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Groundwater vulnerability assessment using process-based modelsLindström, Riitta January 2005 (has links)
The focus of this thesis is on groundwater vulnerability assessment by process-based simulation models and data acquisition for these assessments. A modelling system for intrinsic groundwater vulnerability assessment in water supply areas was developed, consisting of flow- and transport models for the unsaturated zone and the groundwater zone, coupled to a geographical informa-tion system. The system was applied to a water supply area located close to a major road south of Stockholm. Chloride was used as an indicator in determining the vulnerability for groundwater contamination from the road. The approach was useful to illustrate the dynamic change of chlo-ride concentrations both during the stage of continuous application and after the applications was terminated. A structure and content of a database for flow and transport modelling, based on hydrogeological environments, was outlined. An existing hydrogeological parameter database, HPAR at the Geological Survey of Sweden (SGU), was examined as a potential source of data for the new database. Values for some important parameters needed for groundwater modelling, such as hydraulic conductivity and effective porosity, were lacking in the three municipal HPAR databases that were studied. It was suggested that these data should be added, together with information on the hydrogeological environments, for all geographical positions of interest. Without such minimum information, the efficient use of modelling tools could not be expected. Typical profiles of three common Swedish hydrogeological environments (sand deposits, glacial till and clay covered areas) were used to represent generic input data to model simulations in the unsaturated zone so that the importance of soil, vegetation type and groundwater levels on turn-over times of conservative contaminants transported by natural recharge could be examined. The same profiles were used to predict the penetration depth of accidental liquid spills that occur at the land surface level. In the case of contaminant transport by natural recharge, water storage in the soil profile and vegetation type played an important role for turnover times. For liquid spills, the hydraulic con-ductivity was found to be of major importance, while the water retention properties were of less importance. Modelling, together with available data sources, were successfully used to demon-strate the vulnerability of different environmental conditions. / QC 20101020
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Hydrogeologic conditions controlling contaminant migration from storage tanks overlying Mississippi River Alluvium a case study /Santucci, Jay N. January 2006 (has links)
Thesis (M.S.) -- Mississippi State University. Department of Geosciences. / Title from title screen. Includes bibliographical references.
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Περιβαλλοντική υδρογεωλογική μελέτης της πεδινής ζώνης της βορειοδυτικής Πελοποννήσου με τη χρήση υδροχημικών μεθόδωνΤσελίκα, Ιωάννα 20 September 2010 (has links)
Στα πλαίσια της παρούσας μεταπτυχιακής εργασίας μελετώνται οι υδρογεωλογικές και υδροχημικές συνθήκες που επικρατούν στο βορειοδυτικό τμήμα της Πελοποννήσου. Συγκεκριμένα, η περιοχή μελέτης αποτελεί την βόρεια απόληξη της εκτεταμένης πεδινής έκτασης Πύργου- Αμαλιάδας- Κάτω Αχαΐας, ενώ δίνεται έμφαση στη μελέτη του προσχωματικού υδροφόρου της περιοχής.
Η περιοχή μελέτης γεωλογικά χαρακτηρίζεται από την επικράτηση αποθέσεων του Νεογενούς (Πλειόκαινο) και του Τεταρτογενούς, με τοπικές εμφανίσεις των αλπικών σχηματισμών της Ιόνιας ζώνης, στην οποία ανήκει η περιοχή, σύμφωνα με την γεωτεκτονική διαίρεση του Ελληνικού χώρου.
Οι Πλειοτεταρτογενείς αποθέσεις αποτελούνται από εναλλαγές υδροπερατών, ημιπερατών και υδατοστεγανών σχηματισμών και χαρακτηρίζουν την ανάπτυξη της υπόγειας υδροφορίας που παρουσιάζεται με τη μορφή επάλληλων υπό πίεση ή μερικώς υπό πίεση υδροφόρων οριζόντων. Στην παρούσα εργασία μελετήθηκαν γεωτρήσεις που υδρομαστεύουν στρώματα σε διαφορετικά βάθη. Έτσι στις βαθιές γεωτρήσεις το βάθος φτάνει μέχρι και 170 μέτρα, ενώ στις αβαθείς δεν ξεπερνά τα 40 μέτρα. Η κύρια τροφοδοσία των μελετηθέντων υδροφόρων γίνεται κατά κύριο λόγο από την απευθείας κατείσδυση του νερού των βροχοπτώσεων κυρίως δια μέσου των υπερκείμενων τεταρτογενών αποθέσεων και από τη διήθηση του από τις κοίτες του δικτύου ρεμάτων.
Για την υδροχημική έρευνα χρησιμοποιήθηκε πυκνό δίκτυο δειγματοληψίας νερού σε 21 αρδευτικές γεωτρήσεις της περιοχής έρευνας. Τα νερά των βαθύτερων γεωτρήσεων κατατάσσονται κατά Piper στις εξής ομάδες: α) Κανονικά γαιοαλκαλικά νερά-οξυανθρακικά (Ca-HCO3), β) Κανονικά γαιοαλκαλικά νερά- οξυανθρακικά – θειϊκά (Ca-HCO3-SO4) γ) Γαιοαλκαλικά νερά με υψηλό ποσοστό αλκαλίων - οξυανθρακικά (Ca-Na-Mg-HCO3, Ca-Na-HCO3) και δ) Αλκαλικά νερά- χλωριοθειϊκά (Na-Cl-SO4). Στην τελευταία κατηγορία κατατάσσεται γεώτρηση του Ι. Γ. Μ. Ε με θερμομεταλλικό χαρακτήρα, που πιθανόν να συνδέεται με τις θερμομεταλλικές εμφανίσεις στην ευρύτερη περιοχή της χερσονήσου της Κυλλήνης. Παρατηρείται τοπικά αύξηση της αγωγιμότητας (κυρίως στο βορειοανατολικό τμήμα της περιοχής μελέτης) με παράλληλη αύξηση των ιόντων χλωρίου, λόγω υφαλμύρινσης του νερού του υδροφόρου. Επίσης, παρουσιάζουν αυξημένες συγκεντρώσεις των ιχνοστοιχείων Fe και Mn, που πιθανή προέλευσή τους μπορεί να θεωρηθούν οι κόνδυλοι σιδήρου και μαγγανίου που βρίσκονται μέσα στους κερατόλιθους της ζώνης της Πίνδου, οι οποίοι αναπτύσσονται ανατολικά της περιοχής έρευνας.
Αντίστοιχα, τα νερά των αβαθών γεωτρήσεων ομαδοποιούνται ως εξής: α) Κανονικά γαιοαλκαλικά νερά – οξυανθρακικά (Ca-HCO3), β)Κανονικά γαιοαλκαλικά νερά- οξυανθρακικά – θειϊκά (Ca-HCO3-SO4), γ) Γαιοαλκαλικά νερά με υψηλό ποσοστό αλκαλίων - οξυανθρακικά (Ca-Na-HCO3, Ca-Na-Mg-HCO3, Ca-Na-HCO3-SO4) και δ) Αλκαλικά νερά- χλωριοθειϊκά (Na-Ca-Cl). Αξίζει να υπογραμμίσουμε ότι διαπιστώθηκε σημειακή ρύπανση στο βόρειο και κυρίως στο νοτιοανατολικό τμήμα της περιοχής μελέτης από νιτρικά, λόγω αφ’ενός των κτηνοτροφικών αποβλήτων, και αφ’ετέρου των λιπασμάτων που χρησιμοποιούνται ευρέως στην περιοχή. Παράλληλα, παρατηρείται αύξηση προς τα κατάντη (στο βόρειο τμήμα της περιοχής μελέτης) τόσο της αγωγιμότητας όσο και των ιόντων νατρίου και χλωρίου λόγω της υφαλμύρινσης του υδροφόρου ορίζοντα, συνέπεια των υπεραντλήσεων που συμβαίνουν στην περιοχή.
Μεταξύ των βαθιών και αβαθών γεωτρήσεων παρατηρείται σημαντική διαφοροποίηση ως προς τη θερμοκρασία, με τα νερά των βαθύτερων να εμφανίζουν υψηλότερες θερμοκρασίες λόγω γεωθερμικής βαθμίδας.
Όσον αφορά την ποιότητα του νερού σε σχέση με την άρδευση τα νερά τόσο των βαθιών όσο και των αβαθών γεωτρήσεων χαρακτηρίζονται από μέτρια ποιότητα, καθώς παρουσιάζουν μικρή επικινδυνότητα νατρίου και μέση έως μεγάλη επικινδυνότητα αλατότητας. / In the frame of the present thesis the hydrogeological and hydrochemical conditions that prevail in the the north-western department of Peloponnese are analyzed and interpreted. Concretely, the region of study constitutes the northern ending of extensive flat extent of Pirgos-Amaliada-Kato Achaia. The study emphasizes in the unconfined aquifer of the region.
The geology of the research area is characterized by the predominance of depositions of Neogene (Pliocene) and Quaternary, with local appearances of Alpine shapings of Ionian zone, in which belongs the region, according to the geotectonic division of Greek space.
Plio-Quaternary depositions are constituted by alternations of shapings with small or medium permeability or without permeability and they characterize the growth of the aquifer system that is presented like equitant layers under pressure or partially under pressure of water wagon horizons. In the present work were studied drillings which are collecting water from layers in different depths. Thus in the deep drillings the depth reaches until 170 meters, while in the drillings of smaller depth it does not exceed 40 meters. The main catering of studied water wagon becomes in the first place from the direct percolation of water of rainfalls mainly via means of hypertexts of quaternary depositions and from his filtering from the watercourses of network of streams.
For the hydrochemical research was used dense network of sampling of water in 21 irrigatory drillings of region of research. The waters of deeper drillings are classified at Piper in the following teams: a) Regularly waters (Ca-HCO3), b) Regularly waters- sulphurous (Ca-HCO3-SO4) g) Waters with high percentage of alkalis - (Ca-Na-Mg-HCO3, Ca-Na-HCO3) and [d]) Alkaline waters (Na-Cl-SO4). In the last category is classified drilling of Institute of Geological and Mineral Research with geothermal mineral’s character, that likely it is connected with the appearances of geothermal mineral’s waters in the wider region of the spring of Kyllinis. It’s locally observed increase of conductivity (mainly in the north-eastern department of region of study) with parallel increase of ions of chloride, because of sea water intrusion and as result catio-exchange phenomena took place. Also, they present increased stockings of trace elements Fe and Mn, that likely the cause of their existense can be considered the condyles of iron and manganese that finds in the cherts of area of Pindos, which are developed easternly of the region of research.
Respectively, the waters of shallow drillings are grouped as follows: a) Regularly waters - (Ca-HCO3), b) Regularly waters - sulphurous (Ca-HCO3-SO4), g) Waters with high percentage of alkalis - (Ca-Na-HCO3, Ca-Na-Mg-HCO3, Ca-Na-HCO3-SO4) and [d]) Alkaline waters (Na-Ca-Cl). It deserves we underline that was realised specific pollution in the nothern and mainly in the south-eastern department of region of study from nitric, because on the one hand the veterinary surgeon waste, and on the other hand the fertilizers that are used widely in the region. At the same time, it is observed increase of the conductivity, in the northern department of region of study, with high quantities of ions of sodium and chloride because of the sea water intrusion, consequence of overpumpings that happens in the study area.
Between the deep and shallow drillings is observed important differentiation as for the temperature, with waters of deepest they present higher temperatures because geothermal rung.
With regard to the quality of water concerning the irrigation the waters of so much deep what shallow drillings are characterized by mediocre quality, while present small venturousness of sodium and middle until big venturousness of salinity.
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Modelagem hidrogeológica de uma sub-bacia hidrográfica da Zona da Mata de Minas Gerais / Hydrogeological modeling of a watershed in the zona da mata of Minas GeraisCarvalho, Vinicius Eduardo de Correia 18 March 2013 (has links)
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Previous issue date: 2013-03-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / It is estimated that 35% of Brazil s population are supplied by groundwater and its use increases continuously. Some states, such as São Paulo, Maranhão and Piauí have most of its municipalities served by groundwater sources. Therefore it is necessary not only acquire knowledge about the country's underground water availability, but also the protection of its aquifers and the understanding of their behavior, allowing the management of those resource. The hydrogeological modeling is one of the most used tools in this process. This is the context related to the present work, which consists of the hydrogeological modeling of the Palmital watershed, located in Viçosa, Zona da Mata, Minas Gerais. The modeling process was based on a detailed characterization of the watershed comprising the basis of the area s hydrogeological conceptual model. The characterization included several field activities like six GPR tests, ten survey boreholes, several collections of soil samples for tactile-visual analysis, allocation and monitoring of water level in 6 wells and slug tests in 4 of them. The water balance calculation and estimation of recharge through the hydrographs of monitoring wells were also part of the characterization of the area. This data helped in determined the initial and boundary conditions and the characteristics of the model´s mesh, among other relevant information, allowing the generation of the computational hydrogeological model throughout Visual Modflow® software. Once created, the numerical model went through a calibration process involving WinPest® software, resulting in a normalized standard deviation of 7.1 % and refinement of some hydraulic conductivity parameters. This method has resulted in a good correlation between simulated head data and observed head data (in the field) at the 10 references (wells and springs) used in the calibration. After calibration, the model was validated throughout others 9 springs on the watershed, resulting in a normalized standard deviation of 8.0 %. The simulated aquifer, characterized as porous and free, is widespread, covering much of the basin until a depth of 30 m, which is the lower modeling for the present work. The groundwater flow occurs from areas of higher elevation to the drainage network or to the lower areas of the sub-basin. Once calibrated and validated, the model had its parameters sensitivity evaluated and was found that the hydraulic conductivity and recharge parameters strongly influence the model while conductance of drains have little influence on it. Finally, two hypothetical scenarios were simulated. In each one of them pumping wells were entered into the model, working all with the same flow rate. All wells were installed with 12 m depth, the 2 final meters being its screened interval. The simulations ran with flow rates of 1 and 3 m3·d-1. It was observed that for simulated scenarios, impacts on the aquifer were stronger for higher flow rates, causing the most visible changes of equipotentials curves. Although, insignificant changes in the direction or magnitude of the underground water flow were noted. The changes caused by simulations were easily noticed in places of higher height due to proximity to the edges of the aquifer. / Estima-se que 35% da população brasileira são abastecidos por águas subterrâneas e o seu uso aumenta a cada década. Alguns estados, como São Paulo, Maranhão e Piauí possuem a maioria de seus municípios abastecidos por mananciais subterrâneos. Logo, é necessário não apenas o conhecimento acerca das disponibilidades hídricas subterrâneas do país, mas também a proteção dos aquíferos e a compreensão de seu comportamento, permitindo que a gestão desses recursos possa ser realizada de forma adequada. A modelagem hidrogeológica é uma das ferramentas mais utilizadas neste processo. Esse é o contexto em que se insere o presente trabalho, que consiste na modelagem hidrogeológica da sub-bacia hidrográfica do Córrego Palmital, localizada no município de Viçosa, Zona da Mata de Minas Gerais. A caracterização desenvolvida compreendeu diversas atividades de campo como seis seções de levantamentos com GPR (Radar de Penetração do Solo), dez furos de sondagem, várias coletas de amostras de solo para análise táctil-visual, alocação e monitoramento do nível da água em 6 poços e ensaio de slug test em 4 deles. A caracterização também se baseou em outros trabalhos realizados na área, principalmente nos de Andrade (2010) e Betim (2013). O cálculo do balanço hídrico e a estimativa da recarga através dos hidrogramas do monitoramento dos poços também fizeram parte da caracterização da área, compondo também o modelo conceitual da sub-bacia. De posse desses dados, foram determinadas as condições iniciais, condições de contorno e as características da malha do modelo, dentre outras informações pertinentes, gerando-se o modelo hidrogeológico computacional por intermédio do software Visual Modflow®. Depois de criado, o modelo numérico passou por um processo de calibração envolvendo o software WinPest®, resultando em um desvio padrão normalizado de 7,1 % e no refinamento das condutividades hidráulicas iniciais. Também se obteve uma boa correlação entre os dados de carga simulados e os dados de carga observados em campo nas 10 referências utilizadas, entre poços e nascentes. Após a calibração, o modelo foi validado com base na localização de outras 9 nascentes existentes na bacia, o que gerou um desvio padrão normalizado de 8,0 %. O aquífero simulado, caracterizado como poroso e livre, é extenso, cobrindo grande parte da bacia até uma profundidade máxima em torno de 30 m, sendo este o limite inferior de modelagem, nesta pesquisa. O fluxo subterrâneo ocorre dos locais de maior cota para a rede de drenagem ou para as áreas mais baixas da sub-bacia. Uma vez calibrado e validado, o modelo teve a sensibilidade de seus parâmetros analisada, tendo sido constatado que os parâmetros condutividade hidráulica e recarga influenciam fortemente o modelo, enquanto que a condutância dos drenos exerce pouca influência. Por fim, foram simulados dois cenários hipotéticos em que foram inseridos poços de bombeamento que trabalhavam com a mesma vazão, todos com 12 m de profundidade, com seção filtrante localizada nos 2 m finais. Nos cenários 1 e 2, as vazões usadas nas simulações foram de 1 e 3 m3·d-1, respectivamente. Observou-se nos cenários simulados que os impactos ao aquífero são mais fortes para a maior vazão provocando alterações mais visíveis das equipotenciais. Não se obervaram mudanças significativas na direção ou na magnitude do fluxo hídrico subterrâneo. As alterações provocadas pelas simulações são facilmente notadas nos locais de maiores cotas devido à proximidade com as bordas do aquífero.
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“Caracterização hidrogeológica do Sistema Aquífero Bauru na área urbana de Primavera do Leste/MT”Zimmer, Jefferson Richard 16 October 2014 (has links)
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Previous issue date: 2014-10-16 / CAPES / Neste trabalho foi realizada a caracterização hidrogeológica do Grupo Bauru na área urbana de Primavera do Leste, usando dados existentes de poços tubulares, de geologia, de morfopedologia e de sondagem elétrica vertical. O Sistema Aquífero Bauru foi avaliado usando, condutividade hidráulica, coeficiente de armazenamento, nível estático, vazão, profundidade de poços e dados de qualidade de água. Os poços que explotam o Bauru foram analisados em termos de estrutura técnica e perfil geológico. Os resultados mostram que, na área, o Bauru tem características hidráulicas similares ao restante do Brasil, indicando boa capacidade para produção de água, conforme mostram as vazões dos poços tubulares. As suas águas são ácidas, alguns locais apresentam teor de ferro acima do VMP, porém podem ser consideradas potáveis. Os poços tubulares menos de 10% atendem os critérios técnicos das normas da ABNT, o que pode está contribuindo para alguns problemas locais de qualidade dessas águas, como turbidez, ferro, etc. O conhecimento e os dados produzidos constituem uma ferramenta indispensável para embasar a política de gestão de recursos hídricos nesta cidade e a realização de campanhas educativas voltadas ao uso sustentável dessas águas. / In this work the hydrogeological characterization of the Bauru Group was held in the urban area of Primavera do Leste, using existing data from wells, geology, morfopedologia and vertical electrical sounding. The Bauru Aquifer System was evaluated using hydraulic conductivity, storage coefficient, static water level, discharge, depth of wells and water quality data. The wells that explotam the Bauru were analyzed in terms of technical structure and geological profile. The results show that, in the area, Bauru is similar hydraulic characteristics to the rest of Brazil, indicating a good production capacity water, as shown the discharge wells. Its waters are acidic, some places have iron content above the VMP, but can be considered potable. The wells less than 10% meet the technical criteria of ABNT, which can is contributing to some local water quality problems such as turbidity, iron, etc. The knowledge and data produced are an essential to support the policy of water management in the city and performing on the sustainable use of these waters educational campaigns tool.
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Estimativa de parâmetros hidrogeológicos como subsídio para modelagem de aqüífero integrada a estudos geofísicos na região de Bebedouro-SP / Estimating hydrogeological parameters as subsidy for aquifer modelling integrated to geophysical studies in Bebedouro-SP region.Ivan Mamede Carlos 30 August 2010 (has links)
Realizar a modelagem de um aqüífero não é tarefa fácil. Em se tratando de um sistema aqüífero, a empreitada se torna ainda mais complexa. Neste trabalho, alguns dos parâmetros importantes para esse fim foram estimados a partir de simulações. Na região de estudo, existem poços tubulares que, em sua maioria, não foram perfurados somente na Formação Adamantina, mas também na Formação Serra Geral. Tal configuração conduziu à formulação de dois conjuntos de cenários a partir dos quais foi possível estimar valores de condutividade hidráulica para as duas formações. Com essa estimativa conseguiu-se também simular testes de bombeamento, seus respectivos cones de rebaixamento, bem como a interferência causada entre cones de rebaixamento. Com essa abordagem foi possível estimar o quanto um poço em funcionamento pode influenciar no nível estático de um vizinho. A contribuição da geofísica está no uso da eletroresistividade. Foram executadas 23 Sondagens Elétricas Verticais (SEV), das quais dezenove são SEV´s curtas (AB/2 500m) e quatro, longas (AB/2 1500), que forneceram informações sobre a espessura saturada do arenito e posição do topo do basalto, especialmente na região com poucos poços. Também foram realizados quatro Caminhamentos Elétricos (CE) no estudo de possíveis estruturas. Unindo os resultados da modelagem (simulação) e da geofísica, pôde-se relacionar os parâmetros hidrogeológicos e geoelétricos. Embora o conjunto de dados para a região não tenha sido o ideal, a metodologia se mostrou adequada e os resultados bastante razoáveis. Deste modo, foi possível a determinação de parâmetros hidrogeológicos em subsuperfície através de parâmetros geoelétricos medidos em superfície. / To perform the aquifer modelling is not an easy task. In the case of an aquifer system, the work becomes even more complex. In this work, some of important parameters for this purpose have been estimated from simulations. In the study area, there are wells that in most cases were not only drilled in Adamantina Formation but also in Serra Geral Formation. This configuration led to the formulation of two sets of scenarios from which it was possible to estimate values for hydraulic conductivity of these formations. With this estimate it could also simulate pumping tests, their cones of depression as well as the interference caused between cones of depression. With this approach it was possible to estimate how much a operating well can influence static level of a neighbour one. Geophysics contribution is in the use of electrical resistivity. Twenty-three Vertical Electrical Soundings (VES) were performed, nineteen of them are short (AB/2 500m), that provided information about the saturated thickness of sandstone as well as top of basalt, especially in the region with few wells, and four are long (AB/2 1500) VESs. Four electrical profiling (EP) were also carried out to study possible structures. Joining modelling (simulation) and geophysics results, it could be related hydrogeological and geoelectrical parameters. Although dataset for region was not the ideal, methodology was satisfactory, and results quite reasonable. Thus, it was possible to determine hydrogeological parameters in subsurface through measured geoelectrical parameters in surface.
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Integrating Field and Modeling Studies to Assess the Response of a Lake-Groundwater System to Mining ActivitiesTauscher, Tyler Lee 25 May 2022 (has links)
No description available.
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Apports d’une approche couplée physique et géochimie des eaux souterraines pour caractériser les fonctionnements hydrodynamiques transitoires. Cas de la plaine alluviale du Forez. / Contribution of a coupled geochemical and physical approach for the characterization of transient groundwater flow applied to the Forez Plain (France, Loire 42).Re-Bahaud, Jordan 22 October 2012 (has links)
Le diagnostic du SAGE Loire au niveau de la plaine du Forez (42) relate une dégradation du potentiel hydrogéologique et une pollution des nappes superficielles par les nitrates et les pesticides. Ces problèmes nécessitent une gestion durable et équilibrée de la ressource en eau. Une partie de la demande en eau est assurée par la ressource souterraine. Les eaux souterraines exploitées sont : les eaux des formations alluviales superficielles pour l’irrigation et l’AEP ; et les eaux minérales des niveaux aquifères profonds du bassin sédimentaire sous-jacents aux alluvions pour le thermalisme et de mise en bouteille.La synthèse des connaissances disponibles a révélé des insuffisances dans la description des aquifères superficiels. En effet, elles ne permettent pas d’appréhender comment fluctue la ressource dans le temps et ne prennent pas en compte l’origine de la recharge des aquifères superficiels. Ainsi, le travail de thèse se focalise sur ces deux points particuliers :- l’identification du fonctionnement transitoire des aquifères est abordée par caractérisation physique des écoulements s’appuyant sur l’analyse de 4 points de suivi piézométrique permanent et la modélisation numérique des écoulements permettant de reproduire les fluctuations piézométriques observées.- l’origine de la recharge des aquifères alluviaux est abordée par caractérisation géochimique des écoulements (analyses en ions majeurs et isotopes δ180, δ2H, δ13C et A14C). Cette approche a mis en évidence des apports d’eaux profondes alimentant localement les aquifères superficiels.La méthodologie proposée, couplée physique et géochimie, permet de mieux préciser la vulnérabilité des aquifères investigués, en vue d’une meilleure gestion future. / The Water Management Scheme in the Forez plain (France 42) has concluded to a degradation of the water resources and a serious pollution of the shallow aquifers by nitrogen and pesticides. These issues require a sustainable and balanced management of the water resources. A part of the water demand is met by groundwater. The exploited groundwater come from: shallow alluvial formations exploited for irrigation and drinking water and deep aquifers in sedimentary basin under the alluvium. Mineral waters from the deep aquifers are exploited for thermo-mineral activities and bottling.The analysis of the data available in the studied area revealed a lack of knowledge in the understanding of the groundwater flow in the shallow aquifers. Is not sufficient to explain how the water resource varies with time and the origin of the recharge of the shallow aquifers. As consequence, this thesis work will focus on these two main topics: - Identification of the transient functioning of the aquifers based on a physical characterization of groundwater flow. This method is based on piezometric head analysis carry out on 4 stations with continuous measurements and numerical modeling to compare with the observed piezometric fluctuations.- Identification of the origin of the recharge of the alluvial aquifers through a geochemical characterization of groundwater flow (major ions and isotopes δ180, δ2H, δ13C and A14C). This approach established the partial contribution of the deep aquifers to the groundwater flow in the shallow alluvium. This methodology based on a coupled geochemical and physical approach allows to assess the vulnerability of the studied aquifers and contributes to improve the future water resources management in this area.
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Riktvärden för förorenad mark : En undersökning av hur riktvärden för förorenad mark har förändrats gentemot tidigare riktvärden samt hur de påverkas av variationer i geologiska och hydrogeologiska parametrarLevin, Sara January 2009 (has links)
<p>Risk assessment is made to determine risks with contaminated areas and to determine which treatment the area requires. In Sweden, risk assessment is divided into three levels: risk analysis, facilitated risk assessment and detailed risk assessment. In detailed risk assessment site-specific guideline values are developed to compare with values of contaminants that are measured in the area.</p><p>Site-specific guideline values vary with geological and hydrogeological parameters. The purpose of this report is to examine which of these parameters that affect the guideline values. The examination was done using a calculating program for consideration from the Swedish Environmental Protection Agency from the year of 1997. The study shows that some of the geological and hydrogeological parameters affect the site-specific guideline values for metals in different ways and others do not. </p><p>Using the program from the Swedish Environmental Protection Agency is a simple way to calculate site-specific guideline values. It’s important to make sure that relevant values are chosen to get correct results. The calculating program is still not definitive so it’s important to be careful when using it.</p><p>Another purpose of the report is to compare how guideline values have developed from the Swedish Environmental Protection Agency’s model for calculating guideline values from the year of 1997 with their new report whit the same purpose from the year of 2007. Guideline values for all metals that have been considered are lower in the new model from the year of 2007 compared to the model from the year of 1997.</p>
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Hydrogeological data modelling in groundwater studiesWojda, Piotr 19 January 2009 (has links)
Managing, handling, exchanging and accessing hydrogeological information depend mainly on the applied hydrogeological data models, which differ between institutions and across
countries. Growing interest in hydrogeological information diffusion, combined with a need for information availability, require the convergence of hydrogeological data models. Model
convergence makes hydrogeological information accessible to multiple institutions, universities, administration, water suppliers, and research organisations, at different levels: from the local level (on-site measurement teams), to national and international institutions dealing with water resources management. Furthermore, because hydrogeological studies are complex, they require a large variety of high-quality hydrogeological data with appropriate
metadata in clearly designed and coherent structures.
To respond to the requirement of model convergence, easy information exchange and hydrogeological completeness, new data models have been developed, using two different methodologies. At local-regional level, the HydroCube model has been developed for the Walloon Region in Belgium. This logical data model uses entity-relationship diagrams and it
has been implemented in the MS Access environment, further enriched with a fully functional user-interface. The HydroCube model presents an innovative holistic project-based approach, which covers a full set of hydrogeological concepts and features, allowing for effective hydrogeological project management. This approach enables to store data about the
project localisation, hydrogeological equipment, related observations and measurements. Furthermore, topological relationships facilitate management of spatially associated data. Finally, the model focuses on specialized hydrogeological field experiments, such as pumping tests and tracer tests.
At the international level, a new hydrogeological data model has been developed which guarantees hydrogeological information availability in one standard format in the scope of the FP6 project GABARDINE (Groundwater Artificial recharge Based on Alternative sources of wateR: aDvanced Integrated technologies and management). The model has been
implemented in the ArcGIS environment, as a Geospatial Database for a decision support system. The GABARDINE Geospatial Database uses advantages of object-oriented modelling (UML), it follows standards for geoscientific information exchange (ISO/TC211 and OGC), and it is compliant with the recommendations from the European Geospatial Information Working Group.
Finally, these two developed models have been tested with hydrogeological field data on different informatics platforms: from MS Access, through a proprietary ArcGIS environment, to the open source, free Web2GIS on-line application. They have also contributed to the development of the GroundWater Markup Language (GWML) Canadian exchange standard, compliant with Geographic Markup Language (GML). GWML has the potential of becoming an international HydroGeology Markup Language (HgML) standard with a strong and continuous support from the hydrogeological community.
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