East Valley Water District is located in San Bernardino, California which is approximately 50 miles east of Los Angeles. In order to meet future water demands, East Valley Water District plans to increase recharge activities in the forebay area of the San Bernardino groundwater basin and expand wellfield operations immediately downgradient. Three possible recharge and wellfield designs were under consideration with annual recharge rates increasing 10,000 to 20,000 acre-feet/year in the Santa Ana spreading basins. Approximately four to five new production wells pumping an equal quantity of groundwater have been proposed. A two-dimensional finite element groundwater flow model was constructed and calibrated to reproduce historical water level data for the year 1945. They calibrated model was applied to simulate the hydrologic effects of each of the three designs over a ten-year period.

Deformation of the western part of the Table Mountain Group rocks during the Cape Orogeny created a series of folds and associated fractures. The subsequent continental break-up of Gondwana led to the development of large fault systems. These exert a major influence on deep and shallow groundwater flow. There are 3 main types of structures that are investigated. The geological contacts between hydraulically different lithologies, the primary characteristics of the sediments comprising the main geological units and the secondary structures developed from the tectonic events. These inter-alia include lithological boundaries, bedding and conjugate joints and large faults. Compartmentalisation of the aquifers by lithological and fault boundaries are the main regional level controls on flow in the study area. Joints are important for local control of flow, but cumulatively exert a regional effect as well. These controls exert a strong 3 dimensional impact on flow patterns within the area. Geological cross sections and detailed fieldwork combined with the conceptual models proposed are used to determine groundwater flow and the extent of the flow constraints. There is heterogeneity in the fault characteristics whilst there isconsistence in the impermeable aquitards. These effect boundaries at the base of the aquifer, divide the aquifer into upper and lower units and cap the top of the aquifer. Using water level data, EC and pH an attempt is made to establish patterns created by structures, mainly faults. There appears to be some control of these shown by patterns seen on contour plots of the data. Understanding of the structures can significantly alter the way the available data could be interpreted. The integration of all available data into the conceptual model provides an effective research tool, which opens up further avenues for new approaches and methods for continued research in this area.

<p>The Table Mountain Group (TMG) Aquifer is the second largest aquifer system in South Africa, after dolomites. This aquifer has the potential to be a signinficant source of water for the people of the Western Cape. The occurrence of hot water springs in the TMG in relation with the main geological fault systems in SOuth Africa shows that deep flow systmes do exist. Little is known about these deep aquifer systems in South Africa (i.e. flow mechanisms). To close the above-mentioned knowledge gap, this study was initiated. The current study gave a review of some of the aspects that needs to be considered when distinguishing deep groundwater from shallow groundwater.</p>

<p>Understanding of Groundwater Dependent Ecosystems (GDEs) and their extent within the Table Mountain Group (TMG) aquifer is poor. To understand the dependence to basic ecological and hydrogeological concepts need explanation. The use of current literature aided in identification and classification. From the literature it has come clear that groundwater dependence centers around two issues, water source and water use determination. The use of Geographical Information System (GIS) showed its potential in proof of water sources. Rainfall data and a Digital Elevation Model (DEM) for the Uniondale area have been used to do watershed delineation, which is in line with locating GDEs on a landscape. Thus the conceptual approach should be a broad one that sets a basis for both investigation (scientific research) and institutional arrangements (management).</p>

This research proposes an Infrastructure to model complex systems for hydrological modeling. Currently, the three main hydrological packages are: i) SEAWAT (modeling groundwater flow); ii) HECRAS (modeling surface water flow); iii) HEC-HMS (modeling atmospheric water flow). Each of these models is self-contained and has a different timescale and simulation speed. Consequently, any integrated model will only run as fast as the slowest of the models. This makes it difficult to provide reliable and dynamic information on water levels and water availability for a given geographical region in a timely manner. The goal of this research is to facilitate the integration of multiple hydrological models from different hydrological packages by applying Electronic Design Automation (EDA) methodologies, including System Level Design (SLD) methodology, SystemC-AMS language, Python language and libraries (numpy, Statsmodels, and ctypes). The EDA methodology brings in the additional advantage of significantly improved simulation speed. The Infrastructure to Model Complex Systems applications is demonstrated using the following SEAWAT benchmark problems: i) Case 1; ii) Henry; iii) Elder problem. Simulation results from the aforementioned benchmarks are analyzed and discussed. Lastly, future research work is presented. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

This thesis presents a preliminary study on geochemical conditions within the Snapper Creek well field in Miami-Dade County, Florida. The study investigates the background groundwater chemistry within the Biscayne aquifer in order to provide information on the geochemical processes and water-rock interactions within the study site. In conjunction with hydraulic gradient information, major ion chemistry and deuterium and oxygen-18 data were used as environmental tracers to help describe the groundwater-surface water interactions between the well field and the Snapper Creek canal. Hydrologic data show there is potential for natural groundwater recharge from the canal within the shallow flow zone of the Biscayne aquifer and chemical data show evidence of canal-groundwater mixing within this zone. The limitations for the v environmental tracers employed within the study are addressed, as well as recommendations for further research involving natural geochemical tracers and groundwater-surface water interactions near municipal well fields. This study was part of a larger effort being conducted by the U.S. Geological Survey in order to assess municipal well field pumping effects on the Snapper Creek (C-2) canal. / by Dominick J. Antolino. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Escoamento de água subterrânea em meios porosos fraturados é um problema de grande importância, principalmente nos contextos de petróleo, energia geotérmica e repositórios geológicos. Com o aquecimento da Terra, a geração de energia com baixa emissão de gases estufa torna-se imperativa, considerando o crescimento de uso de energia e o impacto do aquecimento global. Dentre as opções disponíveis para geração de energia, a energia nuclear apresenta-se como candidata. Entretanto, dentre os riscos do uso de energia nuclear, o destino do combustível usado e de materiais provenientes de descomissionamento é um problema em aberto. Repositórios geológicos surgem como uma alternativa para a estocagem de médio e longo prazo, por serem capazes de proporcionar isolamento em escalas geológicas de tempo. O principal vetor de propagação do material radioativo estocados em repositórios é a água subterrânea, e meios fraturados estão presentes na maioria dos domínios. Fraturas podem propagar a água subterrânea e, portanto, solutos com velocidades muito maiores que as do meio poroso. Além disso, fraturas são, geralmente, sistemas multiescala, em que diferentes escalas - de centímetros a kilômetros - podem ter um papel significativo. Métodos como elementos finitos, apesar de representarem certos comportamentos do escoamento em fraturas, têm dificuldade em simular sistemas com grandes diferenças de escala, já que necessitam de discretização do domínio. O Método de Elementos Analíticos (MEA) surge como uma alternativa a esse problema, pois não necessita de discretização de domínio, podendo simular características hidrogeológicas em diferentes escalas. Este trabalho tem como proposta aperfeiçoar o MEA, desenvolvendo um elemento analítico para fraturas que interagem com o meio poroso, aplicando os desenvolvimentos recentes na teoria do Método. Baseado na Integral de Cauchy e em transformações de coordenadas, o novo formalismo de solução no plano permite maior precisão na imposição das condições de contorno, sendo aplicado para inomogeneidades circulares, inomogeneidades poligonais formadas por line doublets e para o elemento de fratura. Dificuldades numéricas na simulação para fraturas levaram ao desenvolvimento de um método matricial de solução, aplicado com sucesso para todos os elementos apresentados neste trabalho. Soluções exatas para a inomogeneidade circular e para uma fratura foram comparadas com inomogeneidades poligonais equivalentes, com sucesso. O método matricial permitiu também um estudo da convergência do método iterativo e possibilita a melhoria do Método de Elementos Analíticos em geral. / Groundwater flow in fractured porous media is a recent and modern problem, considering the petroil, geothermic energy and geologic repositories context. As the Earth warms, low \'CO IND.2\' energy generation is paramount, when the projections of energy demand and worsening of the global warming effects are factored in. Nuclear energy generation appears as one of the canditates to generate electricity with low \'CO IND.2\' emissions. Several factors must be considered, thought, when nuclear energy is concerned. The spent nuclear fueld and the decomission residues must be safely stored for long periods of time. One of the alternatives for mid and long term disposal is the use of geological repositories. Because of its characteristics, groundwater studies must be conducted to assert the safety of the repositories, as its the main contaminant vector for the stored nuclear material. Fractures must be considered in those studies, as they are usually present in almost all settings considered for repositories, and can propagate groundwater (and dissolved solutes) with very high speeds, several orders of magnitude faster than the porous media. Fractures also forms multiscale problems, where different problem scales - from centimeters to kilometers - can influence the behavior of the groundwater flow and the consequent solute transport. The usual groundwater simulation methods, even when capable of including fracture phenomena, have problems with the scale differences, as they usually depend on domain discretization. The Analytic Element Method is based on analytic solutions of the groundwater governing equations and does not depend on domain discretization, being able to tackle multiscale problems that the other methods cant produce a feasible solution. The Analytic Element Method has been developed in recent years and has been applied in different fields, as wellhead protection area delineation. This work proposes to improve the Analytic Elemento Method developing an analytic element for flow in fractures, using the recent developments as the direct use of Cauchy Integrals in the plane. These new developments allow increased precision on the numerical boundary conditions matching. This method is applied on circular inhomogeneities, polygonal inhomogeneities modelled by line doublets and the fracture element. Numerical problems in the boundary condition matching for the fractures led to the development of matrix solution method, used on all elements presented in this work. Exact solutions for one circular inhomogeneity and for one fracture allowed comparison with the numerical ones, with satisfactory results. The matrix method also permitted a convergence study of the iterative methods, possibilitating for the general improvement of the Analytic Element Method.

Intercommunication has been identified between the unconfined and uppermost confined aquifer systems underlying a portion of the U.S. Department of Energy's Hanford Site. Erosional thinning and fracturing of the basalt confining layer within the study area allows physical contact between the two aquifers, but the vertical hydraulic gradient (a required driving force) is small. To better conceptualize the distribution and volume of the leakage occurring between the aquifer systems, this study investigates the confined Rattlesnake Ridge Aquifer flow system, which appears to be more sensitive to the vertical leakage than the overlying unconfined aquifer.

Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable. One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have been shown to be stable and numerically robust for advection-dominated transport in heterogeneous velocity fields. However, the existing finite analytic methods for solute transport in multiple dimensions have the following disadvantages. First, the method is computationally inefficient when applied to heterogeneous media due to the complexity of the formulation. Second, the evaluation of finite analytic coefficients is when the Peclet number is large. Third, the method introduces significant numerical diffusion due to inadequate temporal approximation when applied to transient problems. This thesis develops improved finite analytic methods for two-dimensional steady as well as unsteady solute transports in steady velocity fields. For steady transport, the new method exploits the advantages of the existing finite analytic and finite difference methods. The analytically difficult diffusion terms are approximated by finite difference and numerically difficult advection and reaction terms are treated analytically in a local element in deriving the numerical schemes. The new finite analytic method is extended to unsteady transport through application of Laplace transformation. Laplace transformation converts the transient equation to a steady-state expression that can be solved with the steady version of the improved finite analytic method. Numerical inversion of the transformed variables is used to recover solute concentration in the physical space-time domain. The effectiveness and accuracy of the new finite analytic method is demonstrated through stringent test examples of two dimensional steady-state transport in highly variable velocity fields. The results clearly demonstrated that the improved finite analytic methods are efficient, robust and accurate.

Graduation date: 1999