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In the current context of population growth and climate change, it is essential to effectively manage groundwater resources, to improve their quality, and to determine the behaviour of certain contaminants. Groundwater quality can be worsened most often by anthropogenic factors but can also be altered by natural factors depending on the chemical signatures of water sources (i.e., hydrochemical reactions) as a result of mixing processes. In these cases, the use of mixing calculations and multivariate statistical analysis (MSA) methods is crucial for determining the reactions that occur, the origin and fate of the detected compounds, ions or parameters, and the behaviour of the system. Thus, these methods ascertain processes that affect the chemical composition (i.e., quality) of groundwater bodies, and this information is needed for designing groundwater management strategies that exploit aquifers in a sustainable way. However, these methods are rarely employed, as few investigations that consider them focus on urban aquifers. Here, mixing calculations and other MSA methods that consider major ions and environmental isotopes are utilized in an aquifer located in a rural area associated with the Niebla-Posadas aquifer, Spain, where groundwater quality has deteriorated due to geogenic factors. This study proves the usefulness of these methods for deriving essential information that is needed (1) to properly manage the exploitation of aquifers, (2) to avoid the deterioration of groundwater bodies, and (3) to identify the reasons behind poor groundwater quality., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was supported by the “Agencia Estatal de Investigación” from the Spanish Ministry of Science and Innovation and the IDAEA-CSIC, a Centre of Excellence Severo Ochoa (CEX2018-000794-S). EP gratefully acknowledges the support received through the grant RYC2020-029225-I funded by MCIN/AEI/ 10.13039/501100011033 and by “ESF Investing in your future” and the Award for Scientific Research into Urban Challenges in the City of Barcelona 2020 (20S08708) from the Barcelona city council. RC gratefully acknowledges the financial support from the Balearic Island Government through the Margalida Comas postdoctoral fellowship programme (PD/036/2020). The authors would like to thank the European Commission, the Spanish Foundation for Science and Technology (FECYT) and Spanish State Research Agency (AEI) for funding in the frame of the collaborative international consortium (URBANWAT) financed under the 2018 Joint call of the WaterWorks2017 ERA-NET Cofund. This ERA-NET is an integral part of the activities developed by the Water JPI. Additionally, the authors would also like to thank the Ministry of Science, Innovation and Universities, for funding the project UNBIASED (Ref: RTI2018-097346-B-I00) under the 2018 call of the “Proyectos de I+D Retos Investigación.

Correction to: Scientific Reports https://doi.org/10.1038/s41598-023-29701-x, published online 14 February 2023 The Supplementary Information published with this Article contained an error. In “Appendix C”, Figures C1 and C2, the label of the Y-axis “Concentration (ng/L)” was incorrectly given as “Concentration mg/l”.

Low-enthalpy geothermal energy (LEGE) is a carbon-free and renewable source to provide cooling and heating to infrastructures (e.g. buildings) by exchanging their temperature with that of the ground. The exchange of temperature modifies the groundwater temperature around LEGE installations, which may contribute to enhancing the capacity of aquifers to degrade organic contaminants of emerging concern (OCECs), whose presence is significantly increasing in urban aquifers. Here, we investigate the impact of LEGE on OCECs and their bioremediation potential through numerical modelling of synthetic and real-based cases. Simulation results demonstrate that: (i) LEGE facilities have the potential to noticeably modify the concentrations of OCECs; and (ii) the final impact depends on the design of the facility. This study suggests that optimized LEGE facility designs could contribute to the degradation of OCECs present in urban aquifers, thus improving groundwater quality and increasing its availability in urban areas., This investigation has received funding from the Barcelona city council (Award for Scientific Research into Urban Challenges in the City of Barcelona 2020-20S08708). In addition, it has been supported by the grants CEX2018-000794-S funded by MCIN/AEI/10.13039/501100011033, PID2021-128995OA-I00 funded by MCIN/AEI/10.13039/501100011033 and FEDER “one way to make Europe”, and RYC2020-029225-I funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”. This research has also been carried out within the framework of the activities of the Spanish Government through the “Maria de Maeztu Centre of Excellence” accreditation to IMEDEA (CSIC-UIB) (CEX2021-001198). MT acknowledges the Beatriu de Pinós fellowship, funded by the Agency for Management of University and Research Grants (AGAUR; reference code: 2020BP00280). EP, LS and RCM thank the Ibero-American Programme of Science and technology for development (CYTED- Programa de ciencia y tecnologia para el desarrollo) under project 719RT0585. RCM acknowledges the support received through the Margalida Comas postdoctoral fellowship programme (PD/036/2020) funded by the Balearic Island Government. Finally, VV acknowledges support from the Spanish Ministry of Science and Innovation through the project HydroPore (PID2019-106887GB-C32). EV would like to thank the European Commission, the Spanish Foundation for Science and Technology (FECYT) and Spanish State Research Agency (AEI) for funding in the frame of the collaborative international consortium (URBANWAT) financed under the 2018 Joint call of the WaterWorks2017 ERA-NET Cofund, with ref PCI2019-103616. This ERA-NET is an integral part of the activities developed by the Water JPI. Additionally, EV would also like to thank the Ministry of Science, Innovation and Universities, for funding the project UNBIASED (Ref: RTI2018-097346-B-I00) under the 2018 call of the “Proyectos de I+D Retos Investigación”.

We enclose the database used to demonstrate the advantages of use the AkvaGIS tools. AkvaGIS is a novel, free and open source module included in the FREEWAT plugin (http://www.freewat.eu/) for QGIS that supplies a standardized and easy-to-use workflow for the storage, management, visualization and analysis of hydrochemical and hydrogeological data. Hydrochemical data was collected in in the Walloon region (Belgium) in spring 2016 within the framework of a project that investigated the occurrence and indirect emissions of greenhouse gases (GHGs) from groundwater at the regional scale (Jurado et al., 2018). Data from major and minor ions are used in this work to display the functionalities of AkvaGIS.

Se muestra la revisión de la información existente sobre la composición isotópica del oxígeno (δ18O) y del hidrógeno (δ2H) de la molécula del agua en el sector Norte de los Andes chilenos, entre 17°30´y 25°30´ de latitud sur. Durante el verano austral, los vientos del este favorecen la entrada de humedad atlántica, predominantemente a través de la cuenca del Amazonas, que originan más del 80% de la precipitación anual que se produce en los Andes Centrales. La cordillera de los Andes Centrales actúa como una barrera geográfica respecto a la humedad del Atlántico, siendo uno de los factores que produce en la costa norte chilena el área climática más seca de la Tierra. Se revisan brevemente los antecedentes sobre la hidrología isotópica, los que han permitido dar respuesta a cuestiones tales como el origen de las precipitaciones que recargan los acuíferos, la localización de las zonas de recarga, las posibles conexiones entre cuencas, y la identificación de los procesos que modifican la isotopía de las aguas, como la evaporación o los efectos geotérmicos. Se ha observado en las aguas superficiales, subterráneas y precipitaciones del norte de Chile, que existe un enriquecimiento en isótopos pesados en sentido norte sur, desde la región de Arica y Parinacota a la región de Antofagasta. La investigación de la isotopía de las precipitaciones y de las aguas superficiales y subterráneas es necesaria para un manejo sustentable de los recursos hídricos y para comprender el actual clima y las variaciones climáticas pasadas y futuras.

Urban aquifers are a strategic resource for the development of cities, which are expected to amass 70% of the world population by 2050. However, a vast array of organic pollutants, like contaminants of emerging concern (CECs), are continuously introduced in aquifers by different recharge sources. CECs, which have been increasingly reported in groundwater, pose ecological risks even at trace levels, including interference with the endocrine system of organisms, microbiological resistance and accumulation in ecosystems. Furthermore, their effects on human health, soil, plants and animals are largely unknown. In this context, CECs must be removed from groundwater to safely use it to cover the growing demand of tap water and as a strategic resource at specific times (e.g., droughts). The degradation rate of organic contaminants depends, among others, on the redox conditions and the water temperature, and both vary noticeably in urban aquifers as a result of anthropogenic activities, like Aquifer Thermal Energy Storage (ATES). Therefore, to understand the behaviour of common CECs under different physico-chemical conditions is of paramount importance to predict their behaviour in urban contexts and design remediation strategies. Thus, we are developing a set of laboratory experiments under different physico-chemical conditions (i.e., temperature and redox) that can be found in urban aquifers to determine the behaviour of different CECs . A suite of representative CECs (reported in the city of Barcelona, Spain) representing a broad range of physicochemical properties and (a)biotic reactivity has been chosen to conduct experiments. Our results will have significant implications for predicting the behaviour of organic contaminants in urban aquifers while improving existing remediation strategies.

In western Mediterranean areas, seawater intrusion (SWI) used to be a major issue during the 1970’s decade due to the agricultural exploitation of the fertile lands located near to the coast. Proper pumping management nearly solved the problem, but the later economic development carried out by industries and tourism added an extra pressure to these sensitive systems, reactivating SWI in some cases. A good example of this situation can be found in the northeastern coast of Spain. In this area, the topographic configuration is controlled by medium reliefs and sloped piedmonts that discharge precipitation through ephemeral streams towards the sea. These torrential flows have a groundwater component that generates a coeval submarine groundwater discharge (SGD) with the intrusion of seawater. SGD strongly determines the health of marine environments, reason why is classically neglected in SWI research: in this area, SGD has been characterized measuring natural radioactive tracers (223Ra, 224Ra, 226Ra, 228Ra) in open sea campaigns, but the impact of mixing of this seaward flow and SWI within the aquifer remains unknown. The presence of different lithologies also determines the kind of geochemical reactions that modify the conservative behavior of the tracers used to measure SGD, as well as the localization of preferential flowpaths, making hard to quantify and predict both types of reciprocal flows (SGD and SWI). To be able to understand these interactions, a detailed characterization of the solid and liquid phase of the aquifer at different scales has been performed. To do so, we built a dedicated experimental site in a coastal alluvial aquifer in the Maresme coast line (Barcelona, Spain): the Argentona experimental site. Different types of geophysical logging (induction, spectral gamma ray and magnetic susceptibility) were deployed in the drilled wells to characterize the salinity gradient and distinguish sedimentary bodies. Also, the lithology and the geochemistry of discrete samples recovered from the drilling stage, were determined at smaller scale using X-ray diffraction, rock total analysis for chemical composition, cation exchange capacity, surface area, 226Ra and 228Ra content and grain size distribution. Moreover, groundwater composition was characterized performing mayor and minor elements analysis and radium and radon isotopes quantifications. This characterization of the geological heterogeneity will serve as a basis for future interpretation of field tests and modelling studies focused on the Argentona experimental site.

Due to the general increase of water scarcity (Steduto et al., 2012), water quantity and quality must be well known to ensure a proper access to water resources in compliance with local and regional directives. This circumstance can be supported by tools which facilitate process of data management and its analysis. Such analyses have to provide research/professionals, policy makers and users with the ability to improve the management of the water resources with standard regulatory guidelines. Compliance with the established standard regulatory guidelines (with a special focus on requirement deriving from the GWD) should have an effective monitoring, evaluation, and interpretation of a large number of physical and chemical parameters. These amounts of datasets have to be assessed and interpreted: (i) integrating data from different sources and gathered with different data access techniques and formats; (ii) managing data with varying temporal and spatial extent; (iii) integrating groundwater quality information with other relevant information such as further hydrogeological data (Velasco et al., 2014) and pre-processing these data generally for the realization of groundwater models., {"references":["Rossetto R., Borsi I., Schifani C., Bonari E., Mogorovich P., Primicerio M. (2013). SID&GRID: Integrating hydrological modeling in GIS environment. Rendiconti Online Societa Geologica Italiana, Vol. 24, 282-283 Steduto, P., Faurès, J.M., Hoogeveen, J., Winpenny, J.T., Burke, J.J. (2012). Coping with water scarcity: an action framework for agriculture and food security. ISSN 1020-1203 ; 38 Velasco, V., Tubau, I., Vázquez-Suñé, E., Gogu, R., Gaitanaru, D., Alcaraz, M., Sanchez-Vila, X. (2014). GIS-based hydrogeochemical analysis tools (QUIMET). Computers & Geosciences, 70, 164-180"]}

Sol·licitant de l’informe: Barcelona Cicle de l'Aigua, S.A.

El tunel del AVE que atraviesa Barcelona fue construido con una tuneladora tipo EPB. El trazado del túnel pasa bajo la Sagrada Familia (declarada patrimonio de la humanidad por la UNESCO), y debido a los riesgos que entrañaba la construcción, un comité designado por la UNESCO actuó como observador externo durante la excavación del túnel. Las dos principales preocupaciones era los movimientos del suelo producidos por la construcción y los impactos causados por la obra sobre el acuífero. Ambas se tuvieron en cuenta durante la fase de diseño del túnel para evitar eventos inesperados durante la construcción

Cuando se estudian las aguas subterráneas en zonas urbanas deben tenerse en cuenta una serie de cuestiones específicas. La urbanización del territorio afecta significativamente al ciclo del agua tanto en cantidad como en calidad, en particular a la parte relacionada con la recarga y descarga de los acuíferos. Además las aguas pueden afectar a las infraestructuras urbanas subterráneas como sótanos, parkings, túneles de Metro o ferrocarril, conducciones, etc. Por estos motivos el estudio de las aguas subterráneas en zonas urbanas emerge con fuerza dentro de la hidrogeología. Algunos de los temas específicos para su estudio son: 1) Variaciones del nivel freático causadas por cambios en los usos del suelo y del agua; 2) Contaminación de las aguas subterráneas por la presencia de focos contaminantes tanto puntuales como difusos; 3) Caracterización y cuantificación de los componentes del balance hidrogeológico; 4) especificidades en la modelación del flujo subterráneo y el transporte de contaminantes; y 5) Integración de los datos hidrogeológicos para su gestión. Algunos de estos temas se ilustran aquí sobre el ejemplo de la ciudad de Barcelona. En los últimos años, tanto desde el ámbito público como privado, se ha llevado a cabo un amplio estudio hidrogeológico de la ciudad. El ascenso del nivel freático se ha convertido en un serio problema para muchas estructuras subterráneas, principalmente parkings y la red del Metro. Este ascenso se ha debido básicamente a la disminución en la explotación de las aguas subterráneas por una reducción significativa del consumo de agua para usos industriales. Aquí se presenta una evaluación de los principales términos que afectan a la recarga cuyo resultado es la cuantificación del balance hidrogeológico en el periodo comprendido entre 1965 a 1995. Se ha cuantificado en unos 40 hm3/a la cantidad total de agua que debe bombearse de los acuíferos para mantener los niveles freáticos a las cotas actuales. Si se bombean cantidades menores los niveles freáticos seguirán ascendiendo y continuaran los problemas. Se han sugerido algunos usos alternativos para estas aguas.Este caso puede considerarse un buen ejemplo de como la evolución de la urbanización en cualquier ciudad genera una serie de problemas respecto la disponibilidad y calidad de las aguas subterráneas con las implicaciones tanto sociales como económicas que esto comporta. Para un buen conocimiento de la hidrogeología urbana es preciso un análisis cuantitativo del flujo de agua y de su calidad, para ello es preciso 1) identificar los procesos hidrogeológicos; 2) caracterización de acuíferos y modelación y 3) gestión de los recursos hídricos. Al aplicar esta metodología a Barcelona se ha obtenido, entre otras cosas, un modelo capaz de ser utilizado como herramienta de gestión. Estos modelos se podrán aplicar si las aguas subterráneas quedan contempladas como un elemento más a tener en cuenta por los gestores locales. Un tema clave para el estudio de la hidrogeología urbana es la evaluación de los diversos términos que componen la recarga (agua de la red de abastecimiento, del alcantarillado, agua de escorrentía urbana, infiltración directa, etc.) Discriminar todos estos términos es importante para evaluar el balance, para conocer el riesgo de contaminación de los acuíferos y para plantear una correcta gestión. Es necesario conocer cuales son los diversos compuestos hidroquímicos e isotópicos presentes en las aguas de recarga. El objetivo es identificar, y si es posible cuantificar, las diversas fuentes de recarga y sus proporciones. Se ha revisado un buen número de experiencias y casos internacionales que listan en el uso de diversos tipos de trazadores aplicados a los estudios de aguas subterráneas.La cuantificación de las diversas fuentes de recarga se puede establecer a partir de balances de solutos. El puntos críticos son: 1) la gran cantidad de fuentes de recarga existentes que implican tener que usar un gran número de especies conservativas; 2) la incertidumbre en las concentraciones de estas fuentes y 3) los errores de medida.Teniendo en cuenta estas limitaciones se presenta un método basado en el análisis estadístico multivariado para el cálculo de las proporciones de mezcla de las fuentes de recarga en un gran número de puntos de mezcla. Este método está basado en la presunción que las medidas de las concentraciones contienen errores. Minimizando la función de verosimilitud respecto a las concentraciones de las fuentes y de las mezclas se llega a un problema de optimización. Para resolver este problema se presenta un algoritmo de aplicado a dos ejemplos sintéticos. Los resultados confirman la conjeturas de partida, es decir, las concentraciones de las mezclas contienen información sobre las concentraciones de las fuentes. Así pues, al haber consistencia entre ambos implica que una mejora en los cálculos de las mezclas y también en el conocimiento más preciso de las fuentes. Esta metodología se ha aplicado a los acuíferos de Barcelona. El primer paso ha sido la identificación de las fuentes de recarga potenciales: agua de abastecimiento, con dos tipologías diferentes, aguas residuales y de escorrentía urbana, aguas de infiltración directa ,aguas de infiltración del río Besós y aguas de intrusión marina. Después de su estudio hidroquímico e isotópico se han determinado ocho especies químicas más o menos conservativas para identificar las posibles fuentes de recarga. La aplicación de este método estadístico ha permitido calcular las proporciones de mezcla de las diversas fuentes de recarga en las diversas zonas de los acuíferos de la ciudad., A number of specific issues must be considered when dealing with groundwater in urban areas. Urbanization significantly affects the natural water cycle, both in terms of quantity and quality. In particular, the main contributors to recharge and discharge clearly differ from those in natural systems. Moreover, water can affect underground city infrastructures, such as basements, public transport services (trains, subway, .), and conductions. As a result, urban groundwater is emerging as a distinct branch of hydrogeology. Topics that are specific to urban groundwater include: 1) Fluctuations in groundwater levels caused by changes in land and water uses; 2) Pollution problems caused by point or non-point sources in urban areas; 3) Characterization and quantification of the components contributing to groundwater balance; 4) Specific characteristics of groundwater flow and solute transport models in urban areas; and 5) Integration of data for sustainable urban water management. Some of these issues are illustrated here for the case of Barcelona, where both the public and the private sectors have carried out a comprehensive hydrogeological study during the last years. Rising of groundwater levels beneath the city of Barcelona has become a serious problem to urban structures, such as the subway and underground parking areas. This rise is mainly due to a decline in groundwater exploitation, following a reduction in high water-consuming industrial activity in the city. We present an evaluation of the main terms affecting recharge in the city. The outcome is a global groundwater balance for the period 1965-1995. It has been quantified that a total rate of 40 million m3 per year should be pumped from the aquifers underneath the city in order to keep to the present groundwater levels. A lesser amount would lead to a rise in levels, and to continuing problems. Possible uses for this additional water are suggested.This case can be considered an example of how urbanisation poses some threats to both availability and quality of groundwater resources in large cities worldwide, with their corresponding significant social, environmental and economic implications. A good knowledge of urban hydrology requires a detailed quantitative analysis of not only water fluxes, but also their quality. In any real case study one has to face at least three aspects: (1) process identification, (2) aquifer characterisation and modelling, and (3) water resources management. This three-fold methodology has been applied to the city of Barcelona. The outcome is a groundwater model which may, among other things, become a management tool. This is an important step towards considering groundwater as one of the topics to be taken into account in city planning. One of the key issues in urban hydrogeology is the evaluation of the relative contribution of the different sources of recharge (water from mains and sewers, direct infiltration, runoff, etc.). Discriminating among recharge sources is important for the overall recharge evaluation, for assessing groundwater pollution risks and for groundwater management. To do so, it is necessary to know the different hydrochemical compounds and isotopes present in groundwater and recharge water. The objective is to identify, and if possible to quantify, the various recharge water types and their proportion. We have reviewed a large number of cases and international experiences illustrating the use of several tracers in urban groundwater studies. Quantification of the contribution from the different recharge terms can be achieved by means of solute mass balances. The critical points in the process are: (1) the large amount of source terms, which leads to the necessity of a large number of conservative species to be used, (2) the uncertainty in the concentrations of sources, and (3) the measurement errors. A method based on multivariate statistical analysis is presented for estimating the proportions in which a small number of end-member waters are mixed in a large number of samples. The method is based on assuming that errors affect all concentration measurements. Maximizing the likelihood of these with respect to both mixing ratios and end-member concentrations leads to a general constrained optimization problem. An algorithm for solving this problem is presented and applied to two synthetic problems. Results confirm the conjecture that motivates this work. That is, mixtures concentration measurements contain information about end-member concentrations. As a result, ensuring that the latter are consistent with the former leads to a significant improvement of not only end-member estimates, but also mixing ratio estimates.This method has been applied to the city of Barcelona. In this city a number of potential sources were identified. These include: losses from the water supply network (with two different sources of water), losses from sewers, infiltration from the Besòs River, infiltration in unpaved areas, and seawater intrusion. After studying the results from the chemical and isotopical analyses, eight chemical species were found to be conservative and to provide a potential for source discrimination. The application of the statistical analyses allowed us to compute the proportions of each recharge source for a number of different locations in Barcelona.

The development of an underground station below the water table requires rigorous and careful planning. As such an in depth knowledge of the station construction designs and the related hydraulic behavior are required in order to design the most appropriated drainage system. Moreover, it is important to ensure the correct drainage of the excavation site to avoid liquefaction and to minimize water seepage. As an example of underground construction we consider the tunnel for the new line in the Barcelona metropolitan area (Línia 9) through the town of Prat de Llobregat in the Llobregat River’s delta, which is currently under development. Most of the tunnel sections are constructed with Tunnel Boring Machines (TBM) and the stations and the ventilation shafts are constructed using “Cut & Cover” technology between sheet pile walls. A typical station on the L9 line lies partially between the shallow and the main aquifer. Specifically, it is located in the middle layer which in made up of silts and clays. In order to design the most appropriated drainage system we present a methodology whereby we generalize the hydraulic problem. This method enables rapid and efficient estimation of fluxes as well as a general understanding of the problem in a simplified manner.

Basic univariate statistics and key geostatistical parameters of estimates of hydraulic conductivity obtained at the decimeter scale by two different methods are presented and compared. The two estimates are based on (1) the empirical Kozeny-Carman formulation, and (2) impeller flowmeter tests. The former provides values of conductivity, KGS, based on particle size distributions. Impeller flowmeter techniques allow inferring conductivities, KFM, from measurements of vertical flows within a borehole. Data obtained during an extensive monitoring campaign at an experimental site located near the city of Tübingen, Germany, are considered. Statistics of the natural logarithm of KGS and KFM at the site are similar in terms of mean values (with averages of ln KGS being slightly smaller than those of ln KFM) and differ in terms of variogram ranges and sample variances. The correlation between the two sets of estimates is virtually absent. Additional data from two different sites already presented in the literature allow comparing conductivity estimates from flowmeter and grain-size distributions (or permeameter measurements) taken at adjacent wells and support the finding that KGS and KFM lack correlation. The analysis highlights the difficulty in obtaining meaningful quantitatively comparable hydraulic conductivity data at the decimetric scale.

This work is motivated by a sound understanding of the chemical processes that affect the organic pollutants in an urban aquifer. We propose an approach to quantify such processes using mixing calculations. The methodology consists of the following steps: (1) identification of the recharge sources (end-members) and selection of the species (conservative and non-conservative) to be used, (2) identification of the chemical processes and (3) evaluation of mixing ratios including the chemical processes. This methodology has been applied in the Besos River Delta (NE Barcelona, Spain), where the River Besos is the main aquifer recharge source. A total number of 51 groundwater samples were collected from July 2007 to May 2010 during four field campaigns. Three river end-members were necessary to explain the temporal variability of the River Besos: one river end-member is from the wet periods (W1) and two are from dry periods (D1 and D2). This methodology has proved to be useful not only to compute the mixing ratios but also to quantify processes such as calcite and magnesite dissolution, aerobic respiration and denitrification undergone at each observation point.

Hace unos años se decidió descontaminar el embalse de Flix, afectado por vertidos de residuos por un empresa química durante todo el siglo pasado. Los residuos formaron 4 lóbulos de sedimentos en el río, con elevadas concentraciones de Mercurio, compuestos orgánicos volátiles (COV´s), residuos de producción de acetileno (Ca(OH)2) y pesticidas organoclorados. Se ha realizado un modelo 0D de transporte reactivo de la concentración en el agua conforme se excavan los sedimentos transitorio y explícito en excel, calibrado hasta Septiembre 2014 con datos semanales de la empresa extractora FCC. El modelo concluía dos graves problemas al terminar la excavación: Elevada concentración de Hg y pH (12.4), equilibrado con portlandita Desde Marzo de 2015 se observó un acusado descenso de pH y Hg. Nuestro objetivo ha sido encontrar la causa de estos descensos, para ello se han realizado simulaciones, muestreos y experimentos de laboratorio.

Texto en español con resumen y palabras claves en español e inglés, Los salares son una fuente importante de minerales y especialmente de litio. Además, lagunas y humedales de alto valor ecológico están asociados frecuentemente a la zona de la interfaz salina (zona de mezcla) resultante del contraste de densidades entre el agua dulce recargada en el frente montañoso y la salmuera evaporada desde el salar que se ha instalado en la depresión. Esta zona se caracteriza por la presencia de flujos verticales, que condicionan la hidrodinámica a escala de cuenca. Es necesario establecer una metodología que permita incorporar el efecto de la interfaz salina en los modelos de agua subterránea que están enfocados a la gestión de sus recursos minerales y valores ecológicos. Dicha metodología consta de 3 fases: 1) recogida de datos físico-químicos en campo, 2) cartografía 3D de la zona de mezcla y 3) modelación numérica. Se presenta una cartografía tridimensional (3D) de la zona de mezcla del Salar de Atacama. Las diferentes geometrías de la zona de mezcla se han interpretado utilizando un modelo numérico de flujo y transporte de solutos. El resultado del modelo muestra una pendiente de la zona de mezcla similar a la obtenida a través de los datos de campo, la cual es más laxa que en los modelos previos, que consideraron un medio poroso homogéneo. Cuanto mayor es la permeabilidad del acuífero superior, menores son los niveles hidráulicos y, por lo tanto, menor es la pendiente de la interfaz salina. La presencia de unos pocos metros de materiales altamente permeables (abanicos aluviales o evaporitas karstificadas) en las unidades estratigráficas superiores de los salares es suficiente para modificar la geometría regional de la zona de mezcla. Se propone utilizar esta cartografía 3D como base para corregir los niveles piezométricos de agua dulce y de agua mezcla a niveles equivalentes de salmuera, con el fin de reducir el coste computacional de futuros modelos numéricos tridimensionales enfocados a la gestión de las aguas subterráneas de los salares = Salt flats are an important source of minerals and especially of lithium. In addition, lakes and wetlands of high ecological value are frequently associated with the saline interface zone (mixing zone) resulting from the density contrast between the freshwater coming from the rainfal infiltration on the mountains and the brine produced mainly by evaporation in the depressions. This zone is characterized by vertical flows that condition the hydrodynamics at a basin scale. It is necessary to establish a methodology that allows the incorporation of the effect of the saline interface into groundwater models for the management of the mineral resources and ecological values. This methodology consists of 3 steps: 1) physical-chemical data collection in the field, 2) 3D mapping of the mixing zone and 3) numerical modelling. A three-dimensional (3D) mapping of the mixing zone of the Salar de Atacama is presented. The mixing zone geometry was interpreted using a numerical flow and solute transport model. The results from the model show a slope of the mixing zone that is similar to that obtained with the field data, which is more relaxed than in the previous models that considered a homogeneous porous medium. The higher the permeability of the upper aquifer is, the lower the slope and the shallower the mixing zone become. The presence of a few metres of highly permeable materials (alluvial fans or karstified evaporites) in the upper stratigraphic units of the salt flats is enough to condition the regional geometry of the saline interface. The use of this 3D mapping is proposed as a basis for the correction of the freshwater and mixing water heads to brine heads to reduce the computational cost of 3D numerical models for groundwater management in salt flats., Instituto de Diagnóstico Ambiental y Estudios del Agua, Consejo Superior de Investigaciones Científicas, España, Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya, España, Centre for Microbiology and Environmental Systems Science, Environmental Geosciences,University of Vienna, Austria, Real Academia de Ciencias Exactas, Físicas y Naturales de España, España, Unidad de Zaragoza, Instituto Geológico y Minero de España, España

The aim of this paper is to demonstrate how the integration of differential interferometric synthetic aperture radar (D-InSAR) and levelling improves the monitoring of ground deformation phenomena, thereby enabling their complete understanding. The complementarity between D-InSAR and levelling is illustrated through a case study of the construction of a road tunnel beneath Glòries Square, Barcelona; D-InSAR is employed to continuously monitor the works, notably the dewatering of the site. This study focuses primarily on D-InSAR data obtained from the processing of Sentinel-1A data following a persistent scatterer interferometry procedure. The spatial distribution of the deformation and its temporal evolution are analysed with detailed hydrogeological and piezometric data. The magnitude of deformation is discussed using levelling data and an analytical estimation based on the hydromechanical parameters of the ground obtained from a pre-existing hydrogeological numerical model and pumping tests. The D-InSAR results are shown to be essential for identifying the origin of ground deformation and the constraints on its spread. Such observations at the construction site and district (~2 km radius) scales with sub-centimetric deformation are precious contributions of D-InSAR data, whereas levelling offers a more accurate quantification of the deformation, although this remains an open issue to be further investigated., The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Barcelona d'Infraestructures Municipals S.A. (BIMSA, Ajuntament de Barcelona), as promoter of the construction works in Glòries Square, funded the works of IDAEA-CSIC and CTTC in technical assistance for the Construction Management office. TYPSA (Técnica Y Proyectos S.A.) and Tec-4 (Tec-Cuatro S.A.), as responsible companies for the Construction Management, provided information and data from the works (geometries, operations, monitoring data, etc.). The authors would like to specifically thank the collaboration of Àngel López Arilla (BIMSA), Josep Torrentallé (BIMSA), Laura Baró López (TYPSA), Marc Esquius Berengueras (ESTEYCO S.A.) and Raúl Sánchez Rodríguez (Euro Geotecnica S.A.). This work has been also partially funded by the Spanish Ministry of Economy and Competitiveness through the DEMOS project “Deformation monitoring using Sentinel-1 data” (Ref: CGL2017-83704-P); by the European Commission, the Spanish Foundation for Science & Technology (FECYT) and State Research Agency (AEI) in the frame of the collaborative international consortium URBANWAT (PCI2019-103616) financed under the Water JPI Joint Call 2018 of the WaterWorks 2017 ERA-NET Cofund; and by the Spanish Ministry of Science, Innovation and Universities through (1) the project UNBIASED (Ref: RTI 2018-097346-B-I00) under the 2018 call of the “Proyectos de I + D Retos Investigación“; and (2) Project CEX2018-000794-S, IDAEA-CSIC, Centre of Excellence Severo Ochoa. The authors would also like to thank the assistance of Dr. Nieves Lantada Zarzosa (Universitat Politècnica de Catalunya, UPC) and Dr. Estanislao Pujades Garnes (Helmholtz Centre for Environmental Research - UFZ).

To reduce uncertainty in the identification of the recharge areas in the Peripheral Aquifer of the Salar de Atacama (SdA), a few studies have investigated the isotopic characteristics and moisture sources of precipitation in the SdA basin. In the present study, the seasonal cycle of meteorological parameters and the relationships of this cycle with sea surface temperature anomalies are shown, the sources of humidity are identified, and the types of clouds producing precipitation are defined. Finally, the isotopic compositions of precipitation, surface water and groundwater in the SdA basin and the Altiplano-Puna Plateau basins are analysed to identify the area recharging the northern, eastern and southern subbasins of the SdA. In summer, when the highest temperature, relative humidity and precipitation values of the year are recorded, the precipitation is due to deep convection. The trajectories of the arriving air masses can be classified into three groups: from the North Atlantic Ocean across the Amazon basin, from the South Atlantic Ocean across the La Plata River basin and the Gran Chaco, and from the Pacific Ocean. In winter, when the temperature, relative humidity and precipitation are lower, the moisture masses come from the Pacific Ocean. Winter precipitation is more depleted in heavy isotopes than summer precipitation. The isotopic analysis of precipitation, surface water and groundwater shows that recharge of the eastern subbasins of the SdA occurs by diffuse infiltration of precipitation and concentrated infiltration of surface water, both within the hydrographic basin of the SdA. The meteoric source of the waters in the Altiplano-Puna Plateau basins is isotopically lighter than the waters found in the side basins of the SdA, so there is no significant water quantity transfer to the peripheral aquifers of the SdA from outside the hydrographic basin., The authors thank SQM (Chile) for their support and cooperation, Atacama Large Millimeter/submillimeter Array (ALMA), to the staff of the Paso Jama border crossing and indigenous communities of Atacameñas de Caspana and Toconce responsible for the Geysers of El Tatio, for their support in the obtaining the isotope data. Thanks to Xavier Querol and Cristina Carnerero for their help and with model HYSPLIT, and to Dr. Rotman Criollo for his help. Sonia Valdivielso and Enric Vázquez-Suñé would like to thanks Spanish Ministry of Science and Innovation (Project CEX2018-000794-S) IDAEA-CSIC, Centre of Excellence Severo Ochoa. The authors are thankful to Dr. Carlos Ayora for his critical and constructive comments on the manuscript of this paper.

Pharmaceuticals, such as non-steroidal anti-inflammatory drugs (NSAIDs) and their metabolites, have become a major concern due to their increasing consumption and their widespread occurrence in the environment. In this paper, we investigate the occurrence of NSAIDs and their metabolites in an urban aquifer, which may serve as a potential resource for drinking water, and propose a methodology to assess the removal of these substances in the river–groundwater interface. Then, risk quotients (RQs) are computed, in order to determine the risk posed by the single NSAIDs and their mixture to human health. To this end, six NSAIDs and two metabolites were collected from an urban aquifer located in the metropolitan area of Barcelona (NE, Spain), in which the major pollution source is a contaminated river. All of the target NSAIDs were detected in groundwater samples, where the concentrations in the aquifer were higher than those found in the river water (except for ibuprofen). Diclofenac, ketoprofen, propyphenazone and salicylic acid were detected at high mean concentrations (ranging from 91.8 ng/L to 225.2 ng/L) in the aquifer. In contrast, phenazone and mefenamic acid were found at low mean concentrations (i.e., lower than 25 ng/L) in the aquifer. According to the proposed approach, the mixing of river water recharge into the aquifer seemed to some extent to promote the removal of the NSAIDs under the sub-oxic to denitrifying conditions found in the groundwater. The NSAIDs that presented higher mean removal values were 4OH diclofenac (0.8), ibuprofen (0.78), salicylic acid (0.35) and diclofenac (0.28), which are likely to be naturally attenuated under the aforementioned redox conditions. Concerning human health risk assessment, the NSAIDs detected in groundwater and their mixture do not pose any risk for all age intervals considered, as the associated RQs were all less than 0.05. Nevertheless, this value must be taken with caution, as many pharmaceuticals might occur simultaneously in the groundwater., IDAEA-CSIC is a Centre of Excellence Severo Ochoa (Spanish Ministry of Science and Innovation, Project CEX2018-000794-S). A. J gratefully acknowledges the support from the Secretary for Universities and Research of the Ministry of Economy and Knowledge of the Government of Catalonia and the Marie Sklodowska-Curie COFUND of the programme H2020 (BP3, contract number 801370). The authors would like to thank the European Commission, the Spanish Foundation for Science & Technology (FECYT) and State Research Agency (AEI)) for funding in the frame of the collaborative international consortium (URBANWAT) financed under the 2018 Joint call of the WaterWorks2017 ERA-NET Cofund. This ERA-NET is an integral part of the activities developed by the Water JPI. Additionally, authors would also thank the Ministry of Science, Innovation and Universities, for funding the projects UNBIASED (Ref: RTI2018-097346-B-I00) under the 2018 call of the “Proyectos de I+D Retos Investigación” and INTEGRATE (Ref: PID2019-107945RJ-I00) under the 2019 call of the “Proyectos de I+D Retos Investigación”.

The drawdown in the nucleus led to a reduction of 94% of the evaporation flow that characterized the natural regime, resulting in an impact of 0.15 m3·s−1 in the water balance. The evaporation rate in the mixing zone, in both periods, reached values of 5.84 mm·d−1 in the lakes and values

River floodplains sustain irrigated agriculture worldwide. Despite generalised groundwater level falls, limited hard data are available to apportion groundwater sources in many irrigated regions. In this paper, we propose a workflow based on: hydrochemical analysis, water stable isotopes, radiocarbon contents and multivariate statistical analysis to facilitate the quantification of groundwater source attribution at regional scales. Irrigation water supply wells and groundwater monitoring wells sampled in the alluvial aquifer of the Condamine River (Queensland, Australia) are used to test this approach that can easily be implemented in catchments worldwide. The methodology identified four groundwater sources: 1) river/flood water; 2) modified river/flood water; 3) groundwater recharged through regional volcanic materials and 4) groundwater recharged predominantly through sands and/or sandstone materials. The first two sources are characterised by fresh water, dominant sodium bicarbonate chemistry, short residence time and depleted water stable isotope signatures. Groundwater sources 3 and 4 are characterised by saline groundwater, sodium chloride chemistries, enriched water stable isotopes and very low radiocarbon contents, inferred to correspond to long residence times. The majority of wells assessed are dominated by flood water recharge, linked to decadal >300 mm rainfall events and associated flooding in the region. The approach presented here provides a groundwater source fingerprint, reinforcing the importance of floodwater recharge in the regional water budgets. This apportioning of groundwater sources will allow irrigators, modelers and managers to assess the long-term sustainability of groundwater use in alluvial catchments., This research was funded by the Cotton Research and Development Corporation, Australia, Grant Number UNSW1401. The authors would like to thank Lucienne Martel for her assistance with sample collection. We would also like to thank all cotton growers who provided access to their irrigation water supply wells and the staff at the Queensland Department of Natural Resources and Mines (Toowoomba, Office) who facilitated at short notice access to the government groundwater monitoring wells. Dr. Matthias Raiber (CSIRO) is also acknowledged for conversations and assistance in the field during sampling. Chris Dimovski, Barbora Gallagher, Robert Chisari, Henri Wong, Brett Rowling and Vlad Levchenko from ANSTO are also acknowledged for their constant logistic and analytical support. Laura Scheiber and Enric Vázquez-Suñé would like to thanks Spanish Ministry of Science and Innovation (Project CEX2018-000794-S). The authors also thank Lisa Williams for editing and proofreading the manuscript.

Each scientist is specialized in his or her field of research and in the tools that he or she uses during the research in a specified site. Thus, he or she is the most suitable person for improving the tools by overcoming their limitations to realize faster and higher quality analysis. However, most scientists are not software developers. Hence, it is necessary to provide them with an easy approach that enables non-software developers to improve and customize their tools. This paper presents an approach for easily improving and customizing any hydrogeological software. It is the result of experiences with updating several interdisciplinary case studies. The main insights of this approach have been demonstrated using four examples: MIX (FORTRAN-based), BrineMIX (C++-based), EasyQuim and EasyBal (both spreadsheet-based). The improved software has been proven to be a better tool for enhanced analysis by substantially reducing the computation time and the tedious processing of the input and output data files., R. Criollo thanks Barcelona Cicle de l’Aigua (BCASA) and the Catalan Industrial Doctorates Plan of the Secretariat for Universities and Research, Ministry of Economy and Knowledge of the Generalitat de Catalunya for their financial support. The staff of the Department of Geotechnical Engineering and Geosciences of the Universitat Politècnica de Catalunya (UPC) and the Institute of Environmental Assessment and Water Research (IDAEA-CSIC) are gratefully acknowledged for their useful comments and suggestions. We also thank Scott Tacker and Dadiyorto Wendy for their contributions which improved the manuscript

Antibiotics, such as sulfonamides (SAs), have recently raised concern as wastewater treatment plants (WWTPs) partly remove them, and thus, SAs continuously enter the aquifers. In this context, the aims of this work are to (1) investigate the temporal evolution of SAs and metabolites in an urban aquifer recharged by a polluted river; (2) identify the potential geochemical processes that might affect SAs in the river-groundwater interface and (3) evaluate the ecological and human health risk assessment of SAs. To this end, 14 SAs and 4 metabolites were analyzed in river and urban groundwater from the metropolitan area of Barcelona (NE, Spain) in three different sampling campaigns. These substances had a distinct behavior when river water, which is the main recharge source, infiltrates the aquifer. Mixing of the river water recharge into the aquifer drives several redox reactions such as aerobic respiration and denitrification. This reducing character of the aquifer seemed to favor the natural attenuation of some SAs as sulfamethoxazole, sulfapyridine, and sulfamethizole. However, most of the SAs detected were not likely to undergo degradation and adsorption because their concentrations were constant along groundwater flow path. In fact, the intensity of SAs adsorption is low as the retardation factors are close to 1 at average groundwater pH of 7.2 for most SAs. Finally, risk quotients (RQs) are used to evaluate the ecological and human health risks posed by single and mixture of SAs in river water and groundwater, respectively. Life-stage RQs of the SAs detected in groundwater for the 8 age intervals were low, indicating that SAs and their mixture do not pose any risk to human beings. Concerning the environmental risk assessment, SAs do not pose any risk for algae, fish and crustaceans as the RQs evaluated are further lower than 0.1., A.J acknowledges the support from the Secretary for Universities and Research of the Ministry of Economy and Knowledge of the Government of Catalonia and the Marie Sklodowska-Curie COFUND of the programme H2020 (BP3, contract number 801370). M.S.D.C acknowledges the Generalitat de Catalunya (Water and Soil Quality Unit, 2017-SGR-1404) and the Spanish Ministry of Science and Innovation (Project CEX 2018-000794-S). E.V.S would like to thank the European Commission, the Spanish Foundation for Science & Technology (FECYT) and State Research Agency (AEI)) for funding in the frame of the collaborative international consortium (URBANWAT) financed under the 2018 Joint call of the WaterWorks2017 ERA-NET Cofund. This ERA-NET is an integral part of the activities developed by the Water JPI. Additionally E.V.S also thank the Ministry of Science, Innovation and Universities, for funding the project UNBIASED (Ref: RTI 2018-097346-B-I00) under the 2018 call of the “Proyectos de I + D Retos Investigación.

The Salar de Atacama (SdA) is the largest Li reserve globally. The origin of Li, together with the rest of solutes, has been object of debate. Thus, rock weathering at low temperature, hydrothermal leaching or magmatic origin together with subsequent evaporation has been hypothesized. However, the extreme Li enrichment (>4000 mg/L) and the location of the Li-Mg-rich brines around the Salar Fault System (SFS) that crosses the nucleus of the SdA in half remain unexplained. The objective of this work is to define the thermohaline groundwater flow in the SdA basin to account for the genesis of its extreme Li enrichment. Thermohaline flow modelling has demonstrated the critical effect of the minimum hydraulic head (MHH) of the regional water table on the groundwater flow of salt flats. The MHH divides the basin into two isolated hydrodynamic systems and constitutes the endpoint towards which the most evaporated brines converge. The spatial mismatch between the locations of the Li-Mg-rich brines in the central-western zone of the nucleus (in the SFS) and the MHH in the easternmost zone of the nucleus discards recent evaporative concentration of the recharge water as the main mechanism of Li enrichment. Moreover, the persistence of a saline interface surrounding the nucleus at depth, regardless of the temperature gradient, also precludes lateral recharge (predominantly from the east) to ascend along the SFS. On the other hand, the computed thermohaline flow is compatible with the remobilization of buried layers of Li-Mg-enriched salts and/or clays by dilute recharge waters coming from the west or southwest of the basin. Here, the role of faults and density-driven flow is key to allow efficient downward and upward flow rates that favour the remobilization of Li and Mg., The authors acknowledge Fabien Magri for sharing the BrineDensity plug-in and FEFLOW for sponsoring the license. The authors thank Craig Simmons and James Wards for sharing their experience during the modelling work and Juan Hidalgo for his fruitful contribution to the discussion. Finally, David Dempsey and an anonymous reviewer are greatly acknowledged for their comments and corrections which significantly improved the original version.

The steady increase of geothermal systems using groundwater is compromising the renewability of the geothermal resources in shallow urban aquifers. To ensure sustainability, scientifically-based criteria are required to prevent potential thermal interferences between geothermal systems. In this work, a management indicator (balanced sustainability index, BSI) applicable to groundwater heat pump systems is defined to assign a quantitative value of sustainability to each system, based on their intrinsic potential to produce thermal interference. The BSI indicator relies on the net heat balance transferred to the terrain throughout the year and the maximum seasonal thermal load associated. To define this indicator, 75 heating-cooling scenarios based in 23 real systems were established to cover all possible different operational conditions. The scenarios were simulated in a standard numerical model, adopted as a reference framework, and thermal impacts were evaluated. Two polynomial regression models were used for the interpolation of thermal impacts, thus allowing the direct calculation of the sustainability indicator developed as a function of heating-cooling ratios and maximum seasonal thermal loads. The BSI indicator could provide authorities and technicians with scientifically-based criteria to establish geothermal monitoring programs, which are critical to maintain the implementation rates and renewability of these systems in the cities. © 2018 Elsevier Ltd, This work was performed by the Geological Survey of Spain (IGME) under the Cooperation Agreement framework between IGME and the Ebro Hydrographic Confederation (CHE) for the specific arrangement entitled “The application of a groundwater flow and heat transport numerical model for the simulation of management strategies of geothermal installations in the city of Zaragoza”. Alejandro García-Gil gratefully acknowledges MIKE by DHI for the sponsored FEFLOW license.

The aim of this study is to investigate the occurrence of faecal indicator and microbial pathogens (bacteria and virus) in the shallow urban aquifer of the Besòs River Delta (NE Spain). To this end, human adenovirus (HAdV) and Norovirus of genogroups I and II (NoV GI and NoV GII) as well as the faecal indicator bacteria (FIB) Escherichia coli (EC) and faecal enterococci (FE) were monitored in groundwater and in the River Besòs in December 2013 and in July 2104. None of the targeted pathogens were detected in groundwater in December 2013 but contamination of human origin was observed in approximately 50% of the points sampled in July 2014 reaching concentrations up to 99 GC/100 mL for HAdV. Generally, microbial concentrations in river water were higher than those detected in groundwater. This observation indicates that pathogens are naturally attenuated when river water infiltrates and flows through the aquifer, however HAdV were detected at a sampling point located at 380 m from the river in the absence of FIB. The presence of human viral contamination may represent a risk for the use of groundwater as a drinking water source. Further research is needed to understand the dynamics of pathogens in river–groundwater interface over long time periods and a wide range of flow conditions (wet and dry periods) since the urban groundwater of this aquifer might be a valuable drinking water resource in Barcelona especially during drought periods. The methodology followed in this research can be applied to other urban aquifers with similar purposes since the scarcity and contamination of freshwater resources are worldwide issues. © 2019 Elsevier B.V., A. J gratefully acknowledges the financial support from the Excellence Initiative of the German Federal and State Governments through the “Open Topic Postdoc Position Fellow” at the Technische Universität Dresden. The authors would like to thank the European Commission, the Spanish Foundation for Science and Technology (FECYT) and Spanish State Research Agency (AEI) for funding in the frame of the collaborative international consortium (URBANWAT) financed under the 2018 Joint call of the WaterWorks2017 ERA-NET Cofund. This ERA-NET is an integral part of the activities developed by the Water JPI. Additionally authors would also thank the Ministry of Science, Innovation and Universities, for funding the project UNBIASED (Ref: RTI2018-097346-B-I00) under the 2018 call of the “Proyectos de I+D Retos Investigación.

The Salar de Atacama is one of the most well-known saline endorheic basins in the world. It accumulates the world main lithium reserves and contains very sensitive ecosystems. The objective of this work is to characterize the hydrodynamics of the Salar de Atacama, and to quantify its complex water balance prior to the intense brine extraction. The methodology and results can be extrapolated to the groundwater flow and recharge of other salt flats. A three-dimensional groundwater flow model using low computational effort was calibrated against hundreds of hydraulic head measurements. The water infiltrated from the mountains ascends as a vertical flux through the saline interface (mixing zone) produced by the density contrast between the recharged freshwater and the evaporated brine of the salt flat nucleus. This water discharges and is largely evaporated from lakes or directly from the shallow water table. On the other hand, the very low hydraulic gradients, coupled with the presence of the mixing zone that operates as barrier, leads the salt flat nucleus to act as a hydrodynamically quasi-isolated area. The computed water table shows the lowest hydraulic head in the salt flat nucleus near the discharge at the mixing zone. The groundwater balance of the Salar de Atacama in its natural regime was quantified resulting in an inflow/outflow of 14.9 m3·s−1. This balance considers the basin as an endorheic system. The very low infiltration values that are generally assumed for hyperarid basins are not consistent with the hydrogeology of the Salar de Atacama. Indeed, very high infiltration rates (up to 85% of rainfall) occur because of the high degree of fracturing of rocks and the scarce vegetation. This high infiltration is consistent with the light isotopic composition of the water from the recharge area (Altiplano). Therefore, the existence of additional inflows outside the basin is unlikely. © 2018, The authors acknowledge Sociedad Química y Minera de Chile S.A. (SQM) for their support and sharing data throughout the hydrogeological characterization of the SdA site. M.A. Marazuela gratefully acknowledges the financial support from the AGAUR (Agència de Gestió d'Ajuts Universitaris I de Recerca, Generalitat de Catalunya) and the European Union (grant number 2017FI B1 00194). Finally, we thank three anonymous reviewers for their valuable comments.

The Salar de Atacama is used as a case study to analyse and quantify coupled natural (evaporation and recharge) and anthropogenic processes (pumping of lithium-rich brine) to abstract their patterns to other salt flats using a three-dimensional groundwater flow model. Important changes in the dynamics of the water table between the pre-operational period (1986–1994) and operational period (1994–2015) are observed. The water table exhibited a gradual drawdown during the pre-operational period because the evaporation was greater than the recharge for most of these periods. This negative balance was counteracted by some sharp rises that were produced by direct rainfall events on the salt flat. The deep lateral recharge that arrived from the mountains did not produce abrupt changes in the water table because the rainfall events in the mountains were damped by the distance of the recharge zone and great thickness of the unsaturated zone. The natural evolution of the water table was modified by the intensive brine pumping that was performed in the south-western Salar de Atacama during the operational period. As evaporation depends on the water table depth, the pumping caused a drawdown of the water table, resulting in an evaporation rate reduction that partially compensated for the pumped brine in the water balance of the basin. This effect is defined as the damping capacity of salt flats. Thus, salt flats have a high capacity for dampening oscillations in their water table in response to both natural and anthropogenic disturbances which is of great importance for the management of lake and wetland ecosystems and brine exploitation. The limit of the dampening capacity of salt flats is defined by the evaporation extinction depth, which is in the range of 0.5–2 m. © 2018 Elsevier B.V., The authors acknowledge Sociedad Química y Minera de Chile S.A. for their support and sharing data throughout the hydrogeological characterization of the SdA site. M.A. Marazuela gratefully acknowledges the financial support from the AGAUR (Agència de Gestió d’Ajuts Universitaris i de Recerca, Generalitat de Catalunya) and the European Union (grant number 2018FI B2 00068). Finally, we thank four anonymous reviewers for their valuable comments.

The skin effect is an important issue associated with a loss of hydraulic efficiency in pumping systems. In this paper, a comprehensive study is conducted to determine how the evolution of the skin effect over time affects the productivity and functionality of brine exploitation systems in a crystalline halite aquifer. Several double-packer system tests have been interpreted via groundwater modeling to hydrogeologically characterize the investigated aquifer. A numerical groundwater flow model that accounts for the heterogeneity of the multilayer halite aquifer and the transient well skin effect on the brine exploitation system is presented to explain the continuous drawdown during three months of constant-rate brine extractions. Numerical results obtained suggested that an exponential decay function of permeability over time was required in a wellbore skin zone to reproduce numerically experimental observations during brine exploitation. The empirical exponential function obtained specifically for this case study was generalized, and coefficients considered were discussed to infer their physical and geochemical dimensions related to the mixing process triggering heterogenous reactions responsible for the hydraulic loses. Our results will be useful for predicting the spatial and temporal losses of hydraulic efficiency and for evaluating the lifetimes of brine exploitation infrastructure. © 2019 Elsevier B.V., Personnel of the Sociedad Química y Minera de Chile (SQM) generously provided access to data, accommodations and logistical support in the field. The authors would like to extend gratitude to the associate editor and two anonymous reviewers for their valuable and constructive comments that led us to an improvement of the work.

The quantification of the hydraulic parameters is important to support decision making in environmental impact assessment, water resources evaluation or groundwater contamination remediation, among others. These kind of parameters derived from aquifer tests usually encompasses a vast amount of data (spatial and non-spatial) for management and analysis. To achieve this in a clear and understandable manner, the GIS environment is a useful instrument. Development of innovative software to analyze pumping tests in a GIS platform environment to support the hydraulic parameterization of groundwater flow and transport models is presented in this paper. This new platform provides three interconnected modules to improve (a) pumping test interpretation code through a user-friendly interface, (b) pumping test data visualization supported by a set of tools that perform spatiotemporal queries in a GIS environment and (c) the storage and management of hydrogeological information. Additionally, within the GIS platform, it is possible to process the hydraulic parameters obtained from the pumping test and to create spatial distribution maps, perform geostatistical analysis and export the information to an external software platform. Finally, a real-world application in the area of Barcelona (Spain) has shown the usefulness of the tools developed in support of hydrogeological analysis., This work was supported by the Catalan Industrial Doctorates Plan of the Secretariat for Universities and Research, Ministry of Economy and Knowledge of the Generalitat de Catalunya. The authors would like to thank J. Hidalgo, A. Medina and A. Nardi for their support during the work’s development. R. Criollo gratefully acknowledges the financial support from the Grup d’Hidrologia Subterrània, SGR: 2014 SGR 1377.

The conceptualisation of a groundwater system involves continuous monitoring and evaluation of a large number of parameters (e.g., hydraulic parameters). Regarding hydraulic properties of the aquifers, their quantification is one of the most common problems in groundwater resources and it is recognised that all methods to obtain them have their limitations and are scale dependants. Therefore, it is necessary to have methods and tools to estimate them within a spatial context and to validate their uncertainty when they are applied in an upper scale. All these datasets collected and generated to perform a groundwater conceptual model are often stored in different scales and formats (e.g., maps, spreadsheets or databases). This continuous growing volume of data entails further improving on how it is compiled, stored and integrated for their analysis. This thesis contributes to: (i) provide dynamic and scalable methodologies for migrating and integrating multiple data infrastructures (data warehouses, spatial data infrastructures, ICT tools); (ii) to gain higher performance of their analysis within their spatial context; (iii) to provide specific tools to analyse hydrogeological processes and to obtain hydraulic parameters that have a key role in groundwater studies; and (iv) to share open-source and user-friendly software that allows standardisation, management, analysis, interpretation and sharing of hydrogeological data with a numerical model within a unique geographical platform (GIS platform). A dynamic and scalable methodology has been designed to harmonise and standardise multiple datasets and third-party databases from different origins, or to connect them with ICT tools. This methodology can be widely applied in any kind of data migration and integration (DMI) process, to develop Data warehouses, Spatial Data Infrastructures or to implement ICT tools on existing data infrastructures for further analyses, improving data governance. A higher performance to obtain hydraulic parameters of the aquifer has been addressed from the development of a GIS-based tool. The interpretation of pumping tests within its spatial context can reduce the uncertainty of its analysis with an accurate knowledge of the aquifer geometry and boundaries. This software designed to collect, manage, visualise and analyse pumping tests in a GIS environment supports the hydraulic parameterization of groundwater flow and transport models. To enhance the hydraulic parameters quantification, a compilation, revision and analysis of the hydraulic conductivity based on grain size methodologies have been performed. Afterwards, the uncertainty of applying these methods on a larger scale has been addressed and discussed by comparison of the upscaling results with pumping tests. Finally, a sharing, open-source and user-friendly GIS-based tool is presented. This new generation of GIS-based tool aims at simplifying the characterisation of groundwater bodies for the purpose of building rigorous and data-based environmental conceptual models. It allows to standardise, manage, analyse and interpret hydrogeological and hydrochemical data. Due to its free and open-source architecture, it can be updated and extended depending on the tailored applications. La conceptualització d’un sistema hidrogeològic implica una continua monitorització i avaluació d’una gran quantitat de paràmetres (e.g., paràmetres hidràulics). Pel que fa als paràmetres hidràulics de l’aqüífer, la seva quantificació és un dels problemes més comuns als estudis hidrogeològics. És àmpliament reconegut que els mètodes per obtenir aquest tipus de paràmetres tenen les seves limitacions i són dependents de l’escala d’anàlisi. Per aquest motiu, cal disposar de mètodes i eines per estimar-los dins del seu context espacial i validar la seva incertesa quan s’apliquen en una escala superior d’anàlisi. Les dades recopilades i generades per realitzar un model conceptual hidrogeològic sovint s'emmagatzemen en diferents escales i formats (e.g., mapes, fulls de càlcul o bases de dades). Aquest volum de dades en continu creixement requereix d'eines i metodologies que millorin la seva compilació i gestió per al seu posterior anàlisi. Les contribucions realitzades en aquesta tesi son: (i) proporcionar metodologies dinàmiques i escalables per migrar i integrar múltiples infraestructures de dades (infraestructures de dades espacials i no espacials, o la implementació d'eines TIC); (ii) obtenir un major rendiment de l'anàlisi hidrogeològic tenint en compte el seu context espacial; (iii) proporcionar eines específiques per analitzar processos hidrogeològics i obtenir paràmetres hidràulics que tenen un paper clau en els estudis d'aigües subterrànies; i (iv) difondre software de codi lliure i de fàcil accés que permeti l'estandardització, gestió, anàlisi, interpretació i intercanvi de dades hidrogeològiques amb un model numèric dins d'una única plataforma de informació geogràfica (SIG). S'ha dissenyat una metodologia dinàmica i escalable per harmonitzar i estandarditzar múltiples conjunts de dades de diferents orígens, o bé per connectar aquestes infraestructures de dades amb eines TIC. Aquesta metodologia pot ser implementada en qualsevol tipus de procés de migració i integració de dades (DMI), per a desenvolupar infraestructures de dades espacials i no espacials, o bé per implementar eines TIC a les infraestructures de dades existents per a anàlisi addicionals; millorant així la governança de les dades. Un major rendiment per obtenir els paràmetres hidràulics de l'aqüífer s'adreça des del desenvolupament d'una eina SIG. La interpretació dels assaigs de bombament dins del seu context espacial, pot reduir la incertesa del seu anàlisi amb un coneixement precís de la geometria i els límits de l'aqüífer. Aquest software dissenyat per recopilar, administrar, visualitzar i analitzar els assaigs de bombament en un entorn GIS, dóna suport a la parametrització hidràulica dels models de flux i transport d'aigües subterrànies. Per millorar la quantificació dels paràmetres hidràulics, es va realitzar una compilació, revisió i anàlisi de la conductivitat hidràulica basada en metodologies de mida de gra. Posteriorment, s'ha considerat i discutit la incertesa d'aplicar aquests mètodes en una escala major comparant els resultats de la millora d'escala amb les proves de bombament. Finalment, es presenta una eina SIG lliure, de codi obert i de fàcil aplicació. Aquesta nova generació d'eines SIG pretenen simplificar la caracterització de les masses d'aigua subterrània amb el propòsit de construir models conceptuals ambientals rigorosos. A més, aquesta eina permet estandarditzar, gestionar, analitzar i interpretar dades hidrogeològiques i hidroquímiques. Donat que la seva arquitectura és de codi lliure i obert, es pot actualitzar i ampliar segons les aplicacions personalitzades que cada usuari requereixi. La conceptualización de un sistema hidrogeológico implica el continuo monitoreo y evaluación de una gran cantidad de parámetros (e.g., parámetros hidráulicos). Con respecto a los parámetros hidráulicos, su cuantificación es uno de los problemas más comunes en los estudios hidrogeológicos. Es ampliamente reconocido que los métodos para obtener este tipo de parámetros tienen sus limitaciones y son dependientes de la escala de análisis. En este sentido, es necesario disponer de métodos y herramientas para estimarlos dentro de su contexto espacial y validar su incertidumbre cuando se aplican en una escala superior de análisis. Los datos recopilados y generados para realizar un modelo conceptual hidrogeológico a menudo se almacenan en diferentes escalas y formatos (e.g., mapas, hojas de cálculo o bases de datos). Este volumen de datos en continuo crecimiento requiere de herramientas y metodologías que mejoren su compilación y gestión para su posterior análisis. Las contribuciones realizadas son: (i) proporcionar metodologías dinámicas y escalables para migrar e integrar múltiples infraestructuras de datos (ya sean infraestructuras de datos espaciales y no espaciales, o la implementación de herramientas TIC); (ii) obtener un mayor rendimiento del análisis hidrogeológico teniendo en cuenta su contexto espacial; (iii) proporcionar herramientas específicas para analizar procesos hidrogeológicos y obtener parámetros hidráulicos que desempeñan un papel clave en los estudios de aguas subterráneas; y (iv) difundir software de código abierto y de fácil acceso que permita la estandarización, gestión, análisis, interpretación e intercambio de datos hidrogeológicos con un modelo numérico dentro de una única plataforma de información geográfica (SIG). Se ha diseñado una metodología dinámica y escalable para armonizar y estandarizar múltiples conjuntos de datos de diferentes orígenes, o bien para conectar éstas infraestructuras de datos con herramientas TIC. Esta metodología puede ser implementada en cualquier tipo de proceso de migración e integración de datos (DMI), para desarrollar infraestructuras de datos espaciales y no espaciales, o para implementar herramientas TIC en las infraestructuras de datos existentes para análisis adicionales; mejorando así la gobernanza de los datos. Un mayor rendimiento para obtener los parámetros hidráulicos del acuífero se ha abordado desde el desarrollo de una herramienta SIG. La interpretación de ensayos de bombeo dentro de su contexto espacial, puede reducir la incertidumbre de su análisis con un conocimiento preciso de la geometría y los límites del acuífero. Este software diseñado para recopilar, administrar, visualizar y analizar las pruebas de bombeo en un entorno SIG, apoya la parametrización hidráulica de los modelos de flujo y transporte de aguas subterráneas. Para mejorar la cuantificación de los parámetros hidráulicos, se ha realizado una compilación, revisión y análisis de la conductividad hidráulica basada en metodologías de tamaño de grano. Posteriormente, se ha considerado y discutido la incertidumbre de aplicar estos métodos en una escala mayor comparando los resultados de la mejora de escala con los obtenidos en ensayos de bombeo. Finalmente, se presenta una herramienta SIG libre, de código abierto y de fácil aplicación. Esta nueva generación de herramienta SIG pretende simplificar la caracterización de los cuerpos de agua subterránea con el propósito de construir modelos conceptuales ambientales rigurosos. Además, esta herramienta permite estandarizar, gestionar, analizar e interpretar datos hidrogeológicos e hidroquímicos. Gracias a su arquitectura de código libre y abierto, se puede actualizar y ampliar según las aplicaciones personalizadas que cada usuario requiera

Premi Extraordinari de Doctorat, promoció 2016-2017. Àmbit d’Enginyeria Civil The natural environment in which we live, is subjected, to a greater or lesser extent, to the pressure of human activity, with water being one of the most sensitive elements. For this reason, aware of this situation, from all the forums (Administration, Companies and stakeholders) is imposing the practice new standards unthinkable during the decades of industrial development, aimed at making the environment and industry compatible. A new model of mining seeks to achieve a balance between good environmental practices and efficiency, so that production is linked to environmental respect. The Niebla-Posadas aquifer (NP) constitutes one of the water resources within the Guadalquivir Basin, which supports traditional agriculture in the area and is the source of drinking water for many populations. In recent decades, competition for this resource has increased due to the expansion of irrigated agriculture and in turn affected by the development of mining activity with the opening of the Cobre Las Cruces mine (CLC). The CLC is one of Europe's largest open pit copper mine which has implemented pioneering water management methodologies in the mining industry. One of the highlights of this methodology is the Drainage and Reinjection system (DRS) for groundwater near the mining activity. The DRS allows the drainage of the groundwater before it can appear in the open pit, through a set of wells surrounding it. Moreover, once treated to meet environmental requirements, this water is reinjected into the aquifer through another set of wells surrounding the extraction wells. In addition, groundwater in the vicinity of the CLC presents poor natural quality, so they are unsuitable for direct use without previous treatment. High natural concentrations of some components, initially alerted the public opinion. Nevertheless, today it has been demonstrated that this is not due to mining activity but to natural processes. The general goal of this thesis is to provide a series of tools to improve the methodology of groundwater management in a mining environment. Development of a methodological framework is of great interest and may constitute a support tool for sustainable management and protection of groundwater resources affected by mining activities. All these methodological issues are focused on and applied to the CLC, which has allowed validation of joint use to ascertain and quantify the hydrodynamic aspects of the groundwater at mine sites and definition of the bases for sustainable water resource management in the area. El entorno natural en el que vivimos, se ve sometido, en mayor o menor medida, a la presión de la actividad humana, siendo el agua uno de los elementos más sensibles. Por esta razón, conscientes de esta situación, desde todos los foros (Administración, Empresas y stakeholders) se está imponiendo la práctica nuevos estándares impensables durante las décadas del desarrollo industrial, encaminados a lograr compatibilizar el medio ambiente y la Industrial (en especial, en esta tesis, la actividad minera). Un nuevo modelo de minería pretende lograr un equilibrio entre buenas prácticas ambientales y eficiencia, de forma que la producción está ligada al respeto ambiental. El acuífero Niebla-Posadas (NP) constituye uno de los recursos hídricos, dentro de la cuenca del Guadalquivir, que da apoyo a la agricultura tradicional de la zona y es la fuente de agua potable para varias poblaciones. En las últimas décadas, la competencia por este recurso se ha incrementado debido a la expansión de la agricultura de regadío y afectado a su vez por el desarrollo de la actividad minera con la apertura de la mina Cobre Las Cruces (CLC). CLC es una de las minas de cobre a cielo abierto más moderna e importante de Europa, donde se ha implementado unas metodologías de gestión de aguas pioneras dentro de la industria minera. Uno de los puntos fuertes de esta metodología es el Sistema de Drenaje y Reinyección (SDR) de las aguas subterráneas en el entorno de la actividad minera. El SDR permite drenar las aguas subterráneas antes de que puedan aflorar en la corta minera, mediante una serie de pozos construidos formando un anillo a su alrededor. Asimismo, estas aguas, una vez tratadas para cumplir los requerimientos ambientales exigidos, son reinyectadas al acuífero mediante otro conjunto de pozos que rodean los pozos de extracción. Las aguas subterráneas en las inmediaciones del CLC presentan mala calidad natural, de forma que resultan inapropiadas para su uso directo sin previo tratamiento. Las elevadas concentraciones naturales que algunos componentes presentaban, alertaron inicialmente a la opinión pública. No obstante, hoy ha podido demostrarse que esta no se debe a la actividad minera sino a procesos naturales. El objetivo principal de esta tesis es proporcionar una serie de herramientas que permitan mejorar la metodología de gestión de las aguas subterráneas en un entorno minero. Desarrollar este marco metodológico es de gran interés y puede constituir una herramienta de apoyo para la gestión sostenible y protección de los recursos hídricos subterráneos, en zonas afectadas por actividades mineras. La combinación de todos estos aspectos metodológicos se ha centrado y aplicado al caso CLC, lo que ha permitido: validar su uso conjunto con el fin de conocer y cuantificar los aspectos básicos de la hidrodinámica subterránea en un entorno minero complejo y definir las bases para una gestión sostenible de los recursos hídricos de la zona. L'entorn natural en què vivim, es veu sotmès, en major o menor mesura, a la pressió de l’activitat humana, sent els recursos hídrics un dels elements més sensibles. Per aquesta raó, conscients d’aquesta situació, des de tots els fòrums (administració, empreses i stakeholders) s’està imposant la pràctica de nous estàndards impensables durant les dècades del desenvolupament industrial, encaminats a aconseguir compatibilitzar el medi ambient i la industria. Un nou model de mineria pretén aconseguir un equilibri entre les bones pràctiques ambientals i eficiència, de manera que la producció està lligada al respecte ambiental. L'aqüífer Niebla-Posadas (NP) constitueix un dels recursos hídrics, dins de la conca del Guadalquivir, que dóna suport a l'agricultura tradicional de la zona i és la font d'aigua potable per varies poblacions. En les últimes dècades, la competència per aquest recurs s'ha incrementat a causa de l'expansió de l'agricultura de regadiu i afectat alhora pel desenvolupament de l'activitat minera amb l'obertura de la mina Cobre Las Cruces (CLC). CLC és una de les mines de coure a cel obert més moderna i gran d'Europa que ha implementat unes metodologies de gestió d’aigües pioneres dins de la indústria minera. Un dels punts forts d’aquesta metodologia és el Sistema de Drenatge i Reinjecció (SDR) de les aigües subterrànies a l’entorn de l’activitat minera. El SDR permet drenar les aigües subterrànies abans que puguin aflorar en la “Corta minera”, mitjançant una sèrie de pous al seu voltant. Alhora, aquestes aigües, un cop tractades per acomplir els requeriments ambientals exigits, són reinjectades al aqüífer mitjançant un altre conjunt de pous que envolten els pous d’extracció. A més, les aigües subterrànies a l’entorn de CLC presenten mala qualitat natural, de manera que resulten inapropiades pel seu ús directe sense tractament previ. Les elevades concentracions naturals que alguns components presentaven, van alertar inicialment a la opinió pública. No obstant, avui s’ha pogut demostrar que aquesta no es deu a l’activitat minera sinó a processos naturals. L'objectiu general d'aquesta tesi és proporcionar una sèrie d’eines que permeten millorar la gestió de les aigües subterrànies en un entorn miner. Desenvolupar aquest marc metodològic és de gran interès i pot constituir una eina de suport per a la gestió sostenible i protecció dels recursos hídrics subterranis en zones afectades per activitats mineres. Aquest marc metodològic inclou estudis hidrogeoquímics, isotòpics, estadístics relacionats amb les aigües subterrànies i la interacció aigua-roca, i modelació de flux i transport reactiu. La combinació de tècniques hidrogeoquímiques i isotòpiques, tant estables com radioactius, en les aigües subterrànies han permès: 1) Identificar dues agües amb característiques molt diferenciades: 1) Aqüífer Niebla-Posadas (NP): aigua jove amb baix grau de mineralització i composició bicarbonatada càlcica. Aquesta aigua s'utilitza per a fins agrícoles i de consum, i el seu ús està regulat per l'activitat minera; 2) Massa d’aigua Paleozoic: aigua amb major temps de trànsit, amb alt grau de mineralització i composició clorurada sòdica. Degut a la qualitat que presenten aquestes aigües, no es destinen de forma directa a cap ús d’abastament. A més, s’ha observat una evolució en la hidroquímica de l'aqüífer degut a la mescla entre les dues aigües i de reaccions com ara intercanvi catiònic, dissolució de calcita i oxidació de la matèria orgànica, etc. 2) Conèixer la taxa de renovabilitat dels recursos hídrics subterranis. S'ha estimat el temps de residència de les aigües subterrànies de l'aqüífer utilitzant 3H, 14C i 36Cl. La datació d'aquestes aigües ha permès la zonificació de l'àrea d'estudi en: zona de recàrrega ( 30 ka). 3) Identificar l’origen de certs compostos presents en les aigües subterrànies (amoni, arsènic i bor) i definir el seu origen natural o antropogènic. L'increment de NH4 i B s'interpreta com el resultat de la degradació de la matèria orgànica pel sulfat dissolt en l'aigua de recàrrega. Les altes concentracions d'arsènic en l'aigua subterrània és el resultat de la dissolució reductiva de mineralitzacions d’òxids de ferro (gossan) paleozoics rics en As deguda a l'oxidació de la matèria orgànica dissolta en l’aigua. Per tant, aquestes elevades concentracions s'atribueixen originalment a processos geogènics. Per altra banda l’aigua que s’acumula al fons de la “corta minera” (que ha estat en contacte amb el jaciment) requereix un tractament molt diferent ja que no està autoritzada ni el seu abocament ni reinjecció a l’aqüífer, servint com abastament principal del procés hidrometalúrgic. No obstant, l’Administració obliga a compensar la part de l’aigua que aflora al fons de la “corta” y que procedeix de l’aqüífer NP. L'ús de mètodes estadístics multivariants ha permès calcular, mes a mes, les proporcions de mescla de cadascuna de les aigües que composen l’aigua bombejada des del fons de la “corta minera” (aqüífer NP, Paleozoic o escolament). D'aquesta manera s'ha determinat el volum d'aigua extret de l'aqüífer Cenozoic que ha de ser compensat anualment, d'acord amb les condicions establertes per l’Administració. Award-winning

Groundwater can be used for cooling buildings. In summer, groundwater is cooler than the temperature of the atmosphere. Then, this water can be either circulated through heat exchangers. This is an enviromenally friendly system that may also be reserved and use groundwater for heating purposes during winter. Basic principles governing heat transport in aquifers are well known. It is widely accepted that heat is transported by advection and conduction. One would expect dispersion to be also a relevant mechanism for heat transport. Surprisingly, this mechanism is rarely accounted for in cooling studies. This may reflect uncertainties in how to represent dispersion, which is known to grow with the scale of the problem. If one adopts a large dispersivity (typical of large scale problems), then unrealistically too much heat is dispersed into the aquifer. On the other hand, if dispersion is neglected then one would not simulate accurately heat dissipation.

A l’àmbit de l’Àrea Metropolitana de Barcelona s’ha pogut observar durant els últims anys una pujada progressiva dels nivells freàtics. Aquest augment ha estat provocat pels canvis al cicle hidrològic, produïts per les variacions en el grau d’urbanització i en els usos del sòl i de les aigües. Tot això provoca problemes de filtracions en diverses estructures subterrànies, públiques i privades, amb un notable cost econòmic. Per pal·liar aquest problema la Universitat Pompeu Fabra (UPF) va implementar un sistema d’intercanvi de calor mitjançant l’explotació de les aigües subterrànies. Aquests sistema permet aprofitar les aigües del subsòl de la ciutat amb un doble objectiu: (1) aconseguir una alternativa de subministre energètic pels sistemes de refrigeració / calefacció de la pròpia Universitat i (2) mitigar els problemes locals causats per la recuperació de nivells freàtics durant els últims anys. L’Agència Catalana de l’Aigua ha requerit a la UPF a avaluar els impactes potencials que aquesta explotació pot provocar sobre els aqüífers de la zona i a definir, si s’escau, les possibles mesures correctores.

Realització d'un estudi hidrogeològic en detall de les rodalies de la futura estació de Foneria de la Línia 9, Barcelona, per buscar alternatives constructives a la solució proposada en el projecte. Posteriorment es realitza i calibra un model numèric que permet simular i validar les alternatives proposades

Históricamente, los alrededores del delta del río Besòs sufrían problemas a causa del alto nivel piezométrico, pues durante la industrialización de la zona se van a extraer grandes caudales de agua de sus acuíferos y una vez estos caudales se han dejado de extraer, los niveles piezométricos han aumentado para alcanzar valores próximos a su cota antigua natural. Gracias a que ya existe una base de datos que contiene la información existente hasta la fecha del delta del río Besòs, y que permite añadir los datos que se generan con las perforaciones de los nuevos proyectos que se están llevando a cabo en la zona, es posible construir un modelo geológico tridimensional, para facilitar el conocimiento de las zonas del delta menos estudiadas. Para integrar la interpretación geológica en el modelo tridimensional se han desarrollado un conjunto de herramientas sobre la plataforma ArcGIS. Estas herramientas permiten plasmar en un plano bidimensional la interpretación del geólogo y llevarla al espacio tridimensional para la construcción del modelo 3D.