HYDROGEOLOGY

Author: VITORIA CODINA LAURA.
Year: 2004.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE GEOLOGÍA.
Place of preparation: FACULTAD DE GEOLOGÍA , UNIVERSIADAD DE BARCELONA.

Summary: Groundwater is a freshwater resource of very good quality for human consumption, but very sensitive to pollution. In Catalonia, synthetic fertilizers and slurry are the cause of nitrate pollution of many aquifers. Nitrates experienced, in soil and water processes that can help reduce their concentration. Today we face a new challenge to the use of isotopic tools for identifying fuetes pollution. These tools can also be used to assess the evolution of the contaminant and predicting natural attenuation processes in order to apply, or not, other remedial measures. In this thesis referred to in the first place, the criteria for sampling groundwater methodologies for handling samples and analytical techniques utilized. Includes two methods, set up in the laboratory of the Group of Applied Mineralogía i Medi Ambient (MAIMA), preparation of water samples for analysis 015NNH4'015NN03Y or 180N03'Posteriormente presents a characterization of chemical and isotopic two types of sources of nitrate pollution in groundwater, synthetic fertilizers and manures. Finally, it presents four studies applied in the counties of Osona and Maresme (NE Spain), where the nitrogen isotopic compositions (015N and 0180) are used to characterize nitrate contamination of different origin, slurry and fertilizer, respectively. The isotopic compositions of water (or D, 0180), sulphates (034S, 0180), dissolved inorganic carbon (O13q and strontium (87Sr/86Sr), together with those of nitrates, are used to study the processes taking in soils yaguas and whether or not there is the natural attenuation of pollution. area Mareme is also studying the role of fertilizer in the salinization of the water and compares their chemical and isotopic composition with that comes the salinization is the result of the intrusion marina. different These studies have helped in this thesis: i) to characterize the chemistry and isotope synthetic fertilizers and slurry, drawing great interest for future studies of environmental contamination of soils yaguas ii) validating the using isotopic compositions, especially in the studies multi-isotópicos as tracers of sources of pollution and decay processes that affect them, and iii) to characterize and evaluate nitrate contamination of the areas studied in Osona and Maresme.

Author: NUÑEZ BENÍTEZ JULIÁN.
Year: 2004.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE GEOLOGÍA.
Place of preparation: FACULTAD DE GEOLOGÍA.

Summary: This work Doctoral Thesis, focuses his study on the characterization hidrogeoquímica and determination of arsenic contamination of groundwater and risks in the municipality of Zimapán (State of Hidalgo, Mexico). The research area is located in the northwestern part of the State of Hidalgo. The geologic framework of the region is dominated by carbonated rocks and terrígenas old Mesozoica and discordantly covered by a sequence vulcano-sedimentaria of Tertiary. The sequence of Mesozoic was folded in the late Cretaceous and early Tertiary, for the efforts compressive the Orogénia Laramide, creating large anticlinal structural and sinclinales. This was followed by a systematic sampling of groundwater from deep wells, open wells and springs. Moreover, in addition to river sediment sampling survey along the river Tolimán; We also sampled soil and vegetation (Schinus Molle L.) to determine the source of arsenic contamination in groundwater supplying the city of Zimapán. We analysis hidrogeoquímicos, geochemical and characterized the water, sediments, soil and vegetation in the study area by implementing various analytical methodologies that provide the concentration of major elements, minor and trace contaminants. The results of content elements majority and trace elements were compared with the existing national and international standards to be met quality control of drinking water. In samples of the major groundwater contaminants detected are sulphates, calcium, magnesium, arsenic, antimony, iron, manganese and zinc. The soil samples show high concentrations of contaminants are detected as: As, Ba, Cd, Cu, Pb and Zn; highlighting the elements for their toxicity: Ace and Pb. The vegetation was selected tree Pirul (Schinus Molle L.), which were collected leaves, ripe fruit and green. Samples better accumulate high concentrations of the elements are ripe fruit, then leaves, finally the fruit green. The contents of Au, Ag, As, Cd, Pb, Sb, Se, and Zn values ranging from low-medium-high. With the results of the samples of alluvial sediments are permitted to locate the main anomalies related to the natural variations of lithological types and geological processes of preconcentraciones of mineralization. The highest concentrations of the elements represented in the form of anomalies in the sediments are: As, Au, Ag, Ba, Cu, Cd, Cu, Sb, Pb, and Zn; by emphasizing its high toxicity anomalies: Ace and Pb. Finally it has been determined through surveys hidroguímicos and geochemical analysis of water, sediment, vegetation and soil pollution in this region Zimapán is due to: 1) For sources of natural formations Tamaulipas and soyatal, which Also included here is the participation of anthropogenic activity on the changes that have been generated in the study area.

Author: MARTINEZ LANDA M LOURDES.
Year: 2004.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: AULA CIHS (PLANTA BAIXA).
Place of preparation: EDIFICI D2 Campus NORD.

Summary: Low permeability fractured media (LFFM) can be viewed as consisting of a virtually impervious matrix transversed by more or less conductive fractures. Experience dictates that a few of these concentrate most of the flow, this controlling the overall behaviour of the medium. Therefore, they need to be characterized for proper understanding of the system. Unfortunately, no widely accepted methodology is available to this end. In this context the objective of this thesis is three fold: 1. Define a methodology to model this type of media. 2. Explain how the explicit modeling of hydraulically dominant fracture helps in explaining scale effects. 3. Apply the methodology to two real case studies: the FEBEX at Grimsel and the Ratones mine. The thesis consists of three independent but complementary papers. They are described below. First, I present a methodology to identify the most significant water conductive fractures. The method is based on the interpretation of cross-hole tests, and is supported by geology, geophysics and hydraulic data. This methodology has been applied to the hydrogeological characterization of a granitic block within FEBEX experiment, Switzerland. Characterising this medium starts by achieving a geometrical identification of the fractures, which demands mainly geological and geophysical data. Single borehole hydraulic tests help in neglecting those transmissive fractures, but the only means to assess the connectivity between points and the fractures extent consists of conducting cross-hole tests. The resulting geometry is later implemented into a 3D finite element mesh, where the fractures are simulated as 2D elements that are embedded into a 3D porous media that includes the effect of minor fractures. Hydraulic parameters have been obtained from the joint interpretation of cross-hole tests with 3D numerical models, using automatic calibration techniques and adjusting all the measurements simultaneously. This methodology has proved capable of reproducing steady state heads, and also of quantifying groundwater flow to the experimental area of the FEBEX tunnel. Different types of hydraulic tests (pulse, recovery, cross-hole and tunnel inflow measurements) have been performed in low permeability fractured granite around the FEBEX tunnel in Grimsel (Switzerland). We have interpreted the tests using conventional methods that treat the medium as a homogeneous one. Results display scale effects. Hydraulic conductivities increase, by orders of magnitude, with the volume of rock tested (from pulse to cross-hole tests). The objective of our work is to show that this scale effect is apparent. It reflects the limitations of the equivalent hydraulic conductivity derived from the homogeneous model interpretation of the tests. For this purpose, we have used the methodology described in the first paper. Transmissivity values used in the model to represent fractures are consistent with those derived from cross-hole tests, and the few single-hole tests at intervals intersecting fractures. On the other hand, matrix hydraulic conductivities are consistent with the remaining single-hole, short-time tests. This model can also be used to simulate observed heads and tunnel inflows. In summary, the final model is consistent with all the relevant measurements, taken at different support scales. This provides some insight into the issue of scale effects, which has been a topic of debate in the literature. In essence, the majority of small scale tests are performed in matrix intervals. Thus, any averaging of these values would suggest relatively small effective permeability. Yet large scale permeability of the rock is controlled by a few fractures, which provide high connectivity to the system, but are intersected by few testing in 8 tervals. 302 As a result, large scale permeability is qualitatively different and quantitatively larger than small scale permeability.

Author: ALCALA GARCIA FRANCISCO JAVIER.
Year: 2005.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: Edifici d2, Aula 001.
Place of preparation: EDIFICI D2 Campus NORD.

Summary: This dissertation provides the basis for calculating the rain to recharge aquifers by chloride ion balance (CMB), estimating contract stationary and discussing their value to distributed throughout Spanish. It brings a value of the fee charged in the rain expected to land in one place. The study of the variables of CMB is a major contribution to this work. The average rate of deposition of Cl in central peninsular is 0.2 to 0.5 g m-2 a-1. It is 1 to 30 g m-2 to-1 in the Atlantic coastal area and from 1 to 15 g m-2 to-1 in the Mediterranean and in both cases with a strong gradient between 0.1 and 1 g m-2 a-1 km-1. Similar aspect occurs in the island areas. The coefficient of variation in the rate of deposition of Cl increases 0,10-0,20 in coastal areas to more than 0.40 in the interior peninsula, but also increases with altitude topography. This pattern holds in the island territories. The use of the molar ratio R = Cl / Br and hydrochemical certain criteria for selecting samples have ensured that the Cl content in water recharge not affected its salinity is derived mainly from natural marine aerosol. This is between 10 and 50 mg / L in the Atlantic coastal area and about 25 to 100 mg / L in the Mediterranean. In the interior peninsular content is measured between 5 and 20 mg / L and less than 1 mg / L in areas summits. The tentative gradients are 0.2 to 1 mg L-1 km-1 in coastal areas. The situation is similar in both archipelagos, though contained in Cl and gradients greater. The coefficient of variation of the Cl content is 0,05-0,25 in coastal areas and 0.15 to 0.55 in the interior peninsula. In the archipelagos, the CV varies between 0.10 and 0.20 in coastal areas of all islands and between 0.10 and 0.40 in the smaller islands of relief. The flow of Cl by direct runoff, AE, ranging between 2 and 8 g m-2 to-1 in coastal areas, and between 0.02 to 0.05 g m-2 to-1 in zones interior. The CVAE varies between 0.10 and 0.30 in coastal areas, and between 0.40 and 1 in the interior. Gradients in the coast range between 0.05 and 0.20 g m-2 a-1 km-1, and are ~ 0.01 g m-2 a-1 km-1 in interior. The situation is similar in both archipelagos. The variables of CMB are characteristic of a place and have regionalized spatially through krigeado regular (KO) and inverse distance (ID), using a regular grid of 5113 cells of 10 km that covers the entire territory Spanish. Each node has interpolated a mean value and a value of coefficient of variation for each variable in that node to obtain a value of average annual recharge and value of its natural variability. Both methods provide a range of average annual recharge between 1 and 800 mm to-1 and estimated in a manner similar values between 100 and 300 mm to-1 and higher. Values below 100 mm to-1 are best estimated by the ID. The highest percentages of recharge are ~ 60% of the rain and occur in areas calcareous peninsular. The lower rates can be measured in detríticos land, in semi-arid island and peninsular and in certain areas where internal surface crystalline materials. The coefficient of variation of the recharge to the ID ranges between 0.15 and 1.7, and for the KO between 0.2 and 1.7. It is recommended to use a map of middle and recharge their coefficient of variation obtained by ID. The estimate of the recharge to the ground, whether or not the aquifer through CMB using geostatistical methods for spatial interpolation of data can be considered satisfactory in most parts of Spanish territory, is something inicerta in coastal areas, high variance with little or orographic available data, and is quite successful in areas with little control orográfico away from the coast and initial data available 8.

Author: Menció Domingo Anna.
Year: 2005.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: Facultad de Ciències..
Place of preparation: Institut de Ciència i Tecnologia Ambientals..

Author: Vázquez González Ana María.
Year: 2005.
University: A CORUÑA [www.udc.es].
Place of defense: E.T.S. de Ingenieros de Caminos, Canales y Puertos.
Place of preparation: E.T.S. de Ingenieros de Caminos, Canales y Puertos.

Summary: The industry of natural stone and, in particular, the granite is one of the pillars of the Galician economy. It can be expected that the increase in the production of granite developed leads inextricably coupled to the increase in production of wood dust (fine materials resulting from the processes of cutting and processing of granite ornamental). Therefore, to achieve a sustainable balance between the business sector and the preservation of the environment, according to the most stringent European standards, is a key objective at the moment. In connection with the analysis of the problem of wood dust may arise granite different approaches. This study seeks to answer three basic expectations that the sector granitero has raised. These issues have a particular interest also for the Administration: sorting and characterization of wood dust as a type of waste and how this affects their classification (inert or non-inert) More specifically: a) Influence on Ph water from the possible half receiver b) Identification of potential contaminant likely to present these materials, according to the content of metals and other pollutants from wood dust, their relative mobility and origne (rock itself or the various elements of the production cycle) The identification of properties inherent in the wood dust so that from them, possible otener them some economic advantage, or at least, better integration into the production cycle of the natural stone. The identification and study of applications feasible from the technical point of view and economic allowing an assessment of these residues tranformándolos in byproducts of the process of cutting stone. The thesis presents the results obtained from the characterization, focusing on aspects of nature and geochemistry in assessing their behavior hidronámico. Under volume of wood dust granite annually generated in the region of O Porriño, it is necessary to look for applications that require both large and small volumes of material transport distances. Thus, this research has focused on the application of the same barrier as waterproofing and / or sealed landfill.

Author: ALCOLEA RODRIGUEZ ANDRES.
Year: 2005.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: C-1, 002.
Place of preparation: EDIFICI D2 205 Campus NORD.

Summary: Geostatistical inversion represents a powerful tool to characterize heterogeneity. The pilot points method (PPM) is arguably the most flexible among the inverse approaches. However, the PPM suffers from instability. A tactic to combat instability consists of adding a regularization term to the objective function. Surprisingly, this option had not been applied to the PPM in a consistent manner. This dissertation aims at filling this gap. A modification of the PPM (termed âregularized pilot points method', RPPM) is presented. The main novelty consists of the addition of a plausibility term, which quantifies the departure of model parameters from their prior estimates. This term improves the identification of heterogeneity and the stability of the problem. This thesis consists of four self-contained papers. The RPPM is presented in the first paper and its performance is explored on a synthetic example. The method aims at obtaining the conditional estimation of transmissivity from direct measurements of this property and of dependent variables. Emphasis is placed on assessing the weighting of the plausibility term, which quantifies the importance of the prior information of parameters in the calibration. Results show that neglecting plausibility (standard option in the context of PPM) leads to the best fit of dependent variables, but to an unstable identification of model parameters. On the contrary, giving too much importance to plausibility biases the solution towards the prior information. The necessary optimal weighting of the plausibility term is done in the statistical framework of maximum likelihood estimation. This results in statistical consistency, increased stability and enhanced resolution. The added stability allows the use of as many pilot points as computationally feasible (what contradicts the traditional use of the PPM). These results are extended to the case of seeking stochastic simulations conditioned to direct measurements and dependent variables. Results show that optimal weighting of the plausibility term is also necessary. However, to search the optimum for each simulation (usually a large number) can be tedious. A key finding of this work is that, for most simulations, the optimum weight is the same as the one obtained by conditional estimation. This frees the modeller of the burden of having to seek the optimum weight for each simulation, but to obtain it just once using the RPPM in its variant of conditional estimation. The objective of the third paper is to test the ability of the RPPM for reproducing the small scale variability of hydraulic conductivity. Accepting that this variability cannot be identified, the effect of its presence in the identification of large scale connectivity patterns is analysed. In parallel, whether including small scale variability allows reproducing tailing in simulated breakthrough curves (BTCs). Results show that adding small scale variability leads to increased tailing. Furthermore, the main features of BTCs (arrival time, peak concentration and slope of the tail) are reproduced. At the same time, the main patterns of connectivity are represented. This suggests that, even though the small scale variability cannot be identified accurately, it must be accounted for in transport simulations. The motivation of the fourth paper is the characterization of the hydraulic connectivity patterns of a coastal aquifer in Spain. These patterns are best measured by hydraulic diffusivity D. Point values of D can be derived from the interpretation of tidal response. Unfortunately, available analytical solutions assume homogeneity. The objective of this work is to overcome this limitation and use tidal response to identify preferential flow paths. Spatial variability is characterized using the RPPM.

Author: CARREÑO CONDE FRANCISCO.
Year: 2005.
University: REY JUAN CARLOS [www.urjc.es].
Place of defense: ESCUELA SUPERIOR DE CIENCIAS EXPERIMENTALES Y TECNOLOGÍA.
Place of preparation: UNIVERSIDAD COMPLUTENSE.

Summary: The Prestige accident highlighted the need for tools and techniques to enable those responsible to plan and implement actions designed to prevent and mitigate the environmental, social and economic derived from marine pollution by oil. In this Doctoral Thesis has done an analysis of marine pollution from the Prestige techniques for Remote Sensing and Geographic Information Systems. The operation mounted by the authorities for the monitoring and control of marine pollution generated a large volume of information and data that has been integrated into a database mapping developed with GIS technology. This management tool geographic information, and atmospheric environment, identifying control elements in the behavior and derived from hydrocarbons. Furthermore, we have implemented remote sensing techniques to obtain properties of the ocean contextualizan and allow the correct interpretation of the SAR radar satellite imagery. These images appear many oceanographic and meteorological phenomena that radiometric and morphologic features similar to marine pollution. To discriminate against this pollution of these other elements, have been contrasted with data from sightings stain conducted in the operating of the Prestige, and it was found necessary to rely on information from the media that is integrated into the database mapping. Although the effectiveness of the technique is not 100%, if it is interesting to raise its use to supplement other observational techniques in surveillance systems and control of marine pollution.

Author: ROBLES ARENAS VIRGINIA MARIA.
Year: 2006.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: AULA C1-CIMNE.
Place of preparation: EDIFICI D2 205 Campus NORD.

Summary: The Sierra de Cartagena-La Union (SCU) is characterized by having formed one of the largest accumulations of Pb-Zn of the Iberian Peninsula. At present this is abandoned mining area, with plans for restoration and hydrogeological general nonexistent characterizing a potential source of contaminants in an area with scarce water resources as the SE Spanish. This thesis has been carried out by the definition of operating model hydrogeological of WCS, has been characterized water, mining waste, salt efflorescence and sediment. It has been necessary to conduct a thorough field work, laboratory and cabinet. The aquifer fractured the WCS is very heterogeneous. It consists of metamorphic materials and Detritic (shale, quartzite, phyllites, and material carbonated), highly fractured by the tectonic activity and mining. Its thickness varies between 400-800 m. Data piezométricos and hydrochemical show an aquifer divided into blocs hydrogeological delimited faults N-130. The flow direction is nearly parallel to this system of fracturing; due to preferential flow along faults and mining galleries, (the location of the mineralization exploited by underground mining is associated with faults N-130). The surface piezométrica comes in the form of low dome alignment that describes the short mining indicative of the main area of replenishment. This trend piezométrica noted in piezometrías conducted with historical data, which showed that no significant changes in levels piezométricas at least in the last thirty years, which also indicates a balance between inflows and outflows to the aquifer. The water from the aquifer WCS shows a wide range of variation of the physical and chemical parameters because of the great heterogeneity of the medium. The upwelling not sour and acidic are generated by a rapid flow of water infiltrated into the aquifer, the water can interact or not the mineralization and remains miners, in the case of upwelling acidic water circulates in a preferential through galleries mining enriched sulphate, metals and acquiring a pH acid. Samples from the mining short respond to a mixture of water runoff, rain and groundwater. Samples from wells miners have a greater period of residence. Facies predominant anion is sulphated and its concentration varies between 55-40300 mg / L, the electrical conductivity varies from 1000-21700 9S/cm, pH 1.9-7.8, and the maximum concentration of metals is reached: Zn 4090 mg / L , Faith 1260 mg / L Mn 436 mg / L. The sulfate ion comes from the oxidation of the mineralization, the dissolution of salt efflorescence, and the mobilization of ocher and suspended material from accumulations of waste. The results obtained confirm that the sulfate is better indicator that the pH and the concentration of metals disorders induced antrópicamente in mining areas of metal sulphides.

Author: JODAR BERMUDEZ JORGE.
Year: 2006.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: Aula D2-212.
Place of preparation: EDIFICI D2 205 Campus NORD.

Summary: In the post-operational phase of a Low/Intermediate-Low radioactive waste repository, gas will be generated in the caverns due to anaerobic corrosion of metals, and also chemical and microbial degradation of organic substances. Previous investigations on gas migration have indicated that discrete water-conducting features (e.g. shear zones) are mainly responsible for gas transport from the caverns through the geosphere. Two phase flow processes occur in these water conducting features; the continuity and spatial distribution of pore spaces, the pore size distribution and the interfacial forces of the three phases gas-water-rock have a significant influence on gas transport. The main difficulties to be resolved when simulating two-phase flow processes in fractured rock are: · The description of the internal heterogeneity of the individual water conducting features. The influence of channelling along preferential flow paths is even more important than for single phase fluid flow, because gas transport takes place more or less exclusively along the most transmissive channels. · The determination of effective mass exchange coefficients of the relevant components of the system. Mass exchange may occur between three phases (gas-water-rock). It depends on the spatial distribution of water and gas along the water conducting features (i.e. specific surface of contact areas between phases), and on the solubility and diffusivity of the different components, but also on a couple of state variables of liquid phase (initial content of dissolve/free gas, initial pressure). The work presented in this thesis aims to improve the understanding of the physics of single and multiphase transport phenomena, to be able to develop a quantitative description of gas transport in shear zones to overcome in a satisfactory way the problems described above.