GROUNDWATER

Author: LOZANO TOMAS EDURNE.
Year: 2003.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: UPC.
Place of preparation: ENGINYERIA DEL TERRENY, CARTOGRÁFICA I GEOFÍSICA.

Summary: The study area, known as The Cotos, is located in the NDP, in the OS of Spain, occupying parts of the provinces of Huelva and Seville. It is noteworthy that there is a cord in the coastal dunes cohabiting shifting sand dunes and stable as well as the emergence of numerous loopholes interdunares nature groundwater in topographical depressions. One objective of this thesis is to improve and advance the knowledge of hydrogeological factors which determine the functioning of the wetlands. It has carried out a review of the conceptual model of groundwater flow, a detailed appreciation of the flow of groundwater within the gaps, and chemical and isotopic characterization of the groundwater and surface to identify processes modifying their chemical and isotopic composition. Another objective is to try to assess the real situation of the area in terms of the potential impacts on groundwater and surface water withdrawals by changing the environment, land use and recharge in the area. To this has pasmado all information in a preliminary numerical model, as an auxiliary tool for conducting an initial assessment of these impacts. After further study and deep, and in the light of the new data obtained from recent drilling, the geological model parala Cotos The area is established as follows: 1, High-Unit, uniform, consisting of fine sand or socks, with some subordinate levels of sandy clay but little lateral continuity. 2-Intermediate Unit, composed for gray clay, with subordinate levels of sand, gravel and limestone travertínicas (in the north); presents its maximum power within the ecotone and is issuing to the OR to zero in Abalario. 3, Lower-Unit, very heterogeneous, composed of fine sand, medium or coarse, gravel and gravel, with subordinate levels of clay, sandy clay and shells in the area of Los Cotos becomes gritty and is separate from the Superior Unit the wedge arcillos (Intermediate Unit). 4, Basal-Unit, composed of sandy clay and sand finas-medias with abundant levels of shells, are considered the basis of the geological model and system cuífero. The hydrogeological model is reduced to two units aquifer (Unity higher and lower unit), with different transmisividades separated by a clay layer serving as confining respect to the Lower Unit. In Unit Senior flow of groundwater occurs dominantemente of vertically Locally produced discharges of groundwater in topographical depressions where reaches the water surface and leads to lagoons whose waters are subject to evaporation surface . The groundwater may be affected by the processes of evaporation groundwater or evapotranspiration from plants. In the environment of the gaps are formed different flow systems at regional and local levels depending on the time of year (dry or wet), the flood level of the lagoon and the position of the groundwater level. The results can be seen as a sensitivity analysis imposed by different wings or model such as changes in the set of drawings of the study area in land use and recharging. The system has not been stabilized in the period simulated 22 years, snipe periods buffer (for the 50% change in level) between 24 and 13 years.

Author: IBÁÑEZ SANDRA PATRICIA.
Year: 2004.
University: GRANADA [www.ugr.es].
Place of defense: UNIVERSIDAD DE GRANADA.
Place of preparation: INSTITUTO DEL AGUA-DEPARTAMENTO GEODINÁMICA.

Summary: The coastal aquifers the particular feature of the existence of a body of salt water in unao the limits of the aquifer. In the vicinity of the contact mar-acuífero there is a dynamic equilibrium of forces, extremely fragile governing phenomena of trade and transportation between the masses of salt water from the sea and the freshwater aquifer. The salt water because of their greater density, freshwater moves upwards and enters the aquifer a distance determined by the particular value of the levels of water in the aquifer and in the sea, and by the particular differences of density. It forms the saline wedge. The models used to study this contact between freshwater and saltwater are classified in net interface models or models coupled mass transit. Net interface models consider freshwater and saltwater are immiscible fluids, these models provide only an approximation of the correct position of freshwater and seawater when the mixing zone is a few meters. The mass transport models that are used in marine intrusion, in contrast to net interface models, consider that freshwater and saltwater can be mixed and they take intoaccount the effects of the flux density on the move, why they are called variable density models. The transport models mass density variable solucionana equations of state to link the concentration of solutes with the density of the fluid (Oude Essink, 2003c). The difficulty most important inthe application of these models are presented in the calibration stage, as it involves the simultaneous adjustment and resolution of a model for flow and other transportation. In mass, in addition to the shortage of field data necessary to describe the density matrix and variable conditions studied edge of the aquifer, which usually determines the transport models of mass density variables not applied frequently. Reserving some special cases to investigate the most relevant findings of a study in a section (Zhent and Bennett 1995), we use the models instead of constant density. The models constant density not introduce changes in the equation of motion equations inthe water because of the density, as this is considered constant over time and space. Accordingly equations flow of transport and mass are resolved independently from one another. For all these reasons, this Doctoral Thesis, had as a main goal to establish a simple methodology, combining the use of both types of modlos to simplify the problems that arise in the process of calibration (working on the Green River aquifer), and the second goal most important was to apply this methodology to study the aquifer coastal Motril-Salobreña to analyze the current state of the position of the wedge and predecri the future effects it is likely to introduce the launch of the Press Rules on the hydrodynamics of karma hydrochemistry aquifer. In general, the proposed methodology emphasizes the importance of working first with a constant density model to achieve a pre-calibaración the parameters of flow, this calibration will be closer to the end, developed with the method of density varible, in the measure that the aquifer is not affected by this process instrusiÂ'pon marina. With respect to the analysis of aquifer Motril-Salobreña can say that at present this cauífero has no navy and that the position of the wedge at depths greater than 200 meters does not exceed 1100 m from the coast. This balance is romporá when it starts to operate the dam Rules, and if the conditions are suitable management wedge advance about 500m to its new position of balance. However, if the management of resources is not adequate, given the nature of the geometry of the aquifer that has a large surface of contact with the sea, and considering that most of the volume of the aquifer and found p 8 or debaj 324 or height of the sea, there is a risk of destabilizing the system and produce significant pollution intrusion.

Author: LAZARIM HELIO ALEXANDRE.
Year: 2005.
University: POLITÉCNICA DE MADRID [www.upm.es].
Place of defense: E.T.S.DE ING. DE MINAS DE MADRID.
Place of preparation: ESCUELA TÉCNICA SUPERIOR DE INGENIEROS DE MINAS DE MADRID.

Summary: STUDY PORPONE THE ACTIONS AIMED AT THE CLOSING OF IRON MINES TO OPEN SKY, TAKING AS AN EXAMPLE THE MINE N4E, HUBICADA IN THE REGION OF THE JUNGLE AMAZÓNICA BRASILEÑA. WHO WILL BE THE CLOSING OF A REINTEGRATION AREA TO EXISTING IN THE NATURE AROUND, THROUGH ACTIVIADES OF REVEGETACIÓN AND FORMATION OF A LAKE. FOR THE FORMATION OF THE LAKE IS I HAVE ONE TYPE MIFIM CAPAZ MODELING OF SIMULAR METHOD TRONCOCONICA OF SHORT TERM TO OPEN SKY. THE SOCIO-ECONOMIC ISSUES CONSIDERED BY EMPLOYEES OF THE MINE VAN TO WORK IN OTHER MINES TO BE EXPLOTADAS AFTER THE END OF N4E.

Author: DE LA ORDEN GOMEZ JOSÉ ANTONIO.
Year: 2005.
University: POLITÉCNICA DE MADRID [www.upm.es].
Place of defense: E.T.S. DE ING. DE MINAS DE MADRID..
Place of preparation: E.T.S. DE ING. DE MINAS DE MADRID..

Summary: The thesis deals with the complicated process of managing water resources in a watershed located in the small lift Spanish, in particular river basin Girona in the north of the province of Alicante, where the potential for regulation of surface same is virtually zero, mainly because of topographical constraints on type. The management proposal in this doctoral work is based on the principle of joint use of surface water and groundwater, which is one of the basic drivers of water policy in Spain and, as such, is reflected in text current force of the Water Act. Specifically, it proposes to use artificial recharge of aquifers, one of the techniques used in the schedules of use using whole, as a basic element for a better use of water resources of the basin and to achieve a greater degree of satisfying the demands of water in the area, both in quantity and quality. This artificial recharge is currently in the Unit Hidrogeológica 08.38, Plana of Gandía-Denia, especially in a sector of the same covering the municipalities of Vergel and Els Poblets, in Alicante. This sector of the unit is the subject of this thesis study, in terms of groundwater resources, while the object extends to the rest of the river basin Gerona when it comes to resources and the evaluation of surface resources available. The thesis proposes the design and operation of an installation of artificial recharge industry-wide throughout the river basin Girona, extending the current recharge installation and expanding its current boundaries to cover the entire river basin, forming this way an approach to water management ambitious and comprehensive to avoid problems arising from water shortages at certain times of year. First, it performs a detailed study of the aquifer, with an emphasis on their geological and hydrogeological conditions, demarcation of their boundaries and description of the problem that suffers. There has also been an exhaustive inventory of items aquifers in the area Vergel-Els Poblets, and a detailed review of all the existing hydraulic infrastructure in the river basin Girona. Here is a review of the historical experiences of artificial recharge that began to take place in the aquifer in the eighties, and subsequently an in-depth analysis of the technical feasibility of artificial recharge, ie to determine whether or artificial recharge is not beneficial for the aquifer from the technical point of view, that is, considering only technical aspects such as the increase of resources that could be made available to applications or improving the quality of groundwater as a consequence of artificial recharge. The thesis is not considered economic aspects, which, given its enormous importance, will be a line of inquiry to follow in the future. The determination of the technical feasibility of artificial recharge has been done sequentially, structured into the following steps: a) the detailed study of the impact that has on artificial recharge the aquifer. This study was conducted after a campaign making data field in a year and a half, and has consisted mainly in the study of the evolution of the groundwater level influenced by the charge, and the parameters indicative of the quality of groundwater . B) an identification of potentially usable surplus water to increase in volume artificial recharge current level of the entire basin Girona. This determi 8 nation s 5ed and has performed at daily, considering all possible funding sources, which in this area are studied direct surface runoff and discharges from springs draining the aquifer known as the Sierra Noon. C) A mathematical model of flow in the aquifer. This model has revealed the residence time of water recharged in the aquifer, which is vital to raise its subsequent recovery. The mathematical model, once validated, have simulated different scenarios management artificial recharge. Once confirmed the technical feasibility of artificial recharge, it has proceeded with the design of a new facility recharge throughout the river basin Girona allowing significantly increase the volume of water artificially recharged in the aquifer.

Author: YANG CHANGBING.
Year: 2005.
University: A CORUÑA [www.udc.es].
Place of defense: E.T.S. de Ing. de C. C. y Puertos.
Place of preparation: E.T.S. de Ing. de C.C. y Puertos.

Summary: The compression of the quality of groundwater and the processes experienced by rocks in natural systems, studies of pollution in soil and groundwater and performance evaluation of waste storage facilities require a quantitative analysis of the migration of reactive substances in soil and groundwater. This requires the use of thermal models, hydrodynamic, biological and geochemical trailers (THBC), which takes into account both the subsurface flow, heat transfer, the transport of solutes in groundwater by advection, dispersion and diffusion and reactions chemical, as redox reactions, acid, aqueous complexation, biodegradation, surface complexation, and precipitation cation exchange / dissolution of minerals. In recent years have been developed sophisticated numerical models of transport of solutes multicomponent reactive. However, the existing models do not usually take into account simultaneously thermal processes, hydrodynamic, biological and geochemical. This thesis presents conceptual models and numerical THBC in fractured porous media and three-dimensional. The main contributions include: improvements in the series of numerical codes CORE, the stochastic modeling of the physical and geochemical heterogeneities of the porous media and applications of the models THBC. CORE is a general set of codes for modeling flow not isotérmo and transport of solutes coupled with a set of biogeochemical processes in porous media and fractured developed by the group at the University of A Coruna led by Dr. Javier Samper. During the course of this thesis were introduced significant changes in three of the codes in the series CORE: CORE2D V4, CORE3D V1 and INVERSE-BIOCORE2D. It has developed a solution semi-analítica for a general case of reactive transport with cation exchange multiple homogeneous porous media, which is valid for any arbitrary number of cations, using a transformation of equivalence and was compared with several numerical solutions for cases 1 - D. The Monte Carlo simulations were used to transport reactive with cation exchange domain vertical 2-D heterogeneous physical and geoquimicamente. It is assumed that the permeability as the cation exchange capacity are combining functions Gaussianas with semi-variogramas spherical. Factors delay implementation of the cations and the temporal and spatial moments are calculated to define the characteristics of the boom longitudinal reactive. The use of models coupled THBC illustrated in this thesis with several applications. The first seeks to interpret the behavior of sulfates and bicarbonates measured in the experiment Redox Zone in a fractured zone in Ãspà ¶ (Sweden) crossed by a tunnel. The microbiological processes are considered fermentation POC and anaerobic biodegradation of DOC. The second application is studying the use of molecular oxygen trapped in a potential almacenamento radioactive waste after its Swedish sealed. The model takes into account the microbiological breath of DOC and the oxidation of methane. The numerical results indicate that microbes play an important role in oxygen consumption. In the third application, the model THBC used for the evaluation of the role of microbiological processes in delaying the arrival of water rich in oxygen provien 8 and from 573 shielo glacial area in a fractured depth similar to that of a radioactive waste storage. Model results show that the front of oxidation is delayed by considering the influence of microorganisms. The latest application is filed simulation and interpretation of test dissemination spot DI-B done in full-scale and long-term in a sealed section of a vertical sounding drilled in the formation Opalinus Clay in the underground laboratory Mont Terri (Switzerland). It has used a model 3-D, which takes into account the anisotropy of dissemination to interpret the measured data and to derive the parameters of transport spot for the deuterium and iodine.

Author: ABARCA CAMEO ELENA.
Year: 2005.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: Aula 002, edifici C-1.
Place of preparation: EDIFICI D2 205 Campus NORD.

Summary: Modelling seawater intrusion (SWI) has evolved from a tool for understanding to a water management need. Yet, it remains a challenge. Difficulties arise from the assessment of dispersion coefficients and the complexity of natural systems that results in complicated aquifer geometries and heterogeneity in the hydraulic parameters. Addressing such difficulties is the objective of this thesis. Specifically, factors that may affect the flow and transport in coastal aquifers and produce heterogeneous salinity distributions are studied. First, a new paradigm for seawater intrusion is proposed since the current paradigm (the Henry problem) fails to properly reproduce observed SWI wedges. Mixing is represented by means of a velocity dependent dispersion tensor in the new proposed problem. Thereby, we denote it as "dispersive Henry problem". SWI is characterized in terms of the wedge penetration, width of the mixing zone and influx of seawater. We find that the width of the mixing zone depends basically on dispersion, with longitudinal and transverse dispersion controlling different parts of the mixing zone but displaying similar overall effects. The wedge penetration is mainly controlled by the horizontal permeability and by the geometric mean of the dispersivities. Transverse dispersivity and the geometric mean of the hydraulic conductivity are the leading parameters controlling the amount of salt that enters the aquifer. Second, the effect of heterogeneity was studied by incorporating heterogeneity in the hydraulic permeability into the modified Henry problem. Results show that heterogeneity causes the toe to recede while increases both the width and slope of the mixing zone. The shape of the interface and the saltwater flux depends on the distribution of the permeability in each realization. However, the toe penetration and the width of the mixing zone do not show large fluctuations. Both variables are satisfactorily reproduced, in cases of moderate heterogeneity, by homogeneous media with equivalent permeability and either local or effective dispersivities. Third, the effect of aquifer geometry in horizontally large confined aquifers was analyzed. Lateral slope turned out to be a critical factor. Lateral slopes in the seaside boundary of more than 3% cause the development of horizontal convection cells. The deepest zones act as preferential zones for seawater to enter the aquifer and preferential discharging zones are developed in the upwards lateral margins. A dimensionless number, Nby, has been defined to estimate the relative importance of this effect. All these factors can be determinant to explain the evolution of salinity in aquifers such as the Main aquifer of the Llobregat delta. Finally, a management model of this aquifer is developed to optimally design corrective measures to restore the water quality of the aquifer. The application of two different optimization methodologies, a linear and a non-linear optimization method, allowed (1) to quantify the hydraulic efficiency of two potential corrective measures: two recharge ponds and a seawater intrusion barrier; (2) to determine the water necessary to be injected in each of these measures to restore the water quality of the aquifer while minimizing changes in the pumping regime and (3) to assess the sustainable pumping regime (with and without the implementation of additional measures) once the water quality has been restored. Shadow prices obtained from linear programming become a valuable tool to qu 8 antify t 2e9 he hydraulic efficiency of potential corrective measures to restore water quality in the aquifer.

Author: MANETA LÓPEZ MARCO POLO.
Year: 2005.
University: EXTREMADURA [www.unex.es].
Place of defense: FACULTAD DE FILOSOFÍA Y LETRAS.
Place of preparation: FACUTLAD DE FILOSOFÍA Y LETRAS.

Summary: The thesis presents the development and application of a mathematical model to simulate the hydrological processes in small basins in ambient adehesados. Following a review of existing knowledge on the functioning of water in semi-arid and revising the simulation models currently available, the author develops a new model that describes the most important hydrological processes in time and space. The model, based on a solution implicit nonlinear wave kinematics for surface flow and channeling, and a model for two-dimensional flows in saturated porous media, is capable of simulating joint surface and surface fluxes and their interactions (return flows and base flows in the channel). It also includes a method for calculating the actual evapotranspiration from potential evaporation and the effects of interception by the woodland so it can be used on an ongoing basis (multievento in which there is recovery potential infiltration and soil retention retention of vegetation). The model can be classified as a hydrologic model spatially distributed dynamic and with a strong physical foundation. Once developed the model, the author applied to a basin pilot 100-hectare farm located in a low dehesa operating in the province of Caceres. The practical application proposes a method for generating the database needed to operate it model from experimental data points. Once generated the database, the most sensitive parameters are calibrated using a local search algorithm (algorithm Levenberg-Marquardt) in a context of optimization multiobjetivo.

Author: Zheng Liange.
Year: 2006.
University: A CORUÑA [www.udc.es].
Place of defense: E.T.S. de Ingenieros de Caminos, Canales y Puertos.
Place of preparation: Escuela Tecnica Superior de Ingenieros de Caminos, Canales y Puertos.

Summary: The concept of reference that handle most countries for the storage of radioactive waste in deep geological formations is based on a multi-system. The safety assessment of these stocks requires establish that the waste does not constitute a risk to humans and the environment over the next 100,000 years. This assessment requires mathematical models and numerical representing the thermal processes (T), hydrodynamic (H), mechanical (M) and geochemical (G), which will take place in the environment of storage. The main contributions of this thesis include: updating models THG prior to laboratory testing (CT-23 and cell permeability) and large-scale (model and in situ) project FEBEX (Full-scale Engineered Barrier EXperiment) the development of a number of models THMG for testing project FEBEX, development and improvement of codes THMG as FADES-CORE2D and INVERSE-FADES-CORE from existing codes to implement the testing project FEBEX, development a numeric code DCM-FADES-CORE dual permeability to flow multi not isotermo and reactive transport and the implementation of this code for a test of long-term patency. FADES-CORE2D is an updated version of FADES-CORE-LE which includes many upgrades and better as the implementation of subroutines for calculating the balance of mass and electric charge, consideration of kinetics in precipitation / dissolution of minerals, incorporation of a law creating permeability which depends on the ionic strength of the pore water, the implementation of the Pitzer equation to calculate the ratios of activity for large values of the ionic strength, consideration of the cross spread and the inclusion of the processes coupled chemical and thermal osmosis. This code is able to estimate a large number of parameters THMG with different types of measured data. The limitations of the models THG developed in FEBEX II for the cell CT-23 and mock trials and in situ has been bypassed by coupled models THMG. The model THMG for CT-23 reproduces the temperature, moisture content and porosity measures. We compared the results of chemical model THMG with data returned from the aqueous extracts and there has been an acceptable match for the chloride, sodium bicarbonate, potassium and calcium. Discrepancies between the concentrations of magnesium sulfate and returned as calculated with the model are due to uncertainties in the conceptual model geochemical. In the model THMG for the mock trial there has been a good match between the measured data and calculated values for the volume of injected water throughout the time scale, which suggests that a model THMG permeable variable and provides thermal osmosis a proper interpretation of hydration of the barrier bentonite. However, the relative humidity are lower than those calculated steps. A prediction long-term (200 years) indicates that the hydration of the barrier bentonite is a very slow process while retaining warming. In the model THMG trial spot there has been a good match between the measured data and calculated values for temperature, relative humidity and moisture content. The data returned from aqueous extract has been compared to the model results THMG, with a good match for most of the chemical species. The mechanical deformation affects the spatial distribution of species conservative and reactive because of their effect on the porosity. The surface complexation has a greater role that the mechanical deformation p 8 plows b a56 icarbonato and pH. Experimental evidence indicates that the bentonite has two types of porosity. The chemical imbalance between macro and micro domains requires use coupled models transportation reactive double continuous (Dual Continuous Models, DCM) to describe the flow of water, transport of solutes and geochemical reactions in bentonites. It has developed a code of finite elements, DCM-FADES-CORE, which allows direct and inverse modeling of multi-flow problems not isotermo and transport of solutes in reactive media monkey and bicontínuos. For models DCM has implemented a term water transfer of second order which takes into account the flow of water between the macro and micro domains produced by hydraulic pressure gradients and osmotic. For the term transfer solutes has implemented a term of order n obtained from the analytical approach to a solution for distribution in one dimension. The best results for the synthetic reference cases are obtained for a value of the exponent equal to 0.72. We have used two types of DCM for the interpretation of permeability testing of long duration, a model of continuous double with multiple knots and connected matrix (MDCCM) and another with a single node (DCCM). Both models provide much better results than those of single porosity model (SCM) and reproducing better data curves arrival of the chemical species. The excellent results obtained with the model DCCM in testing permeability confirm that the difficulties of parameterization of the model can be continuous double bypass by combining data from an experiment adequately monitored and the resolution of the inverse problem. The model DCCM is better than MDCCM for the interpretation of the test since the latter not only requires more CPU time but also requires calibrate more parameters.