure Solution (IPS) resulting in Pressure Solution Creep (PSC) which is the main process implied in the porosity reduction of a carbonate rock during deep burial. Different flow conditions (no-flow and flow-through) and chemical compositions (natural meteoric water, adjunction of phosphate ions, brine) were considered. The effects of hydrocarbon and of their timing of set-up have also been investigated. It has been discovered from our study that, in presence of meteoric fluid, PSC happens at the micritic scale, and results in the blocking of microporosity between micrites crystals due to the precipitation of calcite on free pore walls of micrites. The preservation of macropores allows the preservation of permeability. The adjunction of phosphate ions in the circulating fluid results in the inhibition of PSC while the increase of salinity by addition of NaCl leads to its acceleration. An early injection of oil prior to water circulation causes the inhibition of PSC by the coating of the grains, leading to the preservation of porosity. The dataset obtained from this study show the importance of fluid chemistry and of the timing of oil charging in a reservoir in the preservation of early porosity at great depth

La surface terrestre est affectée par de nombreux processus locaux tels que des événements volcaniques, des glissements de terrain ou des tremblements de terre. Parallèlement à ces processus naturels, les activités anthropiques, y compris l’extraction et le stockage des ressources profondes (par exemple, les minéraux ou les hydrocarbures) façonnent la Terre à différentes échelles spatiales et temporelles. Ces mécanismes produisent une déformation du sol qui peut être détectée par divers instruments et techniques géodésiques tel que le GNSS, l’InSAR, les inclinomètres. Le but de cette thèse est de développer un outil numérique permettant l’inversion conjointe de multiples données géodésiques associées à la déformation de la plaque ou au changement de contrainte volumique en profondeur. Quatre types d’applications sont ciblés: la déformation intersismiques des plaques, la déformation des volcans, l’exploitation minière profonde et l’extraction de pétrole et de gaz. Différentes complexités du modèle inverse ont été considérées: le niveau I considère un seul type de données géodésiques avec un processus indépendant du temps. Une application est réalisée avec l’inversion des données GPS à travers le sud de la Californie pour déterminer les variations latérales de la rigidité lithosphérique (Furst et al., 2017). Le niveau II représente également un seul type de données géodésiques mais avec un processus dépendant du temps. La détermination conjointe de l’historique des changements de contrainte et des paramètres de dérive d’un réseau d’inclinomètres est étudiée à l’aide d’un exemple synthétique (Furst et al., soumis). Le niveau III considère différents types de données géodésiques et un processus dépendant du temps. Un réseau fictif combinant des données GNSS, InSAR, inclinométriques et de nivellement est défini pour calculer le changement de volume dépendant du temps d’une source profonde de déformation. Une méthodologie pour implémenter ces différents niveaux de complexité est développée dans un seul logiciel. Parce que le problème inverse peut être mal posé, la minimisation de la fonctionnelle peut produire plusieurs minima. Par conséquent, un algorithme d’optimisation global est utilisé (Mohammadi and Saïac, 2003). Le problème direct est traité en utilisant un ensemble de modèles élastiques numériques et analytiques permettant de modéliser les processus de déformation en profondeur. Grâce à ces développements numériques, des avancées concernant les problèmes inverses en géodésie devraient être possibles telle que l’inversion jointe de différents types de données géodésiques acquises lors de la surveillance des volcans. Dans cette perspective, la possibilité de déterminer par inversion les paramètres de dérive des inclinomètres permettrait une détermination précise des sources de déformation profondes. En outre, la méthodologie développée peut être utilisée pour une surveillance précise de la déformation des réservoirs de pétrole et de gaz. / The Earth’s surface is affected by numerous local processes like volcanic events, landslides or earthquakes. Along with these natural processes, anthropogenic activities including extraction and storage of deep resources (e.g. minerals, hydrocarbons) shape the Earth at different space and time scales. These mechanisms produce ground deformation that can be detected by various geodetic instruments like GNSS, InSAR, tiltmeters, for example. The purpose of the thesis is to develop a numerical tool to provide the joint inversion of multiple geodetic data associated to plate deformation or volume strain change at depth. Four kinds of applications are targeted: interseismic plate deformation, volcano deformation, deep mining, and oil & gas extraction. Different inverse model complexities were considered: the I-level considers a single type of geodetic data with a time independent process. An application is made with inverting GPS data across southern California to determine the lateral variations of lithospheric rigidity (Furst et al., 2017). The II-level also accounts for a single type of geodetic data but with a time-dependent process. The joint determination of strain change history and the drift parameters of a tiltmeter network is studied through a synthetic example (Furst et al., submitted). The III-level considers different types of geodetic data and a timedependent process. A fictitious network made by GNSS, InSAR, tiltmeters and levelling surveys is defined to compute the time dependent volume change of a deep source of strain. We develop a methodology to implement these different levels of complexity in a single software. Because the inverse problem is possibly ill-posed, the functional to minimize may display several minima. Therefore, a global optimization algorithm is used (Mohammadi and Saïac, 2003). The forward part of the problem is treated by using a collection of numerical and analytical elastic models allowing to model the deformation processes at depth. Thanks to these numerical developments, new advances for inverse geodetic problems should be possible like the joint inversion of various types of geodetic data acquired for volcano monitoring. In this perspective, the possibility to determine by inverse problem the tiltmeter drift parameters should allow for a precise determination of deep strain sources. Also, the developed methodology can be used for an accurate monitoring of oil & gas reservoir deformation.

Os reservatórios de água são sistemas artificiais rasos destinados à múltiplos usos. Estes usos associados as atividades desenvolvidas na bacia hidrográfica acarretam impactos nos corpos d\'água, principalmente nos sedimentos, os quais representam um depósito e também uma fonte de contaminantes sobre determinadas condições ambientais. O tipo de construção dos reservatórios é bastante relevante no contexto de poluição e contaminação. Teoricamente os reservatórios construídos em cascata tendem a apresentar uma melhora na qualidade das águas e sedimentos ao longo da construção, pois o reservatório acima retém parte dos poluentes e contaminantes que entrariam no reservatório subsequente. Para avaliar a qualidade dos seis reservatórios construídos em cascata no rio Tietê (SP), foram realizadas quatro coletas (outubro/99, fevereiro/00, maio/00 e julho/00) nas quais foram amostradas água e sedimento para realização de análises físicas, química , biológica e ecotoxicológica, em 15 pontos deste sistema. Os resultados em geral demonstraram uma melhoria nas condições físicas e químicas da água, sedimento e da toxicidade (% de mortalidade) nos últimos reservatórios (Nova Avanhandava e Três Irmãos), sendo que os rios Piracicaba e Tietê apresentaram as piores condições ambientais. A toxicidade variou com o período de coleta, sendo que as maiores porcentagens de mortalidade ocorreram em outubro/99 e as menores em maio/00. As análises histológicas realizadas com organismos expostos aos sedimentos coletados em fevereiro, confirmaram alterações branquiais de primeiro grau em sete dias de exposição. As análises químicas das águas extraídas dos bioensaios em maio/00 também demonstraram a presença de nutrientes e metais em concentrações elevadas, confirmando então a importância dos sedimentos como liberadores de poluentes para a coluna de água, prejudicando os organismos de coluna de água. / Water reservoirs are shallow artificial systems which can be constructed for many purposes. The use of these reservoirs and the different activities developed in the hydrographic basin, can result in alterations in these border water, mainly in the sediments, which represent a storage and a contaminant source under specific ambient conditions. The position of the reservoir along the river is very significant in relation to pollution and contamination. Cascade reservoirs are prone to raise the water and sediment quality downstream, because contaminants and pollution are retained in the upstream reservoirs. In order to assess the water and sediment quality in six Tietê river cascade reservoirs, we realized chemical, physical, biological and ecotoxicological analysis in 15 locations. Samples were collected in October/1999, February, May and July/2000. The overall results showed that water and sediments physical and chemical conditions, as well as the toxicity (% mortality), were improved in direction to the last reservoirs (Nova Avanhandava e Três Irmãos). Piracicaba and Tietê rivers presented the worst ambient conditions. The toxicity presented seasonal variation, in the manner that higher mortality percentage occurred in October and the lower in May. Hystological analysis of text organism exposed to sediments collected in February showed branchial alterations after seven days. Chemical analysis of the water used in the bioassays showed high metal and nutrients concentrations in May, suggesting the importance of these sediments, since they are able to release pollutants to the water column.

O Estado de São Paulo, devido a seu alto grau de industrialização, grande densidade demográfica e técnicas de produção agrícola, tem grande arte de seus mananciais impactados. As avaliações da qualidade da água são de vital importância para o manejo adequado e recuperação desses sistemas, todavia os programas atuais de monitoramento são incompletos no sentido de não permitirem uma avaliação global dos efeitos dos contaminantes sobre a biota aquática. Esses programas enfocam preferencialmente a coluna d\'água, porém é o sedimento o compartimento preferencial de armazenamento e transformações de contaminantes e nutrientes. Para que, associados a outros estudos e métodos de análise, possam ser desenvolvidas as bases metodológicas para a definição de critérios de qualidade de sedimentos, foram realizados bioensaios crônicos com amostras de sedimento de seis represas do sistema do Rio Tietê (Pedro Beicht, Rasgão, Billings, Barra Bonita, Promissão e Bariri), nos períodos de outubro e novembro de 2000 e de 2001, bem como testes para a determinação da faixa de sensibilidade de Chironomus xanthus às substâncias dicromato de potássio - K2Cr2O7 (4,82 ~ 9,41 mg/L), sulfato de zinco - ZnSO4 (1,46 ~ 13,47 mg/L), cloreto de cádmio - CdCl2 (0,34 ~ 1,11 mg/L), sulfato de cobre - CuSO4(1,13 ~ 1,77 mg/L), cloreto de potássio - KCl (2,91 ~ 3,77 g/L) e atrazina (1,43 ~ 2,72 mg/L). Os resultados dos testes com amostras ambientais indicaram maior toxicidade nos reservatórios de Rasgão e Billings e em menor grau em Barra Bonita e Bariri. / The são Paulo State, due to its high levels of industrialization, great demographic density and agricultural techniques, has most of its water resources compromised. The water quality assessments are fundamental to the appropriate management and recover of these systems, however the existing monitoring programs are incomplete and do not allow the assessment of all the effects that the contaminants can carry out in the aquatic biota. The main approach of these programs is the water column, but the sediment is the preferential compartment of contaminants and nutrient storing and alteration. Associated to other studies and analyses, this work intends to help to develop the methodological basis to define the sediment quality criteria by doing chronic bioassays with sediment samples of six reservoir of the Tietê river system (Pedro Beicht, Rasgão, Billings, Barra Bonita, Promissão e Bariri) , as well as determining the Chironomus xanthus sensibility to the substances K2Cr207 (4,82 ~ 9,41 mg/L), ZnSO4 (1,46 ~ 13,47 mg/L), CdCl2 (0,34 ~ 1,11 mg/L), CuSO4 (1,13 ~ 1,77 mg/L), KCl (2,91 ~ 3,77 g/L) and atrazine (1,43 ~ 2,72 mg/L). The environmental bioassays showed that the highest toxicity was found in Rasgão and Billings reservoirs while Barra Bonita and Bariri showed minor levels of toxic effects.

O entendimento da comunidade fitoplanctônica em sistemas instáveis, como por exemplo reservatórios, necessita conhecimento de escalas de variabilidade. Com base nisso, um estudo sobre a heterogeneidade espacial e variabilidade temporal de dois reservatórios com diferentes graus de trofia, no Estado de São Paulo foi realizado em 20 estações no reservatório de Salto Grande e em 19 no reservatório do Lobo, em 3 dias consecutivos, em quatro períodos: outubro de 1999, janeiro, abril e junho e julho de 2000. Para tanto foram determinadas as concentrações de nutrientes totais e dissolvidos, material em suspensão, carbono inorgânico, clorofila a, biomassa, densidade, composição e produtividade primária da comunidade fitoplanctônica e os perfis de oxigênio dissolvido, temperatura, pH e condutividade. Os dois reservatórios tiveram estruturas espaciais semelhantes com a formação de três zonas distintas. A zona de rio, misturada, com menor penetração de luz e maior concentração de nutrientes, a zona de transição, e a zona lacustre, mais estratificada, com maior penetração de luz e menor concentração de nutrientes. Apesar dessa compartimentalização a heterogeneidade espacial no reservatório de Salto Grande foi maior que no reservatório do Lobo, sobretudo em função do gradiente longitudinal de nutrientes e luz. A variabilidade diária (3 dias) nos dois reservatórios não foi significativa na determinação da comunidade fitoplanctônica. A escala de variabilidade sazonal, nos dois reservatórios, foi determinada, principalmente pela variação nos padrões de estratificação e mistura sendo, assim, determinante na composição da comunidade fitoplanctônica. Essa influência foi mais evidente no reservatório do Lobo. A variação temporal e heterogeneidade espacial das mais abundantes espécies e grupos taxonômicos da comunidade fitoplanctônica, (Microcystis aeruginosa, Anabaena crassa e Anabaena circinalis em Salto Grande e Aphanocapsa delicatissima, Coelastrum reticulatum e Aulacoseira granulata no Lobo) nos dois reservatórios foram determinados pelos complexos processos de estratificação e mistura e da disponibilidade de luz. Os resultados obtidos são importantes para o entendimento da variabilidade ambiental de reservatórios tropicais e no planejamento de amostragens que visem o gerenciamento desses sistemas. / The understanding of the phytoplanktonic community in unstable systems, like reservoirs, needs the knowledge of variability scales. Based on it, a study of the spatial heterogeneity and temporal variability in two reservoirs with different trophic levels in São Paulo State was performed in 20 stations of the Salto Grande reservoir and in 19 of Lobo reservoir, for 3 consecutive days, in four periods: October 1999, January, April, June, and July 2000. Total and dissolved nutrients, suspended material, inorganic carbon, chlorophyll, biomass, density, and phytoplanktonic community composition were determined. The two reservoirs showed similarities in their spatial structure with the formation of three distinct zones. The riverine zone, wish was mixed, showing less light penetration and higher nutrients concentration; the transistion zone and the lacustrine zone, which was more stratified, with higher light penetration and lower nutrients concentration. Despite this compartimentalization, the spatial heterogeneity in Salto Grande reservoir was larger than in Lobo reservoir, mainly in function of the longitudinal gradient of nutrients and light. The daily variability (3 days) in the two reservoirs was not significant in the phytoplanktonic community determination. The seasonal variability scale in the two reservoirs was determined, mainly due to the stratification and mixing variation patterns and was essential in the phytoplanktonic community composition. This influence was more evident in the Lobo reservoir. The temporal variation and spatial heterogeneity of the dominants species and taxonomic groups from the phytoplanktonic community, (Microcystis aeruginosa, Anabaena circinalis and Anabaena crassa in Salto Grande reservoir and Aphanocapsa delicatissima, Coelastrum reticulatum and Aulacoseira granulata in the Lobo) were determined by complex processes of stratification, mixing, and light availability in the two reservoirs. The results obtained are important for the understanding of the environmental variability of tropical reservoirs and for the planning of sampling aim at the management of these systems.