The Cenomanian (Upper Cretaceous) sedimentary rocks of the External Prebetic (Betic Cordillera) in the Sierra de Montearagón-Carcelén (SE Spain) record the transgression and flooding of continental deposits and the subsequent development of an inner shallow carbonate platform. The transgressive surface is densely colonized by infaunal trace-makers of the Glossifungites ichnofacies (Gastrochaenolites and Glossifungites), which indicate sediment starvation and erosion as well as colonization of a firmground. The first deposits were a thick calcarenite bar (2 to 11 m) with large-scale cross-bedding pointing to a high-energy environment in a shallow carbonate platform. The record of the Rosselia ichnofacies (Rosselia and Ophiomorpha) confirms a loose sandy bottom under high-energy conditions. The overlaying stratigraphic succession is characterized by subtidal laminated marly limestones and intertidal limestones with rhizoliths interpreted as a mangrove swamp environment. These facies are organized in shallowing-upwards sedimentary sequences. An episodic high-energy event is represented by bivalve-rich limestones representing shell lags of disarticulated valves. This facies could be related to a climatic perturbation evidenced by a negative excursion of δ13C and δ18O. The successive shallowing-upwards sedimentary sequences persisted thanks to subsidence related to the tectonically controlled depocenters located in the south of the Sierra de Montearagón-Carcelén. The differential subsidence, evidenced by the increasing thickness towards the south of the sector under study, suggests the activity of listric faults that controlled the depocenters. This is the first report of the Cenomanian transgression in this sector of the External Prebetic and the first record of the very extensive mangrove swamp that developed close to the land that emerged.

In times of population growth, climate change, and increasing water scarcity around the world, it is important to take an objective look at water, a fundamental resource for life. Hydrodynamic modeling makes possible the research of different aspects of the water cycle and the evaluation of different hydrological and hydrogeological forecasting scenarios in the short and medium terms. The present research offers a more detailed scope at the hydrodynamic processes and their space-time distributions on a UE pilot in the Júcar River Basin, providing a calibrated and validated hydrodynamic model of 121 km river reach for 45 years period (1974–2019) on a daily scale. The obtained information is about discharge and water depths along the Júcar River reach within the hydrogeological boundaries of the Mancha Oriental Aquifer (MOA). The river–aquifer interactions have been represented as dynamic boundary conditions expressed as a difference between observed discharges measured in 3 gauging stations. The obtained calibration error performance evaluations of observed and simulated values cover two periods, according to observed data availability from gauging station 08036 with resulting R2 for both discharges and water depths over 0.96. The model validation results were obtained for a different gauge 08132 and the determination coefficients R2 also perform very well with value of 0.90. The model developed might be useful for decision making in water resources management and can be used to generate simulated time series of water depths, levels, discharges, and velocities in reaches where gauging measurements are not available with a desired space-time resolution (from meter/second to kilometer/month). Estimation of critical discharge value (1.973 m3s−1) for system equilibrium, based on the balance between losing and gaining sub-reaches of the river, is also made with a statistical significance at 95% for hydrologic years 2007–2010, period influenced by restrictions in groundwater withdrawals. The results of the present research are important for the proper and objective management of the scarce water resources on a watershed scale in Júcar River Basin, a complex case study representing semiarid climate, growing anthropogenic pressures, and complex river–aquifer interactions. The used approach of dynamic representation of the river–aquifer interactions as distributed source boundary condition in the one-dimensional hydrodynamic model might be applied in another study case on similar scale.

Pétrola Lake in southeast Spain is one of the most representative examples of hypersaline wetlands in southern Europe. The rich ecosystem and environmental importance of this lake are closely associated with the hydrogeological behaviour of the system. The wetland is fed by the underlying aquifer with relatively fresh groundwater—1 g L−1 of total dissolved solids (TDS)—with a centripetal direction towards the wetland. In addition, the high evaporation rates of the region promote an increase in the concentration of salts in the lake water, occasionally higher than 80 g L−1 TDS. The density difference between the superficial lake water and the regional groundwater can reach up to 0.25 g cm−3, causing gravitational instability and density-driven flow (DDF) under the lake bottom. The objective of this study was to gain an understanding of the geometry of the freshwater–saltwater interface by means of two-dimensional mathematical modelling and geophysical-resistivity-profile surveys. The magnitude and direction of mixed convective flows, generated by DDF, support the hypothesis that the autochthonous reactive organic matter produced in the lake by biomass can be transported effectively towards the freshwater–saltwater interface areas (e.g. springs in the lake edge), where previous research described biogeochemical processes of natural attenuation of nitrate pollution.

Saline lakes are mostly located in endorheic basins in arid and semi-arid regions, where the excess of evaporation over precipitation promotes the accumulation of salts on the surface. As the salinity of these lakes increases, their mass balance changes, and biogeochemical processes may be intensified. In that sense, Pétrola Lake (SE Spain) is a terminal lake located in an endorheic basin with elevated anthropic pressure, mainly derived from agricultural inputs and wastewater discharge. The goal of this study was to evaluate the interaction between groundwater and saline water from Pétrola Lake to improve our knowledge of groundwater recharge processes by density-driven flow (DDF) in terminal lakes. A combination of hydrochemical (chloride concentration) and stable isotope (δ18OH2O and δ2HH2O) data were used. In order to test the conceptual model, a simple numerical experiment was performed using a one-dimensional column that represents the relationship between the lake and the aquifer incorporating the variable density coupling control in solute migration. The isotopic composition of 190 groundwater and surface water samples collected between September 2008 and July 2015 provides a regression line (δ2HH2O = 5.0·δ18OH2O − 14.3‰, R2 = 0.95) consistent with dominant evaporation processes in the lake. The DDF towards the underlying aquifer showed a strong influence on the mixing processes between the groundwater and surface water. Nevertheless, groundwater chemistry at different depths beneath the lake remains almost constant over time, suggesting an equilibrium between DDF and regional groundwater flow (RGF). Modelling isotope changes allowed inferring the temporal pattern of saline water recharge, coinciding with the summer season when water loss through evaporation is most significant. Consequently, the transport of solutes suitable for chemical reactions is then feasible to deeper zones of the aquifer.

Lake Alboraj, located in southeast Spain, was declared natural Microreserve and included into European Natura-2000 Network due to its contribution to environmental heritage. Unfortunately, the ecological status of the lake has changed dramatically, mainly due to the lowering of water table caused by groundwater abstractions for irrigation. It is a permanent small karstic lake whose surface has reduced in the last decades to nearly the third part of its historical water level. The water column shows a marked seasonal oxycline, that splits an aerobic upper layer (epilimnion) from an anaerobic layer below (hypolimnion). Sequencing 16S rRNA gene amplicons and applying chemical tools at epilimnion, hypolimnion and sediment, showed a clear gradient in the bacterial community structure, which support the co-existence of assimilatory and dissimilatory microbial mediated reactions. Results allows to infer that microbial stratification could provide various physical and chemical environments at different depths in the water column related to biogeochemical reactions providing N-S-C- recycling processes.

The cathedral of Santa Maria, where the Munoz Chapel is located, is the most remarkable monument of the UNESCO Wold Heritage City of Cuenca (Spain). This emblematic chapel suffers an intense stone weathering by crystallization of a complex mixture of salts including epsomite, hexahydrite, gypsum, chlorides and phosphates. The salt dynamics is controlled by a variable indoor environment with daily and seasonal cyclicality. A methodology combining salt analysis, environmental monitoring and non-destructive stone inspection was adopted in order to understand the salt crystallization dynamics and finally, to design an adapted preventive conservation plan focused on the mitigation of the salt damages. Moreover, new parameters are designed in order to quantify the microenvironmental variability, establishing a new methodology for the analysis of indoor environments. Obtained results reveal that stone weathering is mainly due to: (1) the transformation of both CaSO4 and MgSO4.4H(2)O into CaSO4.2H(2)O and MgSO4.6H(2)O, respectively; and (2) the direct crystallization of MgSO4.6H(2)O in the porous system. Thesephases crystallize as efflorescences and as subflorescences, causing granular disintegration, peeling and scaling on the stone. Several preventive measures are finally proposed, being focused on two main objectives: (1) reducing the access of salts and moisture to the monument; and (2) establishing a nonaggressive environment, keeping temperature and relative humidity constants in the range of 15-20 degrees C and 40-50%, respectively. This proposed climate range is defined in order to avoid both the crystallization of new salts in the porous system of the stone as well as volume changes of the present salts. This study constitutes a pilot project where to test the efficiency of these preventive measures that could be extensive to the whole cathedral complex. (C) 2020 Elsevier Masson SAS. All rights reserved.

The objective of this study was to analyse periodicities and the long‐term variability of monthly Júcar River–Mancha Oriental Aquifer interactions (RAI) and regionally measured precipitation (PP) with special focus on the correlations between these local hydrological variables and the large climatic patterns governing the Iberian Peninsula, represented by their teleconnection indices – the North Atlantic Oscillation index (NAOi) and the Western Mediterranean Oscillation index (WeMOi). To that end, wavelet analysis has been applied since it not only provides insight into the time‐series dynamics but also permits statistical interpretation and correlation analysis. As a result, several periodicities have been detected: intermittent semi‐annual periodicity in PP and the NAOi and annual periodicity in the RAI, NAOi and WeMOi time series. Long cycles (approximately 14 years) are also observed in the PP and WeMOi time series. The cross‐wavelet spectra show a correlation between the RAI and the rest of the variables on the semi‐annual and the annual scales, while wavelet coherence detects common behaviour with longer cycles – 5–6 years between the NAOi and the RAI and cycles of both 1–5 years and 7–10 years between PP and the RAI. Furthermore, results show that the periodicities in the teleconnection indices and precipitation propagate into the RAI with certain lead times: 3 months between the RAI and PP and 6 months between the RAI and the NAOi. The results indicate that the detected periodicities and the coherence between the studied variables could have applications in strategic planning on a river basin scale, taking into account the propagation times and the frequency scale. This methodological approach can be applied into strategic water resource planning independently of the geographical location of the hydrogeological system, the basin size and the climate region.

The sustainability of groundwater abstractions for irrigation practices must be monitored to achieve a long-term equilibrium in aquifers. The accounting of irrigation water requirements in river basin management plans is commonly and mainly calculated by combining the average multiannual irrigated surface estimates and the unitary crop water requirements. However, remote sensing approaches allow water managers to incorporate more dynamic knowledge of a territory by monitoring irrigated crops. Hence, time series of biophysical products processed from Earth Observation data for 4 years (2010–2013) were incorporated into a remote sensing-based soil water balance to estimate spatially distributed irrigation water requirements on a monthly time scale over a semiarid environment, where agricultural practices greatly depend on groundwater resources. The simulated monthly water abstractions were then evaluated regarding monthly groundwater level changes recorded from a piezometric network. The results indicated that groundwater level changes on a monthly scale could be explained in more than 75% of the cases. Therefore, a simple remote sensing-based approach brings temporally and spatially distributed information of great practical value to river basin water managers according to their management necessities.

Groundwater flow models have been increasingly used to support policy making. A substantial amount of research has been dedicated to improving, validating and calibrating models and including stakeholders in the modelling process. However, little research has been done to analyze how the choices of model makers and steering by policy makers result in models with specific characteristics, which only allow specific modelling outcomes, and how the use of these modelling outcomes leads to specific social, economic and environmental consequences. In this study, we use the social construction of technology framework to explore the development, characteristics and uses of the groundwater model of the Mancha Oriental aquifer in Spain. The specific characteristics and functioning of this model influenced the policy implementation, implying that involving stakeholders in the development and use of models is crucial for improved democratic policy making.

Pétrola Lake is a terminal lake located in the discharge zone of an endorheic basin. Terminal lakes may be responsible for a significant amount of recharge from evaporated saline water, increasing the salinity of the shallow groundwater. The purpose of this paper is to evaluate the interaction between groundwater and saline water from Pétrola Lake in order to improve the knowledge of groundwater recharge processes by density-driven flow (DDF) in terminal lakes. To achieve this goal, hydrochemical (chloride concentration) and stable isotope (δ18O and δDH2O) data were used. The isotopic composition of 190 groundwater and surface water samples collected between September 2008 and July 2015 provide a regression line (δDH2O = 5.0·δ18O – 14.3‰, R2 = 0.95) consistent with dominant evaporation processes. In the basin, groundwater recharge is mainly produced by Atlantic-derived precipitation. In the lake, isotope data suggested that the loss of water occurred at humidity values between 60% and 75%. The saline boundary layer is formed at elevated salt concentrations. Leakage from the lake to the underlying aquifer would take place with salinities from 1.24 g/cm3 by means of the DDF. This study contributes to better understand the role of DDF in terminal lakes.

This work shows the technical feasibility of incorporating phase change materials (PCMs) into clay plastering mortars to improve the thermal properties of the building envelopes. Due to the absence of regulated and internationally agreed-upon norms for clay mortars containing thermoregulating microcapsules (MPCMs), two tests following UNE-EN-998-1:2010 and UNE-EN-1015, were designed to provide the greatest similarity to its final application. Three different dosages 5, 10, and 15 wt% of MPCM relative to the dried mortar weight were used. Fresh mortars were physically characterized to determine its consistency, apparent density, period of workability and open time, and occluded air content. Physical and mechanical characteristics were determined for hardened mortar. The thermal characteristics of the specimens were analysed by using a differential scanning calorimetry, obtaining their apparent specific heat capacities and the enthalpy curves. Building simulation software is a fundamental tool for designing buildings with almost zero energy consumption. In this study, three identical architectural models were simulated. The reference building had inner coatings of clay-based mortar, mortar with 15% added material, and a conventional gypsum mortar. These buildings were subjected to the same exposure and radiation conditions, which allowed the result to be compared to evaluate the effect of incorporating the PCM.

Endorheic or closed drainage basins in arid and semi-arid regions are vulnerable to pollution. Nonetheless, in the freshwater-saltwater interface of endorheic saline lakes, oxidation-reduction (redox) reactions can attenuate pollutants such as nitrate (NO3-). This study traces the ways of nitrogen (N) removal in the Pétrola lake-aquifer system (central Spain), an endorheic basin contaminated with NO3- (up to 99.2mg/L in groundwater). This basin was declared vulnerable to NO3- pollution in 1998 due to the high anthropogenic pressures (mainly agriculture and wastewaters). Hydrochemical, multi-isotopic (δ18ONO3, δ15NNO3, δ13CDIC, δ18OH2O, and δ2HH2O) and geophysical techniques (electrical resistivity tomography) were applied to identify the main redox processes at the freshwater-saltwater interface. The results showed that the geometry of this interface is influenced by land use, causing spatial variability of nitrogen biogeochemical processes over the basin. In the underlying aquifer, NO3- showed an average concentration of 38.5mg/L (n=73) and was mainly derived from agricultural inputs. Natural attenuation of NO3- was observed in dryland farming areas (up to 72%) and in irrigation areas (up to 66%). In the Pétrola Lake, mineralization and organic matter degradation in lake sediment play an important role in NO3- reduction. Our findings are a major step forward in understanding freshwater-saltwater interfaces as reactive zones for NO3- attenuation. We further emphasize the importance of including a land use perspective when studying water quality-environmental relationships in hydrogeological systems dominated by density-driven circulation.

La Laguna de Petrola (SE Albacete) es uno de los humedales de mayor singularidad de Castilla-La Mancha, en especial por sus caracteristicas geomorfologicas, hidrologicas y quimicas (aguas sulfatado-magnesicas). Esta declarada Reserva Natural, Refugio de Fauna y es un LIC englobado en la ZEPA E153. Los humedales salinos asociados a zonas agricolas de regiones aridas y semiaridas se consideran zonas vulnerables a la contaminacion agricola (p. e. nitrato, metales pesados ligados a fertilizantes, pesticidas). Esta laguna hipersalina se encuentra eutrofizada debido a los aportes de nutrientes. Estos aportes derivan principalmente de fertilizantes amoniacales, asi como de las aguas residuales urbanas que se vierten sin tratamiento directamente en el vaso lagunar. En el sistema salino se ha identificado la presencia de procesos de reduccion de nitrato y sulfato que pueden atenuar la contaminacion de origen antropico. Estos procesos se ven favorecidos por la confluencia de: i) la presencia sedimentos ricos en materia organica en el fondo del lago; ii) condiciones anaerobias bajo la interfase agua-sedimento; iii) niveles elevados de carbono organico disuelto en las aguas superficiales. En el presente estudio se describen brevemente los principales procesos biogeoquimicos identificados en el sistema.

El acuifero de la Mancha Oriental es uno de los mas extensos del Sur de Europa 7,260 km2 . Se localiza en el extremo occidental de la Llanura Manchega y pertenece en su totalidad a la cuenca del Rio Jucar. Desde tiempos remotos se tiene constancia de la existencia de una superficie piezometrica con cotas superiores a la superficie. De hecho, la Villa de Albacete sufria inundaciones con elevada frecuencia, lo que propicio que, a principios del siglo XIX se realizaran las obras del Canal de M.a Cristina con el objeto de descargar las aguas de las tierras encharcadas hacia al rio Jucar. Estos antecedentes hicieron que hace medio siglo la Mancha Oriental fuera objeto de especial atencion por parte de la Administracion del Estado. A partir de los estudios realizados se obtuvieron los primeros datos que confirmaban el potencial hidrogeologico de la zona. Desde entonces, la Mancha Oriental sufrio una transformacion socioeconomica debida al desarrollo del regadio mediante la explotacion de las aguas subterraneas. El aumento progresivo de las extracciones de agua subterranea por encima de la capacidad de recarga provoco cambios notables en el flujo subterraneo y por tanto en las relaciones entre el acuifero y el rio. Durante este periodo se han sucedido situaciones como: la entrada en vigor de la ley de aguas, dos procesos de planificacion hidrologica, la sustitucion de bombeos con aguas superficiales e incluso la primera Oferta Publica de Adquisicion de Derechos de Agua de Espana. Todos estos aspectos han sido estudiados desde diversos equipos de investigacion orientados hacia el conocimiento y la gestion de los recursos hidricos. Este conocimiento ha permitido a este grupo elaborar un modelo de flujo de agua subterranea en tres dimensiones calibrado y validado, capaz de simular y cuantificar escenarios futuros de gestion y cambio climatico para el acuifero Mancha Oriental.

Sulfur (S) plays a significant role in saline environments, and sulfate (SO42 −) is an important component of the biogeochemical S-cycle since it acts as the main electron acceptor in anoxic sediments. The purpose of this paper is to evaluate the fate of S, its origin, and processes affecting sulfate outcome in the hypersaline Pétrola Lake in the Castilla-La Mancha region (High Segura Basin, SE Spain). The lake is the terminal discharge zone of an endorheic basin with considerable anthropogenic pressures. Anthropogenic activities (mainly agricultural inputs and wastewater discharge), together with bedrock leaching of sulfate and sulfide-rich sediments, increase dissolved SO42 − in surface and groundwater up to 123,000 mg/L. The source and fate of sulfate in this environment was investigated coupling hydrochemistry, including hydrogen sulfide (H2S) microprofiles, isotopic analyses (δ34S, δ18OSO4, δ2HH2O, δ18OH2O, and tritium), mineralogical determinations, and molecular biology tools (16S rDNA amplification and sequencing). The origin of dissolved SO42 − in water is related to pyrite oxidation from Lower Cretaceous sediments, and secondary gypsum dissolution. Under the lake, dissolved SO42 − decreases with depth, controlled by three main processes: (1) seasonal evaporation cycles, (2) hydrodynamic instability caused by the different density-driven groundwater flow, and (3) sulfate-reduction processes, i.e. dissimilatory bacterial sulfate reduction (BSR). These processes control the continuous recycling of sulfur in the system. Lake water and groundwater are in hydraulic connection, and a density-driven flow (DDF) is able to transport reactive organic matter and dissolved SO42 − towards the underlying aquifer. Hydrochemical evolution in depth, H2S production (up to 0.024 nmol/cm3·s) and the presence of sulfate-reducing bacteria suggest the existence of BSR processes. However, isotope techniques are insufficient to elucidate BSR processes since their isotopic effect is masked by low isotope fractionation and high SO42 − concentrations. The pattern here described may be found in other saline basins worldwide.

Agricultural pollution and wastewater effluents from the village of Pétrola cause a high pressure over Pétrola Lake-aquifer system (Central Spain). The lake is rich in sulfate (SO42−), with concentrations up to 1,280 mmol/L. Pétrola lake is considered one of the most symbolic saline wetlands in Castilla-La Mancha Region, due to its geomorphology, hydrology and salinity (up to 109.4 mS/cm). At the water-sediment interface anaerobic conditions and high dissolved organic carbon (up to 21.5 mmol/L) and sulfide production (up to 5 nmol/L) suggest the development of bacterial sulfate reduction processes (BSR). Hydrochemical and isotopic results confirm a mixing trend between high density brine water from the lake and freshwater from the regional groundwater flow. The sulfur origin in the system seems to be linked to sulfide oxidation of Lower Cretaceous sediments (Utrillas Facies) that are rich in sulfide and organic matter. Sulfur and oxygen isotope data show the sulfate-bearing mineral dissolution as the main source of SO42− in surface water. The study concludes that the regulation of the amount of sulfur depends on the relationship between the kinetics of BSR and the hydrodynamic instability driven by the different density of groundwater flow.