Assesing the hydrogeological functioning of an evaporite karst system coupling tritium and physicochemical data

Discharge rate, electrical conductivity and water temperature have been continuously recorded in an evaporite karst spring located in S Spain and 3H determinations of spring water were performed. Results evidence a complex hydrogeological functioning, including rapid conduit flows (unsaturated zone), and diffuse flow (saturated zone) with diverse residence time within the systemUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech International Atomic Energy Agency (IAEA

Geochemical evolution of groundwater in an evaporite karst system: Brujuelo area (Jaén, Spain)

Chemical evolution of groundwater along two main flowpaths was studied in Brujuelo area, an evaporite plateau characterized by the presence of wetlands and drained by hyper-saline springs. Major ions were analyzed, saturation indexes of the main mineral species were computed, and inverse geochemical modeling was performed. Results show a relationship between elevation and water mineralization, indicating that drainage at higher altitude (brackish water) may be associated to gravity-driven flows while lower altitude springs could drain regional groundwater flows (brine water). Modeling results strongly support the hypothesis that most of the selected springs geochemically evolve in a common (S-N) flowpath.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Combining different tracers (CFC-12, 3H, 3He, 4He) to understand the hydrogeological functioning of a semiconfined aquifer.

The hydrochemical results obtained in a semiconfined aquifer called Niebla-Posadas aquifer (S of Spain) show an increase in mineralisation and δ13C in the flow direction, suggesting increasing residence time in the aquifer. However, different agricultural contaminants associated with recently infiltrated waters appear in the confined section. The combination of different groundwater-age tracers (CFC-12, 3H, 3He, 4He) provides valuable information to understand the hydrogeological processes and water quality intending to achieve proper water supply management. The preliminary result of tracers suggests that samples may be a mixture of a majority of tritium-free old groundwater and a minor fraction of recently infiltrated water.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Studying hydrogeochemical processes to understand hydrodiversity and the related natural and cultural heritage. The case of Los Hoyos area (South Spain)

The protection of geodiversity has been gaining interest during the last decades. However, the study of hydrodiversity has been much less developed than other aspects of the geological heritage (lithology, mineralogy, geomorphology, palaeontology). The objective of this work is to help with an inclusive definition of hydrodiversity by assessing its importance as part of geodiversity and how it can condition the natural and cultural heritage of a region. To that end, we have selected as a study area an evaporitic karst enclave of great geomorphological and environmental value located in southern Spain, named Los Hoyos, where diverse water features are found. Based on the hydrochemical and isotopic analysis of the water points, five main processes explain the hydrodiversity of the area: (1) the availability of minerals in the environment, (2) the residence time of groundwater, (3) the evaporation of water in the wetlands, (4) the common-ion effect (5) and the high ionic strength of groundwater. All these processes, directly related to the geology and geomorphology of the area (geodiversity), have given rise to diverse ecosystems (including protected wetlands), which enhance local biodiversity and geological forms (travertines), and are connected to the area's cultural heritage (salt extraction from the Paleolithic). This hydrodiversity is partially or totally responsible for a series of services to society related to its intrinsic, cultural, aesthetic, economic, functional, and scientific values. The case here presented exemplifies the importance of hydrodiversity in the natural and cultural heritage and highlights the need of advancing on the definition, promotion and protection of the hydrological heritage.This work was supported by the Autonomous Government of Andalusia (Junta de Andalucía) [grant numbers P11-RNM-8087, P10-RNM-6895R and P20-01118] and the LifeWatch ERIC call of the European Regional Development Fund [grant number LIFEWATCH-2019-04-AMA-01]. Funding for open access charge: Universidad de Málaga / CBUA

Características hidroquímicas de humedales salinos andaluces situados en distintos contextos hidrogeológicos

Póster. Comunicación científicaBuena parte de los humedales se encuentran relacionados con acuíferos de su entorno, hasta el punto de que su génesis y funcionamiento hídrico depende, en gran medida, de las aguas subterráneas (Linares, 2008). Por consiguiente, la calidad química de las aguas de los acuíferos determina de forma notable la de los humedales. No obstante, otros procesos hidrológicos, como la recarga superficial y la evaporación, juegan también un papel significativo en la hidroquímica de las lagunas (Custodio, 2001). Por ello, los aspectos hidrológico-hidrogeológicos son imprescindibles para entender el funcionamiento hídrico de los humedales y fundamentar en ellos otro tipo de estudios (ecológicos, botánicos, zoológicos). Con el fin de mejorar el conocimiento existente sobre de la influencia que ejercen los contextos geológico e hidrológico de los humedales sobre la composición química de sus aguas, se han seleccionado 20 lagunas andaluzas, repartidas entre las provincias de Málaga, Córdoba y Jaén, para su caracterización hidroquímica. Dichos humedales están asociadas a dos contextos geológicos distintos: los materiales arcilloso-evaporíticos pertenecientes a los Complejos Caóticos Subbéticos –CCS- (12 humedales) y los sedimentos detríticos aluviales que conforman el Paraje Natural de la Desembocadura del Río Guadalhorce, Málaga (8 humedales). Se han recogido y analizado en total 231 muestras, provenientes de las distintas laguanas, entre septiembre de 2014 y septiembre de 2016. Los análisis realizados incluyen la determinación de la alcalinidad total (HCO3- + CO32-) y de la concentración de iones mayoritarios (Cl-, SO42-, Na+, Ca2+, Mg2+, NO3-) y algunos minoritarios (Br-, K+, NH4+ y Li+). Los resultados obtenidos indican que las facies hidroquímicas predominantes en las aguas de los humedales de interior son las de tipo clorurada-sódica, sulfatada-cálcica y, en algunos casos, mixtas. Ello es debido a la presencia de minerales muy solubles (yeso y halita) en los materiales arcilloso-evaporíticos sobre los que se ubican los humedales, que favorecen la incorporación de Cl-, SO42-, Na+ y Ca2+ a las aguas subterráneas. Por su parte, los humedales costeros presentan aguas de facies clorurada-sódica exclusivamente, así como una mayor proporción de Mg2+ frente a Ca2+, debido a la influencia del Mar Mediterráneo en el acuífero aluvial que los alimenta. Las muestras de agua de las lagunas asociadas a los CCS presentan valores de la relación rCl-/Br- comprendidos entre 250 y 10.400, los cuales aumentan, de forma general, paralelamente a la mineralización. Esto podría atribuirse al aporte de Cl- producido por la disolución de halita (Kloppmann et al., 2001). Así mismo, algunas de estas muestras de agua presentan un enriquecimiento en Br- respecto a la línea teórica de disolución de la halita, debido a la precipitación de NaCl por evaporación (Alcalá y Custodio, 2008). Los valores de rCl-/Br- de las muestras de las lagunas costeras se sitúan entre 600 y 750, muy próximos al valor medio del agua de mar (655; Davis et al., 1998), lo que reflejaría la influencia marina sobre la composición química de las aguas de dichos humedales. Además, el conjunto de lagunas estudiadas ofrece un amplio rango de mineralización (hidrodiversidad), con aguas que contienen desde varias decenas de mg/l de Cl- (dulces) hasta otras que tienen decenas o cientos de miles de mg/l de Cl- (hipersalinas). En este trabajo se pone de manifiesto la notable influencia que ejerce el contexto geológico (geodiversidad) sobre la hidroquímica (hidrodiversidad) de los humedales andaluces, muchos de ellos de gran valor ambiental y que, a su vez, dan lugar a una importante variedad de hábitats. Ello les permite albergar una gran diversidad biológica, entre las que se incluyen especies de avifauna tan emblemáticas como el flamenco rosa (Phoenicopterus roseus), la malvasía cabeciblanca (Oxyura leucocephala) o el águila pescadora (Pandion haliaetus).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Contexto hidrogeológico y aproximación al balance hídrico de las lagunas Amarga y de los Jarales (Lucena, Córdoba)

La génesis de las lagunas Amarga y de Los Jarales (Lucena, Córdoba) está asociada a la karstificación de los materiales arcilloso-evaporíticos triásicos (Keuper) del Complejo Caótico Subbético (CCS). Con objeto de determinar el grado de relación entre las aguas subterráneas y las lagunas se han efectuado (1) un registro limnimétrico automatizado y un control climático en sus inmediaciones que ha permitido cuantificar las componentes de entrada (precipitación y escorrentía) y salida (evaporación) de los humedales, y (2) campañas de piezometría para caracterizar el sentido de los flujos subterráneos. La morfología de la cubeta de la laguna de Los Jarales se ha precisado a partir de datos LiDAR. Finalmente, se han simulado las evoluciones limnimétricas de ambas lagunas, utilizando diferentes métodos para el cálculo de la escorrentía. Los resultados obtenidos han permitido precisar los balances hídricos de ambos humedales durante varios años secos y constatar que la relación humedal-agua subterránea influye sobre la dinámica de las dos lagunas, aunque en distinto grado. Un control hidrometeorológico más prolongado ayudaría a profundizar en el conocimiento del funcionamiento hídrico de ambas lagunas, lo que facilitaría las tareas de gestión y conservaciónUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Atazanavir-Based Therapy Is Associated with Higher Hepatitis C Viral Load in HIV Type 1-Infected Subjects with Untreated Hepatitis C

Comunicación cortaWe assessed the relationship between atazanavir (ATV)-based antiretroviral treatment (ART) and plasma hepatitis C virus (HCV) viral load in a population of HIV/HCV-coinfected patients. HIV/HCV-coinfected patients who received ART based on a protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI) were included. Patients were stratified by ART drug [ATV/rtv, lopinavir (LPV/rtv), efavirenz (EFV), nevirapine (NVP), and other PIs], HCV genotype (1/4 and 2/3), and IL28B genotype (CC and non-CC). The Kruskal-Wallis test and chi-squared test were used to compare continuous and categorical variables, respectively. Multivariate analysis consisted of a stepwise linear regression analysis. Six hundred and forty-nine HIV/HCV-coinfected patients were included. HCV genotype 1/4 patients who received ATV had higher HCV RNA levels [6.57 (5.9-6.8) log IU/ml] than those who received LPV [6.1 (5.5-6.5) log IU/ml], EFV [6.1 (5.6-6.4) log IU/ml], NVP [5.8 (5.5-5.9) log IU/ml], or other PIs [6.1 (5.7-6.4) log IU/ml] (p=0.014). This association held for the IL28B genotype (CC versus non-CC). The association was not found in patients carrying HCV genotypes 2/3. The linear regression model identified the IL28B genotype and ATV use as independent factors associated with HCV RNA levels. ATV-based therapy may be associated with a higher HCV RNA viral load in HIV/HCV-coinfected patients

Monitoring and preliminary analysis of the natural responses recorded in a poorly accessible streambed spring located at a fluviokarstic gorge in Southern Spain

The analysis of natural responses (hydrodynamic, hydrothermal and hydrochemical) of karst springs is a well-established approach to provide insights into the hydrogeological functioning of the aquifers that they drain. However, a suitable monitoring program of these responses are often difficult to launch in poorly accessible streambed springs, due to the mixing between surface water and groundwater, in addition to topographic impediments. This work describes the installation procedure of the measurement equipment and the preliminary hydrogeological dataset collected at the Charco del Moro spring (Southern Spain) during one year. This outlet emerges 5 m below water surface, at the bottom of a partially flooded 20 - 200 m deep and 2 km long gorge, eroded by the Guadiaro River streamflow. It is considered the largest discharge point in the region, draining groundwater from northern nearby carbonate outcrops, although its catchment area is not established yet. Continuous (hourly) monitoring of electrical conductivity, water temperature, turbidity and water level (discharge) reflects a high degree of heterogeneity in the duality of groundwater flow and storage dynamics, which is typical of karst conduit flow systemsUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Hydrogeological characterization of the Salinas-Los Hoyos evaporitic karst (Malaga province, S Spain) using topographic, hydrodynamic, hydrochemical and isotopic methods

The Salinas-Los Hoyos karst system is a geological diapiric structure formed by materials of diverse nature (clays, sandstones, evaporites, volcanic rocks, dolostones, etc.) placed between Malaga and Granada provinces (S Spain). The abundance of evaporite rocks (gypsum, anhydrite and halite) and their high solubility contribute to the development of exokarstic features (dolines, uvalas, sinkholes). Grande and Chica lakes are dolines located in the western border of the diapir that are intersected by the piezometric level. Close to the first wetland is the Aguileras spring, which is the main discharge point of the west sector of the system. To assess the wetland-spring relation and the general functioning of the system, the geomorphologic framework has been analyzed and hydrogeological controls have been performed, consisting in limnimetric and discharge logging and in situ measurements of physico-chemical parameters (EC and water temperature). Furthermore, spring, wetland and rain water samples have been taken for subsequent chemical and isotopic analysis. Preliminary results show that wetland water level and spring discharge follow a similar trend, consistently with the inertia of the system. However, their hydrochemical evolution and isotopic values differ, thus wetland groundwater interaction has not been fully determined. Nevertheless, present research suggests that the hydrogeological connection would be more likely during wet periods, when the water table is at higher altitude.Key words: Evaporitic (karst) aquifer, Hydrological and hydrogeological behaviours, Natural responses, South Spain, Wetlands

Towards a better understanding of flow-related processes in the vertically distributed compartments of karst aquifers by combining natural tracers and stable isotopes

Understanding infiltration pathways throughout the different compartments of karst systems (soil-epikarst-unsaturated zone-saturated zone) is vital to assess recharge processes, vulnerability to pollution, and the general hydrogeological functioning of these kind of aquifers. To gain deeper insight into the soil-water-rock hydrogeochemical processes occurring throughout the vertically hierarchized compartments of the aquifer and to evaluate the applicability of different soil natural parameters as groundwater flow tracers, the present work analyzes the spatial and temporal evolution of total organic carbon -TOC-, intrinsic fluorescence related to organic matter, nitrates, δ13CTDIC, and the values of stable isotopes of δ2H and δ18O from water molecules and at different sampling points in a geologically complex karst aquifer in south Spain (Jarastepar carbonate massif). Over two years, rain and soil water (30 and 60 cm deep) samples were collected simultaneously at an experimental plot along with groundwater from the top of the saturated zone and a base-level spring. Results show that the variation in the concentration of natural soil tracers and the signal of water stable isotopes (δ2H and δ18O) smooth throughout the different compartments of the aquifer, with rapid variations in the unsaturated zone after recharge events and delayed effects in the saturated zone.Funding for open access charge: Universidad de Málaga / CBUA. This research was supported by the project PID2019-111759RB-I00 funded by the Agencia Estatal de Investigación (AEI/https://doi.org/10.13039/501100011033) of the Spanish Government