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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
471

Avaliação geológico-geotécnica da área do lixão de Poços de Caldas (MG): problemas ambientais, modelagem de fluxo e de transporte de poluentes e medidas de remediação / not available

Janaina Barrios Palma 20 April 1999 (has links)
O presente trabalho apresenta os resultados obtidos na avaliação dos problemas ambientais relacionados a lixiviação de poluentes do lixão próximo ao Ribeirão dos Moinhos na cidade de Poços de Caldas (MG). O estudo considera as características geológicas - geotécnicas e climáticas da área e os vários tipos de técnicas de \"cleanup\". O software Visual Modflow foi usado para desenvolver simulações em termos de fluxo de água subsuperficial e de transporte de poluentes. / This work presents the results obtained from assessment of the environment problems related to the pollutant lixiviation from the urban wastes disposed near the Moinho River in Poços de Caldas (MG) city. The study considered the geological - geotechnical and climatic characteristics of the area and the main kinds of cleanup techniques. The software Visual Modflow were used to developed the simulation in terms of groundwater flow and pollutant transport.
472

Hydrological and hydro-geological model of the Western Dead Sea catchment, Israel and West Bank

Sachse, Agnes Christiane Felicia 05 April 2017 (has links) (PDF)
Groundwater is the only fresh water resource in the semi-arid to hyper-arid Western Dead Sea catchment. Due to exploitation of groundwater the water level is decreasing in the surrounding Cretaceous aquifer system and sustainable water management is needed in order to prevent the progressive yields and contamination of those water resources. In addition, the water level of the Dead Sea decreases dramatically by at least one meter per year. This is connected to channel off the water from the Jordan River to supply intensive agriculture in the semi-arid to hyper-arid region. Hydrological and hydro-geological analysis and modelling in arid regions, like the study area, frequently suffer from data scarcity and uncertainties regarding rainfall and discharge measurements. The study showed that spatial and temporal interpolations as well as additional methods (e.g. empirical relationships and simultaneous numerical approaches) were suitable tools to overcome data shortage for modelling. Water balances are the result of a calibrated model and are the basis for sustainable management of surface and subsurface water resources. The present study investigates beside the hydrological characterisation of selected sub-catchments (wadis) also the hydro-geology of the Judean limestone aquifer and calculates a comprehensive water balance of the entire western flank of the Dead Sea by the application of two numerical open source codes: OpenGeoSys (OGS) and J2000g. The calibrated two-dimensional hydrological model J2000g provides a 33 years time series of temporal and spatial distributed groundwater recharge for the numerical groundwater flow model of OGS. The mean annual groundwater recharge of 139.9 · 10^6 m^3ˑ a^-1 is nearly completely depleted by abstractions from pumping wells close to the replenishment area in the Judea Mountains.
473

APPLICATION OF A GROUND-WATER FLOW MODEL TO THE MESILLA BASIN, NEW MEXICO AND TEXAS

Hamilton, Susan Lynne, Maddock, Thomas III January 1993 (has links)
It has been said that watersheds and aquifers ignore political boundaries. This phenomenon is often the reason for extensive regulation of surface -water and ground -water resources which are shared by two or more political entities. Regulation is often the result of years of litigation over who really owns the water, how much is owned, and how much is available for future use. Groundwater models are sometimes used as quantitative tools which aid in the decision making process regarding appropriation and regulation of these scarce, shared, water resources. The following few paragraphs detail the occurrences in the Lower Rio Grande Basin which led to the current ground -water modeling effort. New Mexico, Texas and Mexico have wrestled forever over the rights to the Lower Rio Grande and the aquifers of the Rio Grande Basin (Figure 1). As early as 1867, due to a flood event on the Rio Grande, Texas and Mexico were disputing the new border created by the migrating Rio Grande. During the 1890's, the users upstream from the Mesilla and El Paso Valleys were diverting and applying so much of the Rio Grande that the Mesilla and El Paso valley farmers litigated in order to apportion and guarantee the supply. In the recent past, disputes over who may use the ground -water resources of the region and the effect of surface- water uses on aquifer water levels resulted in litigation between El Paso, Texas, and New Mexico.
474

Méthodes de volumes finis pour des équations aux dérivées partielles déterministes et stochastiques / Finite volume methods for deterministic and stochastic partial differential equations

Gao, Yueyuan 10 December 2015 (has links)
Le but de cette thèse est de faire l'étude de méthodes de volumes finis pour des équations aux dérivées partielles déterministes et stochastiques; nous effectuons des simulations numériques et démontrons des résultats de convergence d'algorithmes.Au Chapitre 1, nous appliquons un schéma semi-implicite en temps combiné avec la méthode de volumes finis généralisés SUSHI pour la simulation d'écoulements à densité variable en milieu poreux; il vient à résoudre une équation de convection-diffusion parabolique pour la concentration couplée à une équation elliptique en pression. Nous présentons ensuite une méthode de simulation numérique pour un problème d'écoulements à densité variable couplé à un transfert de chaleur.Au Chapitre 2, nous effectuons une étude numérique de l'équation de Burgers non visqueuse en dimension un d'espace, avec des conditions aux limites périodiques, un terme source stochastique de moyenne spatiale nulle et une condition initiale déterministe. Nous utilisons un schéma de volumes finis combinant une intégration en temps de type Euler-Maruyama avec le flux numérique de Godunov. Nous effectuons des simulations par la méthode de Monte-Carlo et analysons les résultats pour différentes régularités du terme source. Il apparaît que la moyenne empirique des réalisations converge vers la moyenne en espace de la condition initiale déterministe quand t → ∞. Par ailleurs, la variance empirique converge elle aussi en temps long, vers une valeur qui dépend de la régularité et de l'amplitude du terme stochastique.Au Chapitre 3, nous démontrons la convergence d'une méthode de volumes finis pour une loi de conservation du premier ordre avec une fonction de flux monotone et un terme source multiplicatif faisant intervenir un processus Q-Wiener. Le terme de convection est discrétisé à l'aide d'un schéma amont. Nous présentons des estimations a priori pour la solution discrète dont en particulier une estimation de type BV faible. A l'aide d'une interpolation en temps, nous démontrons deux inégalité entropiques vérifiées par la solution discrète, ce qui nous permet de prouver que la solution discrète converge selon une sous-suite vers une solution stochastique faible entropique à valeurs mesures de la loi de conservation.Au Chapitre 4, nous obtenons des résultats similaires à ceux du Chapitre 3 dans le cas où la fonction flux n'est pas monotone; le terme de convection est discrétisé à l'aide d'un schéma monotone. / This thesis bears on numerical methods for deterministic and stochastic partial differential equations; we perform numerical simulations by means of finite volume methods and prove convergence results.In Chapter 1, we apply a semi-implicit time scheme together with the generalized finite volume method SUSHI for the numerical simulation of density driven flows in porous media; it amounts to solve a nonlinear convection-diffusion parabolic equation for the concentration coupled with an elliptic equation for the pressure. We then propose a numerical scheme to simulate density driven flows in porous media coupled to heat transfer. We use adaptive meshes, based upon square or cubic volume elements.In Chapter 2, We perform Monte-Carlo simulations in the one-dimensional torus for the first order Burgers equation forced by a stochastic source term with zero spatial integral. We suppose that this source term is a white noise in time, and consider various regularities in space. We apply a finite volume scheme combining the Godunov numerical flux with the Euler-Maruyama integrator in time. It turns out that the empirical mean converges to the space-average of the deterministic initial condition as t → ∞. The empirical variance also stabilizes for large time, towards a limit which depends on the space regularity and on the intensity of the noise.In Chapter 3, we study a time explicit finite volume method with an upwind scheme for a first order conservation law with a monotone flux function and a multiplicative source term involving a Q-Wiener process. We present some a priori estimates including a weak BV estimate. After performing a time interpolation, we prove two entropy inequalities for the discrete solution and show that it converges up to a subsequence to a stochastic measure-valued entropy solution of the conservation law in the sense of Young measures.In Chapter 4, we obtain similar results as in Chapter 3, in the case that the flux function is non-monotone, and that the convection term is discretized by means of a monotone scheme.
475

Výpočet sedání výškové budovy s využitím metody konečných prvků / Prediction of foundation settlement of high-rise building using the finite element method

Červenka, Jan January 2020 (has links)
The focus of this thesis is to deal with reverse engineering of high-rise building settlements. This is modeled via the finite element method performed in the Plaxis 3D program. In the first part of this thesis, a calibration of input parameters of an appropriate material model – Hardening soil – is conducted. This calibration is a result of oedometric test data which were obtained within a geotechnical survey. An influence of soils over consolidation affecting calibration and the material model choice is described. Final values of reference stiffness parameters are used in a mathematical model of the focused area. This model is created for one half of the high-rise building plan, including vestibule. The high-rise building is founded in a foundation pit. The foundations of this building consist of raft foundation and piles of jet grouting. In the model, there are also changes in pore pressure during an excavation of foundation pit included. The functional model is used for parametric analyses, namely examining cases of object´s foundations and the possible influence of foundation pit´s symmetry on the object´s settlement. All the calculated processes in the object´s settlements are then compared to data obtained from geotechnical monitoring of the structure.
476

Modélisation intégrée des écoulements souterrains et des échanges nappe-rivière dans la basse vallée du Var / Integrated hydraulic modeling of groundwater flow and river-aquifer exchanges in the lower valley of Var River

Du, Mingxuan 09 December 2016 (has links)
La modélisation hydraulique avec modèle déterministe est une méthode largement utilisée. Cependant,lamodélisation est un ptocessus complexe, notamrnent pour les aquifères où la quantité et la qualité desdonnées ne sont pas satisfaisantes. Etantune des sources pdncipales de I'eau douce dans la basse valléedu Var, Côte d',{.zur,Frarrce,la nappe libre de lavallée est menacée parla pénurie et la pollution. Maþéle grand nombre d'études effectuées dans cette zone, la dynamique des écoulements souterrains esttoujours patiellement inconnue. Par conséquent, la métropole Nice Côte d'Azur a besoin de développerun système d'aide à la décision (SÂD) à base des modèles numériques afin d'assurer une gestion plusefficace de l'eau souteraine. Un modèle numérique est développé avec FEFLO\ø en tenant compte desprécipitations, de l'é:vapoftanspiration, du pompage de l'eau souterraine, et des échanges nappe-rivière.Le volume d'eau pompée pour l'usage agdcole et le taux d'échange du lit mineur du Var ont été calibrés.Le modèle a été. vabdé. par une simulation de '1.266 jours. Le modèle est utilisé pour simuler les scénatüdes événements d'inondation et de sécheresse, les scénadi de pollution et l'intrusion d'eau de mer dans lavallée. Une première conception du système d'aide à la décision est présentée comme le demier exemplede l'application du modèle. Une interface de couplage est développée en Java et sert à échanger lesdonnées entre le modèle souterrain et le modèle à surface libre élaboré avec MIKE21FM. / Groundwater modeling with deterministic model is a complicated process, especially in complex aquiferswhere the quantity and the quality of the measuted data arc not satisfying. The unconfined alluvialaquifet is the main water resource in the lower valley of Vat river, Ftench Riviera, but it faces a thteat ofshortage and pollution. Despite numerous previous studies, the dynamics of the gtoundwater flow in thealluvial aquifer and the characteristics of the rivet-aquifer exchanges ¿re s':ll partially unknown.Therefore the local u/ater management service requires a decision support system PSS) based onnumerical models to ensure a better groundwater management. A hydraulic model is set up withFEFLO!ø software by considedng ptecþitation, evâpotranspiration, gtoundwatet exftacdon and rivetaquiferexchanges. The non-documented groundwater exttaction fot agticultural use and the transferrates in the dverbed along the river have been calibtated. The model has been validated with asimulation of 7266 days. The model is applied to simulate the scenarios of flood and drought events, thepollution events in the unconfined aquifer in the valley and the seawater inrusion in the estuary of Yarriver. These case studies contributes to increase the knowledge of the aquifet. A fust conception of theDSS tool is presented as the last example of model application. A coupling interface is developed thanksto aJava which enables an automatic exchange of data between the groundwater flow model and thesurface wâter flow model built with MII(E2ltr}'/. More tests should be done to validate the couplinginterface
477

Zpracování komplexního karotážního měření / Data processing of well log complex

Hanák, David January 2018 (has links)
This thesis is focused on the problem of the determination of shear surfaces of slope instabilities (including fossil ones) from the results of the complex of logging methods. It describes the steps taken during data measurement, processing, and interpretation. All the data comes from the measurements conducted in the boreholes carried out for the geotechnical survey of the sliding area in the immediate proximity of the D8 highway or measurements in a well from the Děčín-Loubí locality. On the second mentioned locality, due to a different well construction, a more extensive logging complex could be carried out. After locating shear surfaces in a slope instability, a comparsion was made to determine whether the results in neighboring boreholes corresponded to each other, and to evaluate which methods (or combination of methods) suits best for the task.
478

Hydrological and hydro-geological model of the Western Dead Sea catchment, Israel and West Bank

Sachse, Agnes Christiane Felicia 01 April 2016 (has links)
Groundwater is the only fresh water resource in the semi-arid to hyper-arid Western Dead Sea catchment. Due to exploitation of groundwater the water level is decreasing in the surrounding Cretaceous aquifer system and sustainable water management is needed in order to prevent the progressive yields and contamination of those water resources. In addition, the water level of the Dead Sea decreases dramatically by at least one meter per year. This is connected to channel off the water from the Jordan River to supply intensive agriculture in the semi-arid to hyper-arid region. Hydrological and hydro-geological analysis and modelling in arid regions, like the study area, frequently suffer from data scarcity and uncertainties regarding rainfall and discharge measurements. The study showed that spatial and temporal interpolations as well as additional methods (e.g. empirical relationships and simultaneous numerical approaches) were suitable tools to overcome data shortage for modelling. Water balances are the result of a calibrated model and are the basis for sustainable management of surface and subsurface water resources. The present study investigates beside the hydrological characterisation of selected sub-catchments (wadis) also the hydro-geology of the Judean limestone aquifer and calculates a comprehensive water balance of the entire western flank of the Dead Sea by the application of two numerical open source codes: OpenGeoSys (OGS) and J2000g. The calibrated two-dimensional hydrological model J2000g provides a 33 years time series of temporal and spatial distributed groundwater recharge for the numerical groundwater flow model of OGS. The mean annual groundwater recharge of 139.9 · 10^6 m^3ˑ a^-1 is nearly completely depleted by abstractions from pumping wells close to the replenishment area in the Judea Mountains.:Acknowledgements Abstract Nomenclature Content List of Figures List of Tables 1 Introduction 1.1 Motivation 1.2 State of the Field 1.3 General research questions 1.4 Challenges 1.5 Structure of the Thesis 2 Theory and Methods 2.1 Data analysis 2.2 Governing equations 2.2.1 Surface Flow - Hydrological Model: J2000g 2.2.2 Subsurface Flow - Groundwater Flow Model: OpenGeoSys 2.3 Groundwater recharge 3 Study area 3.1 Study site selection 3.2 Geography 3.2.1 Climate 3.2.2 Soils 3.2.3 Vegetation 3.2.4 Land use 3.3 Hydrology 3.3.1 Wadis 3.3.2 Flashfloods 3.3.3 Dead Sea 3.4 Geology 3.5 Hydro-geology 3.5.1 Springs 3.5.2 Well fields 4 Hydrological Model 4.1 Conceptual Model 4.2 Hydrological Model J2000g 4.2.1 Data base 4.2.2 Simulation results from J2000g 5 Structural geological model 5.1 Stratigraphy 5.2 Database 5.3 Workflow 6 Numerical groundwater flow model 6.1 Work flow of 2D and 3D meshing 6.2 Parametrisation 6.3 Boundary conditions 6.4 Model Set-up 6.5 Calibration of Steady-State model 6.6 Transient Model 6.6.1 Model assumptions 6.6.2 Challenges 6.6.3 Preliminary results 7 Conclusions and Outlook 7.1 Important results from the hydrological model 7.2 Important results from the geological structural model 7.3 Important results from the hydro-geological model 7.4 Deficiencies 7.5 Outlook References 8 Enclosed Publications
479

A Concept for the Investigation of Riverbank Filtration Sites for Potable Water Supply in India

Sandhu, Cornelius Sukhinder Singh 31 August 2016 (has links)
Die Uferfiltration (UF) ist eine potentielle Alternative zur konventionellen Oberflächenwasseraufbereitung in Indien, da Trübstoffe, pathogene Mikroorganismen und organische Wasserinhaltsstoffe effektiv entfernt werden. In dieser Arbeit wurde erstmals ein umfangreicher Überblick zu bestehenden UF-Anlagen in Indien erarbeitet. Für die Standorterkundung und -bewertung wurde ein Konzept erarbeitet, das an drei Standorten entlang des Ganges getestet und weiterentwickelt wurde. Das Konzept umfasst vier Stufen: Standortvorerkundung, Bestimmung von Grundwasserleiterparametern, Erfassung von hydraulischen und Beschaffenheits-parametern sowie numerische Grundwasser-strömungsmodellierung. Entlang des oberen Flusslaufes des Ganges (Haridwar und Srinagar) wurden günstige geohydraulische Verhältnisse identifiziert (kf = 10E-4 bis 10E-3 m/s, Grundwasser leitermächtigkeit 11 bis 20 m). Entlang des unteren Flusslaufes (Patna) gibt es in Abhängigkeit von der Mächtigkeit der Sedimentablagerungen im Ganges nur bei erhöhter Schleppkraft im Monsun eine gute hydraulische Verbindung zwischen dem Fluss und dem Grundwasserleiter. In Haridwar wurde der Uferfiltratanteil im Rohwasser mittels Isotopenanalysen (δ18O) und Leitfähigkeitsmessungen im Fluss- und Rohwasser ermittelt. Der Uferfiltratanteil in den auf einer Insel und südlich davon gelegenen Brunnen liegt bei bis zu 90%. An den untersuchten Standorten wird durch die UF eine effektive Entfernung von E. coli um 3,5 bis 4,4 Log10 und der Trübung bis >2 Log10 Einheiten erreicht. Eine Entfernung von 3 Log10 Einheiten wurde bereits bei einer Fließzeit des Uferfiltrats von zwei Tagen beobachtet. Die erhöhte Anzahl an Coliformen in einigen Brunnen am Standort Haridwar resultiert aus Verunreinigungen des landseitigen Grundwassers. Bei Hochwässern und Starkregenereignissen muss eine Kontamination durch den direkten Eintrag von Wasser durch undichte Brunnenabdeckungen, Risse in den Schächten bzw. unsachgemäßen Brunnenbau berücksichtigt werden. Die Anwendung des angepassten Untersuchungskonzepts an 15 weiteren UF-Standorten in Indien hat gezeigt, dass die niedrigen DOC-Konzentrationen im Flusswasser (0,9 bis 3,0 mg/L) und im Brunnenwasser (0,4 bis 2,3 mg/L) günstig für die Anwendung der UF sind. Bei erhöhten DOC-Konzentrationen (Vormonsun) im Flusswasser konnte in Delhi und Mathura im Monsun eine 50%ige Verminderung erreicht werden. Bei der Erkundung neuer UF-Standorte in bergigen Gebieten sind die Grundwasserleitermächtigkeit mit geophysikalischen Erkundungsverfahren, die Strömungsverhältnisse in den alluvialen Ablagerungen sowie lokale Hochwasserrisiken zu untersuchen.:Abstract i (Seitenzahl / page number) Acknowledgements iii Table of contents v List of tables viii List of figures ix Abbreviations and symbols xi 1 Introduction 1 1.1 Problem description 1 1.2 Riverbank filtration and its potential in India 2 1.3 Motivation 3 1.4 Aims 4 2 Bank filtration in context to India’s water resources 5 2.1 Water budget of India and the Ganga River catchment 5 2.1.1 Water budget 5 2.1.2 The Ganga River catchment 6 2.2 Problems of surface water abstraction for drinking water production 8 2.2.1 Effect of low surface flows on the quantity of raw water abstraction 8 2.2.2 Effect of the monsoon on conventional drinking water treatment plants using directly abstracted surface water 9 2.2.3 Quality of surface water 10 2.2.4 Treatment of directly abstracted surface water for drinking 11 2.3 Sustainability issues of groundwater abstraction 11 2.4 Drinking water consumption in India 12 2.5 Bank filtration for water supply 14 2.5.1 Geohydraulic, siting and design aspects of bank filtration systems 14 2.5.2 Water quality aspects 15 2.5.3 Water quality aspects for bank filtration in India 15 2.5.4 Risks to riverbank filtration sites from floods 16 2.6 Hypotheses favouring the use of bank filtration and the need for a concept to investigate potential RBF sites in India 17 3 Study areas 18 3.1 Choice of study areas 18 3.2 Case study site Haridwar 19 3.3 Case study site Patna 20 3.4 Case study site Srinagar in Uttarakhand 21 3.5 Hypotheses favouring RBF at the selected study sites 22 4 Methodology for the investigation of the case study sites 24 4.1 Overview of methodology for investigating the case-study sites 24 4.2 Investigations at the case study site of Haridwar 25 4.2.1 Initial site-assessment 25 4.2.2 Basic site-survey and establishing monitoring infrastructure 26 4.2.2.1 Identification of specific locations for monitoring wells 26 4.2.2.2 Geodetic survey and inventory of existing on-site infrastructure 26 4.2.2.3 Construction of exploratory wells 27 4.2.3 Determination of hydrogeological parameters 27 4.2.3.1 Sediment analyses 27 4.2.3.2 Determination of hydraulic conductivity by pump tests on large-diameter wells 29 4.2.4 Water level and stable isotope measurements 30 4.2.4.1 Water level 30 4.2.4.2 Stable isotopes 31 4.2.5 Water quality monitoring 31 4.2.5.1 Initial investigations, screening and formulation of monitoring concept 31 4.2.5.2 Comprehensive and regular monitoring 2011 - 2013 33 4.3 Investigations at the case study site of Patna 34 4.3.1 Initial site-assessment, basic-site survey and monitoring 34 4.3.2 Sampling for water quality and isotope analyses 35 4.4 Investigations at the case study site of Srinagar in Uttarakhand 35 4.4.1 Basic site-survey and establishing monitoring infrastructure 35 4.4.1.1 Identification of a specific location for a new RBF well 35 4.4.1.2 Construction of production and monitoring wells and exploratory boreholes 37 4.4.2 Determination of hydrogeological parameters and monitoring 38 4.4.2.1 Sediment analyses and determination of hydraulic conductivity of the aquifer 38 4.4.3 Water quality monitoring 40 4.5 Column experiments to determine the removal of bacteriological indicators under field conditions 40 5 Characterisation of the RBF system in Haridwar 42 5.1 Site and design aspects 42 5.1.1 Location of RBF wells 42 5.1.2 Design of RBF wells 44 5.1.3 Quantity of drinking water produced by RBF 45 5.2 Aquifer characterisation 47 5.3 Numerical groundwater flow model of RBF well field in Haridwar 49 5.3.1 Model set-up 49 5.3.2 Model calibration 50 5.4 Origin of water and mean portion of bank filtrate abstracted by RBF wells 52 5.5 Water quality 53 5.6 Analysis of presence of thermotolerant coliforms in RBF wells 56 5.7 Impact of regulated Upper Ganga Canal on RBF wells on Pant Dweep 58 5.8 Summary of case study site Haridwar 60 5.8.1 Aspects related to water quality 60 5.8.2 Benefit of groundwater flow modelling 60 6 Evaluation of the potential for RBF in Patna 62 6.1 Physiography and hydrogeology 62 6.1.1 South Ganga Plain 62 6.1.2 Patna 63 6.2 Ground and surface water levels 65 6.3 Ganga River morphology 66 6.4 Water quality 67 6.5 Numerical groundwater flow model of case study site Patna 68 6.5.1 Model geometry and initial conditions 68 6.5.2 Boundary conditions 69 6.5.3 Steady-state flow modelling 70 6.6 Isotope analyses 71 6.7 Summary of case study site Patna 71 7 Evaluation of the potential for RBF in Srinagar 73 7.1 Drinking water production and overview of geomorphology 73 7.2 RBF site characterisation 74 7.2.1 Aquifer geometry and material 74 7.2.2 Water levels 75 7.2.3 Hydraulic conductivity 76 7.3 Numerical groundwater flow model of case study site Srinagar 77 7.3.1 Model geometry and calibration 77 7.3.2 Origin of bank filtrate and travel time 78 7.4 Water quality 79 7.5 Discussion and summary of case study site Srinagar 81 8 Assessment of risks from floods and insufficient sanitary measures to RBF wells in Haridwar and Srinagar 82 8.1 Flood-risk identification from field investigations 82 8.1.1 Description of an extreme flood event in Haridwar 82 8.1.2 Description of an extreme flood event in Srinagar 82 8.1.3 Summary of identifiable risks 83 8.2 Assessment of risks to RBF wells 84 8.2.1 Design of wells and direct contamination 84 8.2.2 Field investigations on the removal of bacteriological indicators 85 8.2.3 Removal of coliforms under field conditions by column experiments 87 8.3 Proposals to mitigate risks at RBF sites Haridwar and Srinagar 89 8.3.1 Operational and technical aspects for a general risk management plan 89 8.3.2 Health aspects for a general risk management plan 89 8.3.3 Criteria for flood protection measures of RBF wells 90 8.3.4 Sanitary sealing of RBF wells 90 9 Application of initial site-assessment to investigate other RBF sites in India 92 9.1 Hydrogeology and system-design 92 9.1.1 RBF systems for small and large-scale urban water supply 92 9.1.2 “Koop” well RBF systems for small-scale rural water supply 98 9.2 Water quality parameters 98 9.2.1 Removal of bacteriological indicators by RBF 98 9.2.2 Removal of dissolved organic carbon and organic micropollutants by RBF 101 9.2.3 Inorganic parameters 102 10 Conclusions, recommendations and propagation of RBF 105 10.1 Hydrogeological and system-design considerations 105 10.2 Aspects for improvement of the concept for RBF site investigations 106 10.3 Policy and planning aspects for the propagation of RBF in India 108 References 110 Annexes 121 / Riverbank filtration or bank filtration (RBF / BF) is a potential alternative to the direct abstraction and conventional treatment of surface water by virtue of the effective removal of pathogens, turbidity, suspended particles and organic substances. A comprehensive overview of existing RBF systems in India has been compiled for the first time. To systematically select and investigate new and existing potential RBF sites in India, a methodological concept was developed and tested at three sites along the Ganga River. The four stages of the concept are: initial site-assessment, basic site-survey, monitoring of water quality and quantity parameters and determination of aquifer parameters and numerical groundwater flow modelling. Suitable geohydraulic conditions for RBF (hydraulic conductivity: 10E-4 to 10E-3 m/s, aquifer thickness: 11 to 20 m) exist along the upper course of the Ganga (Haridwar and Srinagar). Due to the presence of fine sediment layers beneath the river bed along the Ganga’s lower course (Patna), river-aquifer interaction occurs during increased shear stress on the riverbed in monsoon. The portion of bank filtrate abstracted by the wells in Haridwar was determined from isotope analyses (Oxygen 18) and electrical conductivity measurements of river and well water and is up to 90% for wells located on an island and between the river and a canal. The results were confirmed by groundwater flow modelling. A high removal of E. coli (3.5 to 4.4 Log10 units) and turbidity (>2 Log10 units) was observed at the investigated sites. An E. coli removal of 3 Log10 units was observed for short travel times of 2 days. Higher coliform counts in some wells occur due to contamination from landside groundwater. During floods and intense rainfall events, contamination of RBF wells from direct entry of flood water, seepage of surface runoff into the well through leaky covers, fissures in the well-heads / caissons and in-appropriately sealed well-bases has to be considered. The application of the adapted investigation concept to 15 other sites in India showed that the low DOC concentrations in river water (0.9 to 3.0 mg/L) and well-water (0.4 to 2.3 mg/L) are favourable for the application of RBF. A 50% decrease of the high (pre-monsoon) DOC concentration was observed during monsoon in Delhi and Mathura. For the exploration of new RBF sites in hilly / mountainous areas, investigations of the aquifer thickness using geophysical methods, subsurface flow conditions in the alluvial deposits and the risk from floods should be conducted.:Abstract i (Seitenzahl / page number) Acknowledgements iii Table of contents v List of tables viii List of figures ix Abbreviations and symbols xi 1 Introduction 1 1.1 Problem description 1 1.2 Riverbank filtration and its potential in India 2 1.3 Motivation 3 1.4 Aims 4 2 Bank filtration in context to India’s water resources 5 2.1 Water budget of India and the Ganga River catchment 5 2.1.1 Water budget 5 2.1.2 The Ganga River catchment 6 2.2 Problems of surface water abstraction for drinking water production 8 2.2.1 Effect of low surface flows on the quantity of raw water abstraction 8 2.2.2 Effect of the monsoon on conventional drinking water treatment plants using directly abstracted surface water 9 2.2.3 Quality of surface water 10 2.2.4 Treatment of directly abstracted surface water for drinking 11 2.3 Sustainability issues of groundwater abstraction 11 2.4 Drinking water consumption in India 12 2.5 Bank filtration for water supply 14 2.5.1 Geohydraulic, siting and design aspects of bank filtration systems 14 2.5.2 Water quality aspects 15 2.5.3 Water quality aspects for bank filtration in India 15 2.5.4 Risks to riverbank filtration sites from floods 16 2.6 Hypotheses favouring the use of bank filtration and the need for a concept to investigate potential RBF sites in India 17 3 Study areas 18 3.1 Choice of study areas 18 3.2 Case study site Haridwar 19 3.3 Case study site Patna 20 3.4 Case study site Srinagar in Uttarakhand 21 3.5 Hypotheses favouring RBF at the selected study sites 22 4 Methodology for the investigation of the case study sites 24 4.1 Overview of methodology for investigating the case-study sites 24 4.2 Investigations at the case study site of Haridwar 25 4.2.1 Initial site-assessment 25 4.2.2 Basic site-survey and establishing monitoring infrastructure 26 4.2.2.1 Identification of specific locations for monitoring wells 26 4.2.2.2 Geodetic survey and inventory of existing on-site infrastructure 26 4.2.2.3 Construction of exploratory wells 27 4.2.3 Determination of hydrogeological parameters 27 4.2.3.1 Sediment analyses 27 4.2.3.2 Determination of hydraulic conductivity by pump tests on large-diameter wells 29 4.2.4 Water level and stable isotope measurements 30 4.2.4.1 Water level 30 4.2.4.2 Stable isotopes 31 4.2.5 Water quality monitoring 31 4.2.5.1 Initial investigations, screening and formulation of monitoring concept 31 4.2.5.2 Comprehensive and regular monitoring 2011 - 2013 33 4.3 Investigations at the case study site of Patna 34 4.3.1 Initial site-assessment, basic-site survey and monitoring 34 4.3.2 Sampling for water quality and isotope analyses 35 4.4 Investigations at the case study site of Srinagar in Uttarakhand 35 4.4.1 Basic site-survey and establishing monitoring infrastructure 35 4.4.1.1 Identification of a specific location for a new RBF well 35 4.4.1.2 Construction of production and monitoring wells and exploratory boreholes 37 4.4.2 Determination of hydrogeological parameters and monitoring 38 4.4.2.1 Sediment analyses and determination of hydraulic conductivity of the aquifer 38 4.4.3 Water quality monitoring 40 4.5 Column experiments to determine the removal of bacteriological indicators under field conditions 40 5 Characterisation of the RBF system in Haridwar 42 5.1 Site and design aspects 42 5.1.1 Location of RBF wells 42 5.1.2 Design of RBF wells 44 5.1.3 Quantity of drinking water produced by RBF 45 5.2 Aquifer characterisation 47 5.3 Numerical groundwater flow model of RBF well field in Haridwar 49 5.3.1 Model set-up 49 5.3.2 Model calibration 50 5.4 Origin of water and mean portion of bank filtrate abstracted by RBF wells 52 5.5 Water quality 53 5.6 Analysis of presence of thermotolerant coliforms in RBF wells 56 5.7 Impact of regulated Upper Ganga Canal on RBF wells on Pant Dweep 58 5.8 Summary of case study site Haridwar 60 5.8.1 Aspects related to water quality 60 5.8.2 Benefit of groundwater flow modelling 60 6 Evaluation of the potential for RBF in Patna 62 6.1 Physiography and hydrogeology 62 6.1.1 South Ganga Plain 62 6.1.2 Patna 63 6.2 Ground and surface water levels 65 6.3 Ganga River morphology 66 6.4 Water quality 67 6.5 Numerical groundwater flow model of case study site Patna 68 6.5.1 Model geometry and initial conditions 68 6.5.2 Boundary conditions 69 6.5.3 Steady-state flow modelling 70 6.6 Isotope analyses 71 6.7 Summary of case study site Patna 71 7 Evaluation of the potential for RBF in Srinagar 73 7.1 Drinking water production and overview of geomorphology 73 7.2 RBF site characterisation 74 7.2.1 Aquifer geometry and material 74 7.2.2 Water levels 75 7.2.3 Hydraulic conductivity 76 7.3 Numerical groundwater flow model of case study site Srinagar 77 7.3.1 Model geometry and calibration 77 7.3.2 Origin of bank filtrate and travel time 78 7.4 Water quality 79 7.5 Discussion and summary of case study site Srinagar 81 8 Assessment of risks from floods and insufficient sanitary measures to RBF wells in Haridwar and Srinagar 82 8.1 Flood-risk identification from field investigations 82 8.1.1 Description of an extreme flood event in Haridwar 82 8.1.2 Description of an extreme flood event in Srinagar 82 8.1.3 Summary of identifiable risks 83 8.2 Assessment of risks to RBF wells 84 8.2.1 Design of wells and direct contamination 84 8.2.2 Field investigations on the removal of bacteriological indicators 85 8.2.3 Removal of coliforms under field conditions by column experiments 87 8.3 Proposals to mitigate risks at RBF sites Haridwar and Srinagar 89 8.3.1 Operational and technical aspects for a general risk management plan 89 8.3.2 Health aspects for a general risk management plan 89 8.3.3 Criteria for flood protection measures of RBF wells 90 8.3.4 Sanitary sealing of RBF wells 90 9 Application of initial site-assessment to investigate other RBF sites in India 92 9.1 Hydrogeology and system-design 92 9.1.1 RBF systems for small and large-scale urban water supply 92 9.1.2 “Koop” well RBF systems for small-scale rural water supply 98 9.2 Water quality parameters 98 9.2.1 Removal of bacteriological indicators by RBF 98 9.2.2 Removal of dissolved organic carbon and organic micropollutants by RBF 101 9.2.3 Inorganic parameters 102 10 Conclusions, recommendations and propagation of RBF 105 10.1 Hydrogeological and system-design considerations 105 10.2 Aspects for improvement of the concept for RBF site investigations 106 10.3 Policy and planning aspects for the propagation of RBF in India 108 References 110 Annexes 121
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Impacts de l'écoulement souterrain sur la dégradation du pergélisol

de Grandpré, Isabelle 04 1900 (has links)
No description available.

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