Semi-analytical methods for simulating the groundwater-surface water interface

Groundwater-surface water interaction is a key component of the hydrologic cycle. This interaction plays a key role in many environmental issues such as the impacts of land use and climate change on water availability and water quality. Modeling of local and regional groundwater-surface water interactions improves understanding of these environmental issues and assists in addressing them. Because of the physical and mathematical complexities of this interaction, numerical approaches are generally used to model water exchange between subsurface and surface domains. The efficiency, accuracy, and stability of mesh-based numerical models, however, depend upon the resolution of the underlying grid or mesh. Grid-free analytical methods can provide fast, accurate, continuous and differentiable solutions to groundwater-surface water interaction problems. These solutions exactly satisfy mass balance in the entire internal domain and may improve our understanding of groundwater-surface water interaction principles. However, to model this interaction, analytical approaches typically required simplifying, sometimes unrealistic, assumptions. They are typically used to implement linearized mathematical models in homogenous confined or semi-confined aquifers with geometrically regular domains. By benefiting from the strengths of both analytical and numerical approaches, grid-free semi-analytical methods may be able to address more challenging groundwater problems which have been out of reach of traditional analytical approaches, and/or are poorly simulated using mesh-based numerical methods. Here, novel 2-D and 3-D semi-analytical solutions for the simulation of mathematically and physically complex groundwater-surface water interaction problems are developed, assessed and applied. Those models are based upon the series solution method and analytic element method (AEM) and are intended to address groundwater-surface water interactions induced by pumping wells and/or the presence of surface water bodies in naturally complex stratified unconfined aquifers. Semi-analytical solutions are obtained using the least squares method, which is used to determine the unknown coefficients in the series expansion and the unknown strengths of analytic elements. The series and AEM solutions automatically satisfy the groundwater governing equation. Hence, the resulting solutions are exact over the entire domain except along boundaries and layer interfaces where boundary and continuity conditions are met with high precision. A robust iterative algorithm is used to implement a free boundary condition along the phreatic surface with a priori unknown location. This thesis addresses three general problem types never addressed within a semi-analytic framework. First, a steady-state free boundary semi-analytical series solutions model is developed to simulate 2-D saturated-unsaturated flow in geometrically complex stratified unconfined aquifers. The saturated-unsaturated flow is controlled by water exchange along the land surface (e.g., evapotranspiration and infiltration) and the presence of surface water bodies. The water table and capillary fringe are allowed to intersect stratigraphic interfaces. The capillary fringe zone, unsaturated zone, groundwater zone and their interactions are incorporated with a high degree of accuracy. This model is used to assess the influences of important factors on unsaturated flow behavior and the water table elevation. Second, a 3-D free boundary semi-analytical series solution model is developed to simulate groundwater-surface water interaction controlled by infiltration, seepage faces and surface water bodies along the land surface. This model can simulate the water exchange between groundwater and surface water in geometrically complex stratified phreatic (unconfined) aquifers. The a priori unknown phreatic surface will be obtained iteratively while the locations of seepage faces don’t have to be known a priori (i.e., this is a constrained free boundary problem). This accurate grid-free multi-layer model is here used to investigate the impact of the sediment layer geometry and properties on lake-aquifer interaction. Using this method, the efficiency of widely-used Dupuit-Forchheimer approximation used in regional groundwater-surface water interaction models is also assessed. Lastly, this 3-D groundwater-surface water interaction model is augmented with AEM solutions to simulate horizontal pumping wells (radial collector well) for assessing surface water impacted by pumping and determining the source of extracted well water. The resulting model will be used to assess controlling parameters on the design of a radial collector well in a river bank filtration system. This 3-D Series-AEM model, in addition, mitigates the limitations of AEM in modeling of general 3-D groundwater-surface water interaction problems

Advancing the use of geographic information systems, numerical and physical models for the planning of managed aquifer recharge schemes

Global change is a major threat to local groundwater resources. Climate change and population growth are factors that directly or indirectly augment the increasing uptake of groundwater resources. To outbalance the pressure on aquifers, managed aquifer recharge (MAR) schemes are increasingly being implemented. They enable the subsurface storage of surplus water for times of high demand. The complexity of MAR schemes makes their planning and implementation multifaceted and requires a comprehensive assessment of the local hydrogeological and hydrogeochemical conditions. Despite the fact that MAR is a widely used technique, its implementation is not well regulated and comprehensive planning and design guidelines are rare. The use of supporting tools, such as numerical and physical models or geographic information systems (GIS), is rising for MAR planning but their scope and requirements for application are rarely reflected in the available MAR guidelines. To depict the application potential and the advantages and disadvantages of the tools for surface infiltration MAR planning, this thesis comprises reviews on the past use of the tools as well as suggestions to improve their applicability for MAR planning. GIS is not mentioned by most MAR guidelines as a planning tool even though it is increasingly being used for MAR mapping. Through a review of GIS-based MAR suitability studies, this thesis shows that the MAR mapping process could be standardized by using the often-applied approach of constraint mapping, suitability mapping by using pairwise comparison for weight assignment and weighted linear combination as a decision rule, and a subsequent sensitivity analysis. Standardizing the methodology would increase the reliability and comparability of MAR maps due to the common methodological approach. Thus, the proposed standard methodology was incorporated into a web GIS that simplifies MAR mapping through a pre-defined workflow. Numerical models are widely used for the assessment of MAR schemes and are included into some MAR planning guidelines. However, only a few studies were found that utilized vadose zone models for the planning and design of MAR schemes. In this thesis, a review and a subsequent case study highlight that numerical modelling has many assets, such as monitoring network design or infiltration scenario planning, that make its utilization during the MAR planning phase worthwhile. Consequently, this study advocates the use of vadose zone models for MAR planning by showing their potential areas of application as well as their uncertainties that need to be regarded carefully during modelling. Physical models used for MAR planning are typically field or pilot sites, as some MAR legislation requests pilot sites as part of the preliminary assessment. Laboratory experiments are used less often and are mostly restricted to the analysis of very specific issues, such as clogging. This thesis takes on the issue of scaling laboratory results to the field scale by comparing results from three physical models of different scales and dimensionality. The results indicate that preferential flow paths, air entrapment and boundary influence limit the quantitative validity of laboratory experiments. The use of 3D tanks instead of 1D soil columns and the application of statistical indicators are means to increase the representativeness of laboratory measurements. Nevertheless, physical models have the potential to improve MAR planning in terms of detailed process assessment, scenario and sensitivity analyses. All tools discussed in this thesis have their merits for MAR scheme planning and should be advocated better in MAR guidelines by depicting their application potential, advantages and disadvantages. The information accumulated in this thesis is a step towards an advanced use of supporting tools for the planning and design of MAR schemes.:1 Introduction 1.1 Motivation 1.2 Objectives 1.3 Structure of the thesis 2 Status quo of the planning process of MAR schemes 2.1 Guidance documents on general MAR planning 2.2 Application of GIS, numerical and physical models for MAR planning 2.3 Planning of surface infiltration schemes 3 Using GIS for the planning of MAR schemes 3.1 Implications from GIS-MCDA studies for MAR mapping 3.2 Development of web tools for MAR suitability mapping 4 Using numerical models for the planning of MAR schemes 4.1 Review on the use of numerical models for the design and optimization of MAR schemes 4.2 Planning a small-scale MAR scheme through vadose zone modelling 5 Using physical models for the planning of MAR schemes 5.1 Design of the experimental study 5.2 Comparison of three different physical models for MAR planning 6 Discussion and research perspectives 7 Bibliography 8 AppendixDer globale Wandel stellt eine große Bedrohung für die lokalen Grundwasserressourcen dar. Klimawandel und Bevölkerungswachstum sind Faktoren, die, direkt oder indirekt, die zunehmende Nutzung von Grundwasserressourcen verstärken. Um diesen Druck auf die Grundwasserleiter auszugleichen, werden verstärkt Maßnahmen zur gezielten Grundwasserneubildung (managed aquifer recharge = MAR) durchgeführt. Dies ermöglicht die unterirdische Speicherung von überschüssigem Wasser für Zeiten hohen Bedarfs. Die Komplexität von MAR-Anlagen macht ihre Planung und Umsetzung kompliziert und erfordert eine umfassende Bewertung der lokalen hydrogeologischen und hydrogeochemischen Bedingungen. Trotz der weltweiten Implementierung von MAR ist dessen Planung wenig reguliert. Umfassende Planungs- und Gestaltungsrichtlinien sind rar. Der Einsatz unterstützender Werkzeuge, wie numerischer und physikalischer Modelle oder Geoinformationssysteme (GIS), nimmt bei der MAR-Planung zu, aber ihre Einsatzmöglichkeiten und ihre Anforderungen an die Anwendung spiegeln sich selten in den verfügbaren MAR-Richtlinien wider. Um das Anwendungspotential und die Vor- und Nachteile der Werkzeuge für die MAR-Planung darzustellen, wurden für diese Arbeit Recherchen über den bisherigen Einsatz der Werkzeuge durchgeführt. Zusätzlich wurden Vorschläge zur Erhöhung ihrer Anwendbarkeit für die MAR Planung gemacht. Der Schwerpunkt lag dabei auf Oberflächeninfiltrationsverfahren. GIS wird in keiner MAR-Richtlinie als Planungsinstrument erwähnt, obwohl es zunehmend für die MAR-Kartierung eingesetzt wird. Eine Recherche über GIS-basierte MAR-Eignungsstudien zeigte, dass der MAR-Kartierungsprozess standardisiert werden kann mittels des oft genutzten Ansatzes: initiales Ausschneiden von Gebieten, welche Restriktionen unterliegen, dem folgend die Eignungskartierung mittels Paarvergleich für die Wichtung der GIS-Karten und der gewichteten Linearkombination als Entscheidungsregel, sowie eine abschließende Sensitivitätsanalyse. Die Standardisierung der Methodik könnte die Zuverlässigkeit und Vergleichbarkeit von MAR-Karten aufgrund des gemeinsamen methodischen Ansatzes erhöhen. Daher wurde die standardisierte Methodik in ein Web-GIS integriert, das über einen definierten Workflow die MAR-Kartierung vereinfacht. Numerische Modelle werden häufig für die Beurteilung von MAR-Systemen verwendet und sind in einigen MAR-Planungsrichtlinien ausgewiesen. Es wurden jedoch nur wenige Studien gefunden, die die Modelle der ungesättigten Zone für die Planung und Gestaltung von MAR Standorten verwendeten. Die in dieser Arbeit durchgeführte Literaturrecherche und eine darauf aufbauende Fallstudie zeigen, dass die numerische Modellierung viele Vorteile bietet, wie z. B. beim Design eines Monitoring-Netzwerkes oder bei der Planung von Infiltrationsszenarien. Physikalische Modelle, die für die MAR-Planung verwendet werden, sind meist Feld- oder Pilotversuche, da einige MAR-Gesetzgebungen Pilotstandorte im Rahmen der Vorabbewertung verlangen. Laborexperimente werden seltener eingesetzt und beschränken sich meist auf die Analyse sehr spezifischer Fragestellungen, wie z.B. der Kolmatierung. Diese Arbeit beschäftigt sich mit der Skalierbarkeit von Laborergebnissen auf die Feldskale, indem sie Ergebnisse aus drei physikalischen Modellen verschiedener Maßstäbe und Dimensionen vergleicht. Die Ergebnisse deuten darauf hin, dass Makroporen, Lufteinschlüsse und der Einfluss der Randbedingungen die quantitative Aussagekraft von Laborversuchen einschränken. Der Einsatz von 3D-Tanks anstelle von 1D-Bodensäulen oder von statistischen Indikatoren ist ein Mittel zur Erhöhung der Repräsentativität von Labormessungen. Nichtsdestotrotz hat die Anwendung physikalischerModelle das Potenzial, die MAR-Planung in Bezug auf detaillierte Prozessbewertung, Szenarien und Sensitivitätsanalysen zu unterstützen. Alle beschriebenen Instrumente haben ihre Vorzüge bei der Bewertung von MAR-Anlagen und sollten in MAR-Richtlinien detaillierter berücksichtigt werden, indem ihr Anwendungspotenzial, ihre Vor- und ihre Nachteile dargestellt werden. Die für diese Arbeit zusammengestellten Informationen sind ein Schritt zur Förderung der beschriebenen Planungsinstrumente für die Planung und Gestaltung von MAR-Anlagen.:1 Introduction 1.1 Motivation 1.2 Objectives 1.3 Structure of the thesis 2 Status quo of the planning process of MAR schemes 2.1 Guidance documents on general MAR planning 2.2 Application of GIS, numerical and physical models for MAR planning 2.3 Planning of surface infiltration schemes 3 Using GIS for the planning of MAR schemes 3.1 Implications from GIS-MCDA studies for MAR mapping 3.2 Development of web tools for MAR suitability mapping 4 Using numerical models for the planning of MAR schemes 4.1 Review on the use of numerical models for the design and optimization of MAR schemes 4.2 Planning a small-scale MAR scheme through vadose zone modelling 5 Using physical models for the planning of MAR schemes 5.1 Design of the experimental study 5.2 Comparison of three different physical models for MAR planning 6 Discussion and research perspectives 7 Bibliography 8 Appendi

New Insight into Brucella Infection and Foodborne Diseases

Brucellosis is an important zoonotic disease. More than half a million new cases from 100 countries are reported annually to the World Health Organization (WHO). The majority of patients are living in developing countries. Brucellosis is a systemic infection with a broad clinical spectrum, ranging from an asymptomatic disease to a severe and fatal illness. Clinical and laboratory features vary widely. The main presentations are acute febrile illness, localized infection, and chronic infection. Laboratory tools for diagnosis of brucellosis include culture, serology, and polymerase chain reaction (PCR). The goal of brucellosis therapy is to control the illness and prevent complications, relapses, and sequelae. Important principles of brucellosis treatment include use of antibiotics with activity in the acidic intracellular environment, use of combination regimens, and prolonged duration of treatment. This book is the result of several months of outstanding efforts by the authors and the revision of the content by experts in the field of brucellosis. This book is a valid resource and is intended for everyone interested in infectious disease to learn the most important aspects of brucellosis

Design and Optimization of a Fully-Penetrating Riverbank Filtration Well Scheme at a Fully-Penetrating River Based on Analytical Methods

In order to maintain the sustainable development of pumping wells in riverbank filtration (RBF) and simultaneously minimize the possible negative effects induced, it is vital to design and subsequently optimize the engineering parameters scientifically. An optimizing method named Five-Step Optimizing Method was established by using analytic methods (Mirror-Image Method, Dupuit Equation and the Interference Well Group Method, etc.) systematically in this study considering both the maximum allowable drawdown of the groundwater level and the water demand as the constraint conditions, followed by a case study along the Songhua River of northeast China. It contained three parameters (number of wells, distance between wells, and distance between well and river) for optimizing in the method, in which the well type, depth and radius were beforehand designed and fixed, without the need of optimizing. The interference between wells was found to be a decisive factor that significantly impacts the optimizing effort of all the three parameters. The distance between the well and the river was another decisive factor impacting the recharge from the river and subsequently, the well water yield. There would be more than one optional scheme sometimes in the optimized result, while it’s not yet difficult in practice to single out the optimal one considering both the field setting and the water demand. The established method proved to be applicable in the case study

Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context

"Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context is based on the work from the Saph Pani project (Hindi word meaning potable water). The book aims to study and improve natural water treatment systems, such as River Bank Filtration (RBF), Managed Aquifer Recharge (MAR), and wetlands in India, building local and European expertise in this field. The project aims to enhance water resources and water supply, particularly in water stressed urban and peri urban areas in different parts of the Indian sub-continent. This project is co-funded by the European Union under the Seventh Framework (FP7) scheme of small or medium scale focused research projects for specific cooperation actions (SICA) dedicated to international cooperation partner countries. Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context provides: an introduction to the concepts of natural water treatment systems (MAR, RBF, wetlands) at national and international level knowledge of the basics of MAR, RBF and wetlands, methods and hydrogeological characterisation an insight into case studies in India and abroad. This book is a useful resource for teaching at Post Graduate level, for research and professional reference.

Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context

"Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context is based on the work from the Saph Pani project (Hindi word meaning potable water). The book aims to study and improve natural water treatment systems, such as River Bank Filtration (RBF), Managed Aquifer Recharge (MAR), and wetlands in India, building local and European expertise in this field. The project aims to enhance water resources and water supply, particularly in water stressed urban and peri urban areas in different parts of the Indian sub-continent. This project is co-funded by the European Union under the Seventh Framework (FP7) scheme of small or medium scale focused research projects for specific cooperation actions (SICA) dedicated to international cooperation partner countries. Natural Water Treatment Systems for Safe and Sustainable Water Supply in the Indian Context provides: an introduction to the concepts of natural water treatment systems (MAR, RBF, wetlands) at national and international level knowledge of the basics of MAR, RBF and wetlands, methods and hydrogeological characterisation an insight into case studies in India and abroad. This book is a useful resource for teaching at Post Graduate level, for research and professional reference.

River Ecological Restoration and Groundwater Artificial Recharge

Three of the eleven papers focused on groundwater recharge and its impacts on the groundwater regime, in which recharge was caused by riverbed leakage from river ecological restoration (artificial water replenishment). The issues of the hydrogeological parameters involved (such as the influence radius) were also reconsidered. Six papers focused on the impact of river ecological replenishment and other human activities on river and watershed ecology, and on groundwater quality and use function. The issues of ecological security at the watershed scale and deterioration of groundwater quality were of particular concern. Two papers focused on water resources carrying capacity and water resources reallocation at the regional scale, in the context of the fact that ecological water demand has been a significant topic of concern. The use of unconventional water resources such as brackish water has been emphasized in the research in this issue

Kinetic and Friction Head Loss Impacts on Horizontal Water Supply and Aquifer Storage and Recovery Wells

Groundwater wells can have extreme pressure buildup when injecting and extreme pressure drawdown when extracting. Greater wellbore contact with the aquifer minimizes pressure buildup and pressure drawdown. Aquifers are usually much more laterally extensive than vertically thick. Therefore, horizontal wells can be longer than vertical wells thus increasing aquifer contact and minimizing pressure issues. The length and therefore the effectiveness of horizontal wells are limited by two factors, either well construction or intra-wellbore head loss. Currently no analytical groundwater model rigorously accounts for intra-wellbore kinetic and friction head loss. We have developed a semi-analytical, intra-wellbore head loss model dynamically linked to an aquifer. This model is the first of its kind in the groundwater literature. We also derived several new boundary condition solutions that are rapidly convergent at all times. These new aquifer solutions do not require approximation or pressure pulse tracking. We verified our intra-wellbore head loss model against MODFLOW-CFP and found matches of three significant figures. We then completed 360 simulations to investigate intra-wellbore head loss. We found that only when aquifer drawdown was small will intra-wellbore head loss be relatively important. We found intra-wellbore head loss is relatively important only in extreme scenarios. We also found that kinetic head loss was greater than friction head loss if the well was less than 10m – 100m long. To investigate well construction limitations, we developed an equation for the optimal slant rig entry angle, a drilling forces model, and a well construction cost model. We then collected well cost data and combined these models to make 60 well cost estimates. We found the relative cost of a horizontal well, compared to a vertical well, decreases with depth. We then used our aquifer model to investigate the benefits of horizontal wells. We found several parameters that increase the number of vertical wells replaced by a horizontal well. These parameters include less time since pumping began, nearby recharge boundaries, vertical fractures, lower permeability, higher specific storativity, and thinner aquifers. Comparing horizontal well benefit with cost, we found that horizontal wells may or may not be economically advantageous depending on site specific conditions