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Anthropisation des processus hydrologiques autour de l’oued Merguellil, Tunisie centrale : caractérisation des formes d’évolution et quantification des flux / Anthropisation of hydrological processes around the Wadi Merguellil in central Tunisia : characterization of evolution forms and flux quantificationJerbi, Hamza 28 November 2018 (has links)
Le bassin du Merguellil, en Tunisie centrale, fournit un exemple illustratif des processus hydrologiques profondément modifiés par l’action humaine. L’oued Merguellil, le principal cours d’eau du bassin, a vécu une évolution socio-hydrologique extrêmement marquée. En effet, son état actuel est l’héritage d’une longue histoire d’interactions entre l’homme et son milieu. Il est actuellement intermittent sur la majeure partie de son cours, or les dires des riverains et les documents anciens révèlent qu’il n’en était pas ainsi au début du siècle dernier. Le recours aux informations anciennes issues des documents d’archives a montré que l’oued Merguellil était autrefois soutenu principalement par le déversement de la nappe captive de Bouhefna. Durant les années 1974-1975 et afin de transférer les eaux souterraines du bassin du Merguellil vers les régions côtières, une stratégie politique a été mise en place pour rabattre le niveau de la nappe de Bouhefna de manière à pouvoir réduire ‘’les pertes’’ par évaporation dans l’oued Merguellil et minimiser l’écoulement souterrain vers la nappe voisine de Haffouz d’intérêt hydrogéologique moins important. Comme prévu, cela a induit une inversion du gradient hydraulique oued-nappe inférant le tarissement des sources de déversement, la vidange de la nappe d’accompagnement et la disparition du débit de base de l’oued Merguellil à partir de 1976-1978. La modélisation hydrodynamique établie dans cette thèse suggère que le flux souterrain qui transitait vers l’oued par drainance verticale avant l’inversion du gradient hydraulique est de l’ordre de 9 hm3. Désormais c’est les crues de l’oued qui alimentent la nappe alluviale et les nappes superficielles. Le flux moyen infiltré lors de la propagation des crues est estimé à 17 hm3 dans la section de l’oued entre la station de Haffouz et barrage El Haouareb pour l’année 2013-2014.Toutefois, le schéma de gestion de la nappe de Bouhefna a été basé exclusivement sur des considérations hydrodynamiques sans tenir compte de l’évolution des usages. En effet, la disparition de l’étiage de l’oued a contraint les riverains à abandonner les canaux d’irrigation traditionnels et à opter pour l’installation de motopompes et la mise en place des forages profonds. Cette rétroaction face au changement de régime d’écoulement de l’oued a contribué à perturber davantage l’équilibre hydrologique. Cela s’est traduit par une exploitation excessive des eaux souterraines avec une baisse actuelle observée de la piézométrie supérieure à 1m/an et une inversion du gradient entre la nappe de Bouhefna et la nappe de Haffouz. La modélisation hydrodynamique suggère que les flux moyens échangés par drainance verticale sont passés de 8 hm3 en 1970 à 2 hm3 en 2015. Dans le sens inverse, les flux transitant depuis la nappe de Haffouz vers la nappe de Bouhefna sont évolués de 1 hm3 en 1970 à 6 hm3 en 2015, imposant ainsi un risque de salinité à long terme.Le transfert des eaux de Bouhefna vers les régions côtières, même s’il est largement contesté par les populations locales, n’a jamais été mis en avant comme facteur explicatif des évolutions hydrologiques vécues localement, les travaux de cette thèse permettent pourtant de montrer à quel point ce transfert d’eau a influencé le régime hydrologique de l’oued. Toutefois, en n’omettant pas leurs propres responsabilités dans ces dynamiques, les agriculteurs font preuve de lucidité. En effet, le modèle hydrodynamique suggère que la part cumulée des volumes en eau souterraine mobilisés par ces derniers après la disparition de l’étiage de l’oued est comparable à celle destinée à l’eau potable. Les résultats de cette thèse rejoignent les recherches en socio-hydrologie qui appellent à intégrer les aspects sociaux dans les schémas de gestion pour garantir un développement durable des ressources en eaux. / The Merguellil basin in central Tunisia provides an illustrative example of hydrological processes profoundly modified by human action. The Wadi Merguellil, the main river of the basin, has experienced an extremely marked socio-hydrological evolution. Its current state is the legacy of a long history of interactions between man and his environment. Truly, it is currently intermittent over most of its course, but the statements of farmers and archival records reveal that this was not the case at the beginning of the last century. The use of ancient information from archival documents has shown that the Wadi Merguellil was supported mainly by the overflow of the confined aquifer of Bouhefna. During the years 1974-1975 and in order to transfer groundwater resources from the Merguellil basin to the coastal regions, a management plan was put in place. The aim of this plan was to reduce the level of the Bouhefna aquifer so as to reduce '' losses '' by evaporation in the Wadi Merguellil and minimize the groundwater flow towards the nearby Haffouz aquifer. As expected, this strategy led to a reversal of the hydraulic gradient inferring the drying up of the overflow springs, the emptying of the alluvial aquifer and the disappearance of the Wadi Merguellil baseflow during the period 1976-1978. The hydrodynamic model established in this thesis suggests that the averaged groundwater flow that was feeding the Wadi before the hydraulic gradient reversal is around 9 hm3. Currently, it is rather the floods of the Wadi that feed the alluvial aquifer and the shallow aquifers. The average flow infiltrated during the propagation of flood events is estimated at 17 hm3 in the section of the wadi between the Haffouz station and El Haouareb dam for the year 2013-2014.Though, the exploitation management plan of the Bouhefna aquifer was based exclusively on hydrodynamic considerations without taking into account the evolution of hydro-agricultural practices. Indeed, the disappearance of the baseflow of the Wadi Merguellil has forced farmers to abandon traditional irrigation canals and opt for the installation of motor pumps and the establishment of deep wells. This feedback on the change in the Wadi flow regime has further disrupted the hydrological balance. This resulted in an excessive exploitation of the groundwater with an observed current decrease of the piezometry higher than 1m/year and a reversal of the hydraulic gradient between the Bouhefna aquifer and the Haffouz aquifer. The hydrodynamic model suggests that the average flow exchanged by vertical drainage has decreased from 8 hm3 in 1970 to 2 hm3 in 2015. In the opposite direction, the average flow transiting from the Haffouz aquifer to the Bouhefna aquifer has increased from 1 hm3 in 1970 to 6 hm3 in 2015, imposing a risk of salinity in the long term.The transfer of water from Bouhefna to the coastal regions, even though it is widely disputed by the local populations, has never been put forward as a factor explaining the hydrological evolution experienced locally. The work of this thesis allows to show how much this transfer of water has influenced the hydrological regime of the wadi. However, by not omitting their own responsibilities in these dynamics, farmers are lucid. Indeed, the hydrodynamic model suggests that the cumulative part of groundwater volumes mobilized by the latter after the disappearance of the Wadi baseflow is comparable to that for drinking water. The results of this thesis are in line with research in socio-hydrology that calls for integrating social aspects into management plans to ensure sustainable development of water resources.
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Kartläggning av riskområden för inducerad infiltration i grundvattentäkter / Mapping of Risk Areas for Induced Infiltration into GroundwaterSundström, Martin January 2019 (has links)
Uttag av grundvatten är viktigt då det förser nästan hälften av befolkningen i Sverige med dricksvatten. Vid uttag som leder till avsänkning av grundvattennivån kan en inträngning av organiskt material uppstå om det finns ett intilliggande ytvattendrag, ett fenomen som kallas inducerad infiltration. Nackdelarna vid den här typen av läckage från ytvatten är att det är svårt att kontrollerna och att det organiska materialet förbrukar syre, vilket i sin tur kan leda till att järn och mangan löses ut i grundvattenmagasinen. Omformningen från ytvatten till grundvatten går för fort och vattnet renas sämre med risken att också dricksvattenkvalitén försämras. I den här rapporten gjordes en kartläggning som markerade riskområden för inducerad infiltration i Sverige. Dessa områden visade sig finnas jämnt utspridda över hela landet. En närmare undersökning gjordes av mätserier från Gävleåsen och Vanåsen, två åsar som huserar grundvattentäkter. Vanåsen representerades endast av en mycket liten markering i kartläggningen men där visade sig en tydlig ökning av organisk halt och stora problem, medan Gävleåsen var mer synlig i kartan utan att ge något entydigt resultat av ökande halter. Slutsatsen är att där uppförande av vattentäkter planeras måste noggranna analyser utföras för att få en helhetsbild av området, intilliggande ytvattendrag och grundvattenflödets riktningar. / The use of groundwater is important as it supplies almost half of the population in Sweden with drinking water. In the case of withdrawals that lead to a lowering of the groundwater level, an intrusion of organic material might occur if there is an adjacent surface watercourse, a phenomenon known as induced infiltration. The disadvantages of this type of leakage from surface water is that it is difficult to control and that the organic material consumes oxygen, which in turn can lead to iron and manganese being dissolved in the groundwater reservoirs. The transformation from surface water to groundwater goes too fast and the water isn’t filtered good enough with the risk that the quality of the drinking water also deteriorates. In this report, a mapping study was made to mark risk areas for induced infiltration in Sweden. These areas proved to be evenly distributed throughout the country. A closer examination was made of series of measurements from Gävleåsen and Vanåsen, two ridges with groundwater sewers. Vanåsen was only represented by a very small mark in the mapping, but there was a clear increase in organic content and major problems, while Gävleåsen was clearly visible in the map without giving any univocal result of increasing concentrations. The conclusion is that where construction of water sources is planned, detailed analyzes must be carried out in order to obtain an overall picture of the area, adjacent surface watercourses and the directions of the groundwater flow.
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Approches de modélisation pour la partition ruissellement-infiltration à différentes échelles spatiales et temporelles : cas de la parcelle de Thies (Sénégal) et du bassin versant de Houay Pano (Laos) / Modelling approaches for runoff-infiltration partitioning at various space and time scales : Case study of Thies (Senegal) and Houay Pano (Laos)Patin, Jérémy 06 June 2011 (has links)
Ce travail de thèse s’inscrit dans le cadre de la modélisation distribuée de la partition ruissellement-infiltration en milieu naturel. Notre démarche consiste à étudier la réponse de systèmes naturels complexes à partir de mesures locales, d’expérimentations numériques et de modèles distribuées. Les expériences de la parcelle de Thiès (40m2), au Sénégal, montrent que les hétérogénéités de rugosités mettent en défaut les lois de friction classiques (Manning, Darcy- Weisbach) des modèles de ruissellement qui sous estiment les hautes vitesses. Deux lois qui prennent en compte la hauteur de submersion de la rugosité de manière physique ou empirique sont testées. Dans le bassin versant de Houay Pano, les données obtenues sous pluie simulées, sur des placettes de 1m2, permettent de mettre en évidence l’effet des hétérogénéités, en particulier en terme d’encroutement du sol et de végétation, sur le ruissellement intégré spatialement. L’infiltration moyenne apparait comme dépendante de l’intensité de pluie et l’effet d’une distribution statistique d’infiltrabilité sur le transitoire et le permanent d’infiltration est étudié. La distribution exponentielle d’infiltrabilité semble la plus adaptée, elle est utilisée pour analyser la variabilité spatiale et temporelle de la production de ruissellement dans le bassin versant sous pluie naturelle. Enfin, ce modèle exponentiel, simple mais pertinent à l’échelle du mètre, est implémenté pour représenter un pixel de base dans un modèle de ruissellement-infiltration à l’échelle d’un sous bassin versant de 0.5 ha et différents scénarios de modélisation sont envisagés / This work deals with distributed modeling of runoff-infiltration processes in a natural environment. The response of complex natural systems is studied from local measurements, numerical investigations and distributed models. Experiments held in Thies, Senegal, on a 40m2 plot show that the heterogeneity of the surface put in the wrong classical friction laws (Manning, Darcy-Weisbach) of runoff models, because they underestimate high velocities. Two laws, taking physically or empirically into account the submersion of rugosity, are tested. In the Houay Pano catchment, we highlight from simulated rainfall experiments on 1m2 plots the effects of heterogeneities, mainly due to soil crusting and vegetation, on the spatially integrated runoff. We observed that the mean infiltration rate is dependent of the rainfall intensity and studied the effects of a statistical distribution of infiltrabilities on permanent and non-permanent infiltration. The exponential distribution of infiltrabilities appeared to be the best suited distribution. It is used to analyze spatial and temporal variability of runoff production in the catchment under natural rainfall, in order to obtain a per land use characterization of infiltration. Eventually, this simple but accurate model at the meter scale is implemented as a base pixel into a runoff-infiltration model at the sub-catchment scale (0.5 ha)
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Simulation du ruissellement d'eau de pluie sur des surfaces agricoles / Rain water overland flow on agricultural fields simulationDelestre, Olivier 13 July 2010 (has links)
L’objectif de ce travail est le développement d’un modèle et d’une méthode numérique adaptés à la simulation duruissellement d’eau de pluie sur des surfaces agricoles. Pour cela, nous utilisons un système d’équations aux dérivéespartielles pour les eaux peu profondes : le système de Saint Venant. La pluie et l’infiltration y sont pris en compte parl’ajout de termes source et le couplage avec un modèle d’infiltration. Le système étant hyperbolique et conservatifnous choisissons d’utiliser un schéma aux volumes finis avec reconstruction hydrostatique. Avec cette reconstructionnous obtenons un schéma permettant de traiter les équilibres stationnaires et les interfaces sec/mouillé dues auxévénements pluvieux. Tout d’abord, nous effectuons une comparaison systématique de différents flux numériques,de différentes reconstructions d’ordre deux (MUSCL et ENO modifiées) et de différentes méthodes de traitementdes frottements sur des solutions analytiques unidimensionnelles. Ces comparaisons nous permettent de choisirune méthode numérique adaptée à la simulation du ruissellement qui en outre capture les phénomènes de typeroll-waves. Ensuite nous nous intéressons au traitement de la pluie et de l’infiltration à l’aide du modèle de Green-Ampt. Cette méthode généralisée en dimension deux est validée sur des résultats expérimentaux obtenus à l’INRAd’Orléans et à l’IRD. La méthode numérique choisie et validée a été implémentée dans FullSWOF_2D un logiciellibre écrit en C++ pour la simulation de ruissellement d’eau de pluie sur des surfaces agricoles. / In this work, we aim at developping both a model and a numerical method adapted to the simulation of rainfallrunoff on agricultural fields. The model used is a system of partial differential equations for shallow water flows :namely the system of Saint Venant. Rain and infiltration are treated as source terms and with a coupled model ofinfiltration. Because of the hyperbolicity and conservativity properties, we are using a finite volume scheme with thehydrostatic reconstruction. This reconstruction allows us to deal with stationary equilibria and wet/dry transitionsdu to rainfall events. First, a systematic comparison on analytic solutions is achieved between various numericalfluxes, two second order reconstructions (a MUSCL and a modified ENO reconstructions) and different numericaltreatment of the friction term. This allows us to choose a numerical method adapted to runoff simulation. Moreoverit is able to catch roll waves phenomenons. Then we are interested in the rain and infiltration treatment. Infiltrationis modeled thanks to the Green Ampt model. This method is thereafter generalized to two dimensions and validatedon experimental results obtained by the INRA of Orléans and the IRD. The chosen numerical method has beenimplemented in an C++ open-source software for rainfall runoff on agricultural fields simulations : FullSWOF_2D.
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Modellierung der Interaktion zwischen Grundwasser und KanalisationKarpf, Christian 30 November 2012 (has links) (PDF)
Der Austausch zwischen Grundwasser und Kanalnetz kann in die Prozesse der Grundwasserinfiltration in Kanalnetze und der Abwasserexfiltration aus Kanalnetzen unterteilt werden. Generell entstehen durch die In- und Exfiltration (I/E) erhöhte Kosten der Abwasserentsorgung und eine Belastung für Boden, Grundwasser und Oberflächenwasser. Für Einschätzungen zur Dynamik und Quantität der In- und Exfiltration ist die Nutzung von Modellen sinnvoll, da zahlreiche Einflussfaktoren in die Betrachtungen einfließen können und dadurch eine komplexe Erfassung der Prozessmechanismen ermöglicht wird.
Im Rahmen der vorliegenden Arbeit wurden physikalisch basierte Modelle zur Abbildung der In- und Exfiltrationsprozesse hinsichtlich erforderlicher Parameter und Randbedingungen analysiert und angewandt. Anhand detaillierter 3D-Modelle, kleintechnischer Versuche, Datenanalysen und statistischer Verfahren erfolgte die Modifizierung und Entwicklung von I/E-Modellen sowie die Parameteridentifikation zur Abbildung der In- und Exfiltration. Des Weiteren wurden die entwickelten Modellansätze mit einem hydrodynamischen Kanalnetzmodell verknüpft und großräumige Langzeitsimulationen durchgeführt.
Die Untersuchungen zeigen bezüglich der Infiltration von Grundwasser in das Kanalnetz, dass eine physikalisch basierte Prozessmodellierung einer Abstraktion bedarf, um die 3-Dimensionalität des Prozesses in einem 1D-Modell wieder zu geben und dadurch die Anbindung an ein Kanalnetzmodell zu ermöglichen. Anhand von Simulationsrechnungen wurde festgestellt, dass die quantitative Betrachtung der Infiltration auf Einzugsgebietsebene keine hydrodynamische Modellierung erfordert. Signifikante quantitative Änderungen der Grundwasserinfiltration aufgrund der Wasserstandsschwankungen in den Kanälen sind nur lokal oder temporär von Bedeutung. Die Grundwasserinfiltration kann jedoch deutliche Auswirkungen auf die Ergebnisse der hydrodynamischen Simulation haben. Anhand von Datenanalysen im Einzugsgebiet Dresden konnte des Weiteren ein signifikanter Zusammenhang zwischen Infiltrationsparametern und Kanalzustand ermittelt werden.
Der Exfiltrationsprozess kann durch ein 1D-Modell gut abgebildet werden, wobei der Prozess der Bodenkolmation anhand eines zeit- und potenzialabhängigen Modells implementiert werden kann. Ferner konnte durch die Verknüpfung mit Infiltrationsanalysen eine Ableitung der Schadensfläche erfolgen, die als Parameter in die Exfiltrationsmodellierung eingeht. Die hydrodynamischen Berechnungen zeigen, dass für die Exfiltrationsmodellierung eine möglichst exakte Berechnung der Wasserstände in Kanalnetzen essentiell ist. / The water exchange between groundwater and sewer system can be characterized by the processes of groundwater infiltration and sewerage exfiltration. Infiltration and exfiltration (I/E) cause an increase of the costs of sewerage management and a deterioration of soil, groundwater and the receiving surface water. In order to assess the dynamics and quantities of I/E, model applications can be used in order to include influencing factors and to afford a complex consideration of the process mechanisms.
Within this work I/E-approaches were analyzed and modified in order to assess parameters and boundary conditions. The parameter identification and model development was realised according to the application of a detailed 3D-model, the realization of experiments, data analyses and the application of statistical methods. Furthermore the developed and modified approaches were coupled with a hydrodynamic sewer network model and long term simulations were performed.
It was found that a physical based description of the infiltration process requires the implementation of the 3-dimensionality of the process. A hydrodynamic modelling of the sewer flow processes is not necessary to quantify infiltration rates on catchment scale, but the results of hydrodynamic modelling can be influenced significantly by groundwater infiltration. Furthermore data analyses of data of Dresden show a significant relationship between infiltration parameters and the condition class of the sewer pipes.
The exfiltration process can be described by a 1D-model, whereat the processes of soil clogging are simulated by a time and potential based approach. Using the infiltration analyses it was possible to calculate the leak area, which is an important parameter of the exfiltration modelling. Hydrodynamic simulations show that the exfiltration modelling requires an accurate calculation of water levels in sewers.
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Avaliação de elementos de infiltração de águas pluviais na zona norte da cidade de Goiânia / Evaluation of evidence of infiltration of rainwater in the northern city of GoianiaCARVALHO, Eufrosina Terezinha Leão 29 August 2009 (has links)
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Previous issue date: 2009-08-29 / The development of the urban environment results in an expansion of impervious ground surfaces that greatly affects the hydrological cycle in the cities. The objective of this
research is to evaluate infiltration structures for the control of excess drainage at the origin of runoff. These structures are constructed with the purpose of minimizing the impact of
impervious surfaces to the urban environment. An experimental field was established consisting of several infiltration structures, such as small-diameter pilot wells and real scale wells. The real scale wells used perforated concrete pipe casing and brick lining. Falling-head infiltration tests were carried out during 15 months, encompassing the dry and rainy seasons. The infiltration tests were undertaken with initial conditions that correspond to the natural water content at the time of testing. Additional tests were undertaken with previously flooded conditions, reproducing several consecutive rainy days. The monitoring of pilot wells along with real scale wells allowed the evaluation of project parameters obtained from pilot wells. The values of average infiltration rate of different infiltration wells were compared and the performance of the several structures was compared. Laboratory test were carried out for the determination of the hydraulic parameters of the ground profile, including the saturated hydraulic conductivity the soil-water characteristic curve. A numerical model for the simulation of infiltration wells was implemented using the software FlexPDE. Special boundary conditions were developed that take into account the transient relationship between the varying hydraulic head at the well walls and the total volume infiltrated during a test. The numerical simulations contributed for a better understanding of the infiltration mechanism, the influence of the hydraulic conductivity to the infiltration rate, and the determination of the wetting front and pore-water pressures during infiltration. A design criterion for infiltration wells was proposed using daily compensation, considering the daily water balance during 25 years, and the precipitation historical series of the site. The proposed design criterion makes possible the selection of the group of infiltration structures that meet the project goals. The design criterion also allowed the evaluation of the theoretical performance of wells designed using two conventional criteria / A expansão do ambiente urbano causa o aumento das superfícies impermeabilizadas, alterando o ciclo hidrológico nas cidades. Esta pesquisa buscou avaliar estruturas de
infiltração para o controle de fluxos superficiais na fonte, construídas com a finalidade de minimizar os impactos da impermeabilização nas cidades. Foi estabelecido um campo
experimental composto por diversas estruturas de infiltração, incluindo poços piloto de pequeno diâmetro e poços em escala real. Os poços em escala real foram revestidos em tubo de concreto perfurado e em tijolo maciço assentado em crivo. Ensaios de infiltração com carga variável foram realizados durante 15 meses, abrangendo as estações seca e chuvosa. Os ensaios de infiltração foram realizados em condição inicial de umidade natural e em condição pré-inundada, procurando reproduzir vários dias consecutivos de chuva. O monitoramento dos poços piloto, juntamente com estruturas de infiltração em escala real, permitiu a avaliação dos
parâmetros de projetos obtidos a partir dos poços piloto. Os valores de taxa de infiltração média foram comparados entre os diferentes elementos de infiltração e permitiram comparar o
desempenho das estruturas. Foram realizados ensaios de laboratório para obtenção de parâmetros hidráulicos do perfil de solo do campo experimental. Dentre as propriedades
avaliadas destacam-se a permeabilidade do solo saturado e a curva característica. Um modelo numérico foi implementado utilizando o programa FlexPDE. Foram desenvolvidas condições de fronteira especiais que consideram a dependência transiente entre a carga hidráulica nas paredes do poço e o volume total infiltrado durante o ensaio. A simulação numérica permitiu o melhor entendimento do mecanismo de infiltração, a influência da permeabilidade na taxa de infiltração e a determinação da frente de saturação e da distribuição de poro-pressão durante a infiltração. Foi proposto um critério de dimensionamento de poços de infiltração através da compensação diária, analisando todos os dias durante 25 anos e utilizando a série histórica de chuvas da região. Esse critério permite selecionar e dimensionar a estrutura ou um grupo de estruturas que melhor atenda ao projeto. O critério proposto permitiu também avaliar o desempenho teórico de sistemas dimensionados utilizando dois critérios convencionais
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Avaliação de elementos de infiltração de águas pluviais na zona norte da cidade de Goiânia / Evaluation of evidence of infiltration of rainwater in the northern city of GoianiaCarvalho, Eufrosina Terezinha Leão 29 August 2008 (has links)
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Previous issue date: 2008-08-29 / The development of the urban environment results in an expansion of impervious ground surfaces that greatly affects the hydrological cycle in the cities. The objective of this research is to evaluate infiltration structures for the control of excess drainage at the origin of runoff. These structures are constructed with the purpose of minimizing the impact of impervious surfaces to the urban environment. An experimental field was established consisting of several infiltration structures, such as small-diameter pilot wells and real scale wells. The real scale wells used perforated concrete pipe casing and brick lining. Falling-head infiltration tests were carried out during 15 months, encompassing the dry and rainy seasons. The infiltration tests were undertaken with initial conditions that correspond to the natural water content at the time of testing. Additional tests were undertaken with previously flooded conditions, reproducing several consecutive rainy days. The monitoring of pilot wells along with real scale wells allowed the evaluation of project parameters obtained from pilot wells. The values of average infiltration rate of different infiltration wells were compared and the performance of the several structures was compared. Laboratory test were carried out for the determination of the hydraulic parameters of the ground profile, including the saturated hydraulic conductivity the soil-water characteristic curve. A numerical model for the simulation of infiltration wells was implemented using the software FlexPDE. Special boundary conditions were developed that take into account the transient relationship between the varying hydraulic head at the well walls and the total volume infiltrated during a test. The numerical simulations contributed for a better understanding of the infiltration mechanism, the influence of the hydraulic conductivity to the infiltration rate, and the determination of the wetting front and pore-water pressures during infiltration. A design criterion for infiltration wells was proposed using daily compensation, considering the daily water balance during 25 years, and the precipitation historical series of the site. The proposed design criterion makes possible the selection of the group of infiltration structures that meet the project goals. The design criterion also allowed the evaluation of the theoretical performance of wells designed using two conventional criteria / A expansão do ambiente urbano causa o aumento das superfícies impermeabilizadas, alterando o ciclo hidrológico nas cidades. Esta pesquisa buscou avaliar estruturas de infiltração para o controle de fluxos superficiais na fonte, construídas com a finalidade de minimizar os impactos da impermeabilização nas cidades. Foi estabelecido um campo experimental composto por diversas estruturas de infiltração, incluindo poços piloto de pequeno diâmetro e poços em escala real. Os poços em escala real foram revestidos em tubo de concreto perfurado e em tijolo maciço assentado em crivo. Ensaios de infiltração com carga variável foram realizados durante 15 meses, abrangendo as estações seca e chuvosa. Os ensaios de infiltração foram realizados em condição inicial de umidade natural e em condição pré-inundada, procurando reproduzir vários dias consecutivos de chuva. O monitoramento dos poços piloto, juntamente com estruturas de infiltração em escala real, permitiu a avaliação dos parâmetros de projetos obtidos a partir dos poços piloto. Os valores de taxa de infiltração média foram comparados entre os diferentes elementos de infiltração e permitiram comparar o desempenho das estruturas. Foram realizados ensaios de laboratório para obtenção de parâmetros hidráulicos do perfil de solo do campo experimental. Dentre as propriedades avaliadas destacam-se a permeabilidade do solo saturado e a curva característica. Um modelo numérico foi implementado utilizando o programa FlexPDE. Foram desenvolvidas condições de fronteira especiais que consideram a dependência transiente entre a carga hidráulica nas paredes do poço e o volume total infiltrado durante o ensaio. A simulação numérica permitiu o melhor entendimento do mecanismo de infiltração, a influência da permeabilidade na taxa de infiltração e a determinação da frente de saturação e da distribuição de poro-pressão durante a infiltração. Foi proposto um critério de dimensionamento de poços de infiltração através da compensação diária, analisando todos os dias durante 25 anos e utilizando a série histórica de chuvas da região. Esse critério permite selecionar e dimensionar a estrutura ou um grupo de estruturas que melhor atenda ao projeto. O critério proposto permitiu também avaliar o desempenho teórico de sistemas dimensionados utilizando dois critérios convencionais
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Auswirkung der portalvenösen Infiltration nach kurativer Resektion duktaler Adenokarzinome des Pankreas auf das Metastasierungsmuster und das progressionsfreie ÜberlebenMierke, Franz 15 December 2017 (has links) (PDF)
Hintergrund: Ziel der Studie war der Vergleich von Patienten mit duktalem Pankreaskarzinom (PDAC) im progressionsfreien und Gesamtüberleben sowie im Rezidivmuster in Abhängigkeit einer Resektion der Vena portae oder der Vena mesenterica superior (PV/SMV).
Methoden: Es wurde eine retrospektive Analyse durchgeführt. Hierbei wurden Patienten betrachtet, die zwischen 2005 und 2015 eine pyloruserhaltende partielle Pankreatoduodenektomie (PPPD), eine klassische Pankreatoduodenektomie (kPD) oder eine totale Pankreatektomie (TP) erhielten. Diese wurden in drei Gruppen eingeteilt. Die P+I+- Gruppe bestand aus Patienten mit Venenresektion (P+), bei denen eine pathohistologische Infiltration der PV oder SMV vorlag (I+). Fand sich bei durchgeführter Venenresektion keine portalvenöse Infiltration (I-), wurden die Patienten der P+I--Gruppe zugeordnet. Als Kontrollgruppe galten Patienten ohne Venenresektion (P-I-), welche zu denen der P+I+- Gruppe gematcht wurden. Die statistischen Analysen wurden mit dem R Softwarepaket durchgeführt. Das Signifikanzlevel wurde für alle Berechnungen auf α = 0,05 festgelegt.
Ergebnisse: Insgesamt wurden 179 Patienten eingeschlossen. 113 erhielten eine portalvenöse Resektion. Davon hatten 36 (31,9%) eine pathohistologische Lumeninfiltration (P+I+), bei 77 (68,1%) lag dagegen keine Infiltration vor (P+I-). 66 Patienten ohne Venenresektion wurden zu den Patienten der P+I+-Gruppe gematcht (P-I-). Zwischen den drei Gruppen waren die meisten pathohistologischen Parameter vergleichbar. 17 Patienten (9,5%) wurden neoadjuvant therapiert, davon erhielten 16 eine Venenresektion (P+). Für das Gesamtüberleben konnten signifikante Unterschiede nachgewiesen werden (11,9 Monate [P+I+] vs. 16,1 Monate [P+I-] vs. 20,1 Monate [P-I-]; p=0,01). In der univariaten Überlebensanalyse konnte für den erhöhten präoperativen CA19-9 Wert, den Resektionsstatus (R), den Lymphknotenstatus (N), das Lymphknotenverhältnis (LNR), die mikroskopische Veneninvasion (V) sowie die pathohistologisch gesicherte Infiltration der PV/SMV ein negativer Einfluss nachgewiesen werden. In der multivariaten Analyse blieb die wahre Infiltration der PV/SMV als einziger signifikanter negativer Einflussfaktor auf das Gesamtüberleben erhalten (p=0,014). Die Inzidenz an Fernmetastasen war in der P+I+- Gruppe signifikant erhöht (75% [P+I+] vs. 45,8% [P+I-] vs. 54,7% [P-I-], p=0,01). Für ein Lokalrezidiv fanden sich dagegen keine Häufigkeitsunterschiede zwischen den Gruppen (p=0,96). Das mediane progressionsfreie Überleben war für Patienten der P+I+-Gruppe signifikant verkürzt (7,4 Monate [P+I+] vs. 10,9 Monate [P+I-] vs. 11,6 Monate [P-I-]; p=0,02). Die Lumeninfiltration der PV/SMV, die mikroskopische Veneninvasion (V), der präoperative CA19-9 Wert sowie der Differenzierungsgrad (G) waren negative Einflussfaktoren auf das progressionsfreie Überleben. In der multivariaten Analyse blieben die pathohistologisch gesicherte Infiltration sowie das Grading als negative unabhängige Einflussfaktoren nachweisbar. In 25% der Fälle manifestierte sich das Rezidiv initial in der Leber.
Schlussfolgerung: Die pathohistologisch gesicherte Infiltration der PV/SMV ist ein unabhängiger Risikofaktor für das progressionsfreie und das Gesamtüberleben. Die Inzidenz an Fernmetastasen ist für die Patienten der P+I+-Gruppe erhöht. Eine potentiell kurative venöse Resektion kann den Einfluss der aggressiven Tumorbiologie und des fortgeschrittenen Krankheitsbildes nicht vollständig kompensieren. / Background. The present study aims to evaluate the longterm outcome and metastatatic pattern of patients who underwent an operation for pancreatic ductal adenocarcinoma (PDAC) with portal or superior mesenteric vein (PV/SMV) resection.
Methods. Patients who underwent a pylorus preserving pancreaticoduodenectomy (PPPD), Whipple procedure (kPD) or total pancreatoduodenectomy (TP) between 2005 and 2015 were retrospectively analyzed. The patients were categorized in three subgroups. Those whom received a vein resection with pathohistological tumor invasion of the PV/SMV (P+I+) those at whom underwent vein resection but without pathohistological tumor invasion (P+I-) and lastly a third group (P-I-) matched to the P+I+ included patients without vein resection. Statistical analysis was performed using the R software package. The significance level for all calculations was set at α = 0.05.
Results. The study cohort included 179 patients, 113 of whom underwent simultaneous PV/SMV resection. 36 patients (31,9%) had pathohistological tumor infiltration (P+I+), 77 (68,1%) did not (P+I-). 66 patients without vein resection (P-I-) were balanced by the P+I+ group. Most of pathohistological tumor characteristics were comparable between groups. 17 patients (9.5%) received neoadjuvant therapy, 16 of them were in vein resection group (P+). The study revealed differences in overall median survival (11.9 months [P+I+] vs. 16.1 months [P+I-] vs. 20.1 months [P-I-]; p=0.01). Univariate survival analysis shown negative consequences for CA19-9, resection margin (R), status of nodal metastasis (N), lymph node ratio (LNR), microvascular vein invasion (V) and true invasion of the PV/SMV. Multivariate survival analysis identified true invasion of the PV/SMV as the only significant, negative prognostic factor (p= 0.01). Whereas the incidence of local tumor recurrence was comparable (p=0.96), the proportion of patients with distant metastasis showed significant differences (75% [P+I+] vs. 45.8% [P+I-] vs 54.7% [P-I-]; p=0.01). The median time to progression were significantly shorter if the PV/SMV was infiltrated (7,4 months [P+I+] vs. 10,9 months [P+I-] vs. 11,6 months [P-I-]; p=0.02). Univariate progression analysis revealed significances for true invasion of the PV/SMV, microvascular vein invasion (V), CA19-9 and histologic classification (G). Multivariate progression analysis detected pathohistological invasion of the PV/SMV and histologic classification (G) as independent factors. Initial liver metastasis occurred in 25% of the patients.
Conclusions. Pathohistological invasion of the PV/SMV is an independent risk factor for overall and progression free survival. Patients of P+I+-group had a higher incidence of distant metastasis, local progression is comparable. Even radical and complete resection cannot completely compensate for aggressive tumor biology and advanced disease.
Modifiziert nach Mierke et al., 2016
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CRITÉRIOS DE DIMENSIONAMENTO DE BIORRETENÇÕES / DESIGNING CRITERIA FOR BIORETENTIONSCadore, Regina Cera 04 February 2016 (has links)
The search for solutions in stormwater management has been a constant in human history. Being a well discussed topic nowadays, public agencies seek for quick solutions in order to minimize the catastrophes caused by floods in result to rapid and disorganized urbanization. Thus, the search for solutions in stormwater management is necessary for maintaining the quality of life, the environment and especially the preservation of the hydrological cycle. Furthermore, infiltration alternatives such as bioretention, trenches and swales have been shown as feasible and well accepted options because they minimize the negative effects of urbanization seeking to restore the natural water cycle. In Brazil, there are few studies focused on design criteria, operation and service-life of these structures, which are important data for the scale of a bioretention otherwise, would be leading to an oversized, costly and underused construction. The main purpose of this study is to analyze the sizing criteria for bioretention systems proposing suggestions for its implementation in the geomorphological conditions of the Santa Maria / RS region. The research evaluates the infiltration structure built in 2010 at the Universidade Federal de Santa Maria (UFSM). The performance of two sizing methodologies was analyzed and the dimensions were compared to the dimensions of the structure implemented at UFSM. The methodology consists of collecting infiltration data from infiltration tests recommended by NBR 13969/97, with some modifications in order to simulate a real event, data of monitoring bioretention at UFSM from 2011 to 2013, and data obtained in the stress test applied to the structure in December 2015. From these data, Horton infiltration curves for the average conditions were adjusted and inserted into the concept of unit infiltration rate (mm.h-1.m-2).The sizing was based on the analyzed methodologies (Curve-Envelope Method and LID method), after the results were compared to the actual behavior of the real structure suggesting adjustments. The results of this study indicate that the methodologies analyzes oversize the bioretention structure. From the analysis of the built bioretention behavior history it can be concluded that despite having smaller dimensions than those obtained through other methodologies sizing, it is effective to storage the drained volume. Therefore, it is clear that the lateral area and the hydrostatic pressure are important to the functioning of the structure, but also the soil-plant relationship, with the creation of preferential paths that end up improving infiltration over the service-life. Further studies are recommended in order to incorporate these items in sizing methodologies, and monitoring of similar structures in order to determine whether the behavior presented by the bioretention is default or an exception. / A procura por alternativas de manejo de águas pluviais sempre foi uma constante na história da Humanidade. Atualmente tem gerado muitos debates, agentes públicos procuram soluções rápidas no intuito de amenizar as constantes catástrofes em decorrências das enchentes e inundações, fruto de uma urbanização acelerada e desorganizada. A busca por inovações se faz necessária para a manutenção da qualidade de vida, do meio ambiente e principalmente pela preservação do ciclo hidrológico. Alternativas de infiltração como biorretenções, trincheiras e valas de infiltração tem se mostrado como opções viáveis e de aprovação geral porque amenizam os efeitos negativos da urbanização buscando restaurar o ciclo hidrológico natural. No Brasil, ainda são poucos os estudos voltados aos critérios de dimensionamento, funcionamento e vida útil das referidas estruturas, que são dados importantes para o profissional dimensionar uma biorretenção, caso contrário, estaria levando a construção de obras superdimensionadas, onerosas e subutilizadas. O objetivo deste trabalho é analisar os critérios de técnicas de dimensionamentos para sistemas de biorretenção e propor sugestões para sua aplicação nas condições geomorfológicas da região de Santa Maria/RS. A pesquisa teve como base a estrutura de infiltração construída, em 2010, na Universidade Federal de Santa Maria. E neste estudo, buscou-se analisar o desempenho de duas metodologias de dimensionamento comparando as dimensões com a estrutura implementada na UFSM. A metodologia utilizada consistiu na coleta de dados de infiltração a partir de: ensaios de infiltração recomendados pela NBR 13969/97, com algumas modificações visando simular um evento real; de dados coletados no monitoramento da biorretenção da UFSM no período de 2011 a 2013 e dados obtidos no Teste de estresse aplicado na estrutura em dezembro de 2015. A partir desses dados, ajustou-se as curvas de infiltração de Horton para as condições médias e inseriu-se o conceito de taxa de infiltração unitária (mm.h-1.m-2). Procedeu-se ao dimensionamento através das metodologias analisadas (Método da Curva-Envelope e Método do LID), após foram analisados os resultados dos dimensionamentos com o comportamento real da estrutura construída no campus Sede da UFSM sugerindo ajustes. Com base nos resultados obtidos neste estudo, os dimensionamentos apresentaram dimensões maiores do que o existente, porém, na análise do histórico da biorretenção construída indica que ela está funcionando perfeitamente no quesito armazenamento. Assim, consta-se a importância da área lateral e da pressão hidrostática no funcionamento da estrutura, como também, a relação solo-planta, com a criação de caminhos preferencias, que acabam melhorando a infiltração ao longo da vida útil. Sendo recomendados novos estudos com o objetivo de incorporar estes itens nas metodologias de dimensionamento, e monitoramento de estruturas semelhantes afim de verificar se o comportamento aqui encontrado é o padrão ou uma exceção.
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Rôle de SOCS1 dans l’immunogénicité de la tumeur en particulier au niveau du carcinome hépatocellulaireAbidi, Maroua January 2017 (has links)
Résumé : Le carcinome hépatocellulaire (HCC) est la troisième cause commune de décès de cancer et affecte plus les hommes que les femmes. Le HCC résulte d’une dérégulation des voies de signalisation impliquées dans l’initiation de l’inflammation menant ainsi à des répercussions désastreuses. De part la complexité de ce type de cancer, les traitements qui existent à ce jour ne sont pas très prometteurs et ont un faible pourcentage de « rémission ». L’immunothérapie soulève beaucoup d’espoir quant à l’orientation vers un traitement efficace plausible. En effet, plusieurs suppresseurs de tumeur se retrouvent réprimés, parmi lesquels le SOCS1. C’est dans cette optique que nos recherches se sont orientées en mettant la lumière sur le SOCS1 «suppresseur de signalisation des cytokines 1 (SOCS1) » qui est réprimé au niveau du HCC et dont la restauration pourrait contribuer à un pronostic favorable à la rémission. La protéine SOCS1 a beaucoup attisé la curiosité des chercheurs de part son rôle suppresseur de tumeur. Pour comprendre les mécanismes d’action de SOCS1 et son implication dans la neutralisation de la tumeur, nous avons généré trois types stables de la lignée cellulaire du carcinome hépatocellulaire de souris Hepa1-6, une portant un vecteur vide, l’autre exprimant le type sauvage du gène SOCS1 (SOCS1-WT; Hepa-S) et une portant une mutation au niveau du domaine SH2 (SOCS1-R105K; Hepa-R). Le mutant ne peut plus inhiber la signalisation des cytokines.
Lors de l'implantation sous-cutanée des cellules Hepa1-6 modifiées, chez des souris C57BL/6 et NOD.scid.gamma (NSG). Nous avons observé que les cellules Hepa1-6 exprimant le vecteur de contrôle (Hepa-V) formaient de grosses tumeurs tandis que les cellules Hepa-S formaient de petites tumeurs chez les deux types de souris. Les cellules Hepa-R quant à elles, formaient de grosses tumeurs seulement chez des souris immunodéficientes (NSG) mais montraient une croissance nettement retardée lorsqu’elles étaient greffées aux souris (C57BL/6) immunocompétentes. Partant de ce constat intrigant, nous avons postulé que SOCS1 favorise l'immunogénicité des cellules tumorales par son domaine SOCS Box. Par conséquent, les cellules Hepa-R offrent une occasion unique de démêler le potentiel pro-immunogène de SOCS1, et ceci dans le but d'élucider les fonctions immunogènes de SOCS1 dans le cancer du foie. Jusqu'à présent aucune précédente recherche ne s’est aventurée à chercher l’implication de SOCS1 dans l’augmentation de l’immunogénicité. / Abstract : Hepatocellular carcinoma (HCC) is the third common cause of cancer deaths and
affects men more than women. HCC results from a disregulation that affects many
factors including inflammation, leading to disastrous repercusions. Due to the
complexity of this type of cancer, existing treatments nowadays are not promising
and have a low remission percentage. Immunotherapy raises great hope regarding
the direction towards a plausible effective treatment. It is in this context that our
research has focused on shedding light on the SOCS1 "signaling suppressor of
cytokine 1 '(SOCS1)" which was found to be suppressed in HCC and whose
restoration could contribute to a favorable prognosis. The SOCS1 many fueled the
curiosity of researchers due to its suppressor role in tumor. To understand the
underlying mechanisms, we generated three types of stable mice cell line
hepatocellular carcinoma Hepa1-6, one carrying an empty vector, the other
expressing the wild-type gene SOCS1 (SOCS1-WT; hepatic S) and carrying a
mutation in the SH2 domain (SOCS1-R105K; Hepa-R). These mutants cannot
inhibit JAK-STAT cytokine signaling.
Upon subcutaneous implantation of the modified Hepa1-6 cells in C57BL/ 6 and
NOD.scid.gamma (NSG) mice, the Hepa1-6 cells expressing the control (Hepa-V)
formed large tumors while the Hepa-S cells formed small tumors in both types of
mice. Hepa-R cells in turn, formed large tumors only in immunodeficient mice
(NSG), but showed a markedly delayed growth when transplanted into (C57BL / 6)
immunocompetent mice. Based on this intriguing finding, we speculate that SOCS1
could promote immunogenicity of tumor cells, which was masked by the ability of
SOCS1 to inhibit signaling of growth factors. Therefore, Hepa-R cells provide a
unique opportunity to unravel the pro-immunogenic potential of SOCS1, and this in
order to elucidate the immunogenic functions of SOCS1 in liver cancer. So far no
previous research studied the potentiel of SOCS1 in increasing immunogenicity.
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