192 research outputs found
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
Complementary use of hydrodynamic and hydrochemical tools to infer groundwater-surface water interactions in rivers located in alpine karst environments. The Segura and Zumeta rivers (Jaén province, SE Spain).
Knowledge of surface water / groundwater interactions in high mountain karst regions is crucial for enhancing the protection and management of water resources. This is particularly relevant when dealing with mountainous areas located in the Mediterranean region, such as Sierra de Segura (SE Spain), one of the largest carbonate outcrops (3000 km2) in the Iberian Peninsula. This region acts as headwater of rivers flowing eastward (Mediterranean Sea) and westward (Atlantic Ocean) over Cretaceous-Tertiary limestones and dolostones. However, information on the surface water-groundwater interactions in rivers and streams found in the area is still limited, as well as their role in the functioning of the carbonate aquifers. This research shows the preliminary results obtained from hydrological (flow-rate) and hydrochemical records (electrical conductivity -EC-, temperature, major ions, total organic carbon -TOC-, dissolved gases -O2 and 222Rn-) measured along two of the main rivers in the area (Segura and Zumeta). 218 discharge and physico-chemical parameter measurements were carried out during theUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Perspectivas ante el inicio de las negociaciones de adhesión de Turquía a la Unión Europea
Este documento trata de las perspectivas económicas y políticas de dicha ampliación para ambas partes, de las perspectivas que se presentan en política internacional y en el propio funcionamiento de las instituciones europeas ante la perspectiva de la incorporación de Turquía a la Unión Europea. En primer lugar encontrará el lector un repaso al proceso de transposición de normas comunitarias llevado a cabo por Turquía, seguido de un comentario sobre las peculiaridades del presente proceso de negociación. Un tercer apartado analiza la evolución reciente y el presente de la economía turca. Repasaremos también las líneas generales de la demografía turca. El quinto apartado está dedicado a analizar la situación presente y perspectivas futuras en el campo de las relaciones internacionales. Por último, analizaremos los aspectos culturales, sociales y de política interna y las posibles consecuencias para ambas partes de un fracaso del proceso negociador
Advancing in the estimation of effective recharge and its propagation in karst aquifers by combining soil moisture observations and the natural responses of springs. An example from Southern Spain.
Improving our comprehension of infiltration processes in karst systems is crucial for a better adaptation to the global change regarding water resources availability and management. In this work, the effective recharge under different meteorological conditions and its transfer along the vertically distributed compartments of a geologically complex karst aquifer in southern Spain have been evaluated. Continuous records of soil moisture and temperature values (at 5 and 10 cm depth and the soil-rock transition -average depth of 28 cm-) have been combined with hourly hydrodynamic and hydrothermal responses recorded at two springs with a marked influence of the unsaturated zone (UZ) and the saturated zone (SZ), respectively.
Most rainfalls generate soil moisture signal in the shallowest probes. However, a mean increase of soil water content of 10.5% in summer (from background values of 2.5%) and 6.1% in autumn-winter (from 9.6%) at the soil-rock interface were needed to produce hydrodynamic responses in the system: first in the spring related to the UZ, with a time delay of 4-9 hours after moisture peaks, and then (14-18 hours) in the spring draining the SZ, but only during autumn-winter recharge events. In addition, recharge caused decreases (up to 0.9°C) in the temperature of the water drained by the first spring, while lagged rises (up to 0.6°C) occurred in the second outlet.
Transmission of the input signal would be favoured by stronger karstification, but the presence of inter-bedded detrital formations in the lithological sequence of the aquifer (partially confined in the SE border) filter and buffer groundwater flows before being drained by the spring related to the SZ. These findings will help to assess thresholds for effective infiltration and to predict groundwater recharge in karst aquifers under different climate change scenarios.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Fraccionamiento de contaminantes orgánicos persistentes en aire urbano de Madrid: fase gas y fase particulada.
En el presente trabajo se evaluó la presencia de algunos Contaminantes Orgánicos Persistentes (COP) en muestras de aire de la ciudad de Madrid (España), discriminando entre la fase gas (FG) y la materia particulada en suspensión (MPS). Para ello se utilizaron captadores activos de alto volumen (CAV) equipados con espumas de poliuretano y filtros de microfibra de vidrio. Los policlorobifenilos resultaron los contaminantes mayoritarios (104.6 ± 86.6 pg/Nm3, media ± desviación estándar), seguidos de polibromodifenil éteres (20.4 ± 11.6 pg/Nm3), declorane plus (0.8 ± 0.5 pg/Nm3) y finalmente policlorodibenzo-p-dioxinas y policlorodibenzofuranos (0.3 ± 0.1 pg/Nm3). Los resultados, en concordancia con los obtenidos en otras ciudades, no sólo confirman la presencia de COP en el aire de Madrid, sino que evidencian diferencias importantes en cuanto al fraccionamiento (presencia mayoritaria en la fase gas o en la fase particulada) entre los distintos analitos y congéneres evaluados
Validity of applying Theis and Cooper-Jacob analytical solutions in pumping tests carried out in coastal aquifers
Two pumping tests were performed in the unconfined detrital Motril-Salobreña aquifer in a 250 metre-deep artesian well 300 m from the coastline containing both freshwater and saltwater. The two observation wells where the drawdowns are measured record the influence of tidal fluctuations and a high vertical heterogeneity in the aquifer. The Theis and Cooper-Jacob approaches give average T and S values of 1,460 m2/d and 0.027, respectively. Numerical modelling in a synthetic model was applied to analyse the sensitivity of the Theis and Cooper-Jacob approaches to the usual boundary conditions in coastal aquifers. The T and S values calculated from the numerical modelling drawdowns indicate that the regional flow, variable pumping flows, and tidal effect produce an error of under 10% in results obtained with classic methods. Fluids of different density (freshwater and saltwater) cause an error of 20% in estimating T and of over 100% in calculating S. The factor most affecting T and S results in the pumping test interpretation is vertical heterogeneity in sediments, which can produce errors of over 100% in both parametersEn el acuífero costero Motril-Salobreña se realizaron dos ensayos de bombeo en un sondeo surgente de 250 m de profundidad localizado a 300 m del borde costero en el que se detectó la presencia de agua dulce y agua salada y una fuerte heterogeneidad vertical. En los dos piezómetros donde se miden los descensos, se registra la influencia de las oscilaciones mareales. La aplicación de las soluciones analíticas de Theis y Cooper-Jacob da valores medios de T y S de 1.460 m2/d y 0,027, respectivamente. Para analizar la sensibilidad de las aproximaciones de Theis y Cooper-Jacob ante condiciones de contorno que suelen aparecer en acuíferos costeros se ha aplicado un modelo matemático sintético. Los valores de T y S calculados a partir de los descensos resultantes del modelo indican que la existencia de un flujo regional, un caudal de bombeo variable y el efecto de las mareas producirá un error inferior al 10% en los resultados obtenidos con los métodos clásicos. La presencia de fluidos de diferente densidad provocará un error del 20% para T y mayor del 100% para S. El factor que más afecta a los resultados de T y S en la interpretación de ensayos de bombeo es la heterogeneidad vertical de los sedimentos que pueden dar errores superiores al 100% para ambos parámetro
222Rn as a natural tracer to investigate recharge and groundwater flow dynamics at three Mediterranean karst systems in Southern Spain.
Comprehensive knowledge of groundwater origin and movement into karst aquifers is crucial to establish the adequate management practices. This is of special interest in areas strongly affected by the impact of climate change, such as the Mediterranean region. This work aims to better understand recharge processes determining groundwater flow in 3 mountainous carbonate aquifers in Southern Spain. To achieve this purpose, spring discharge and electrical conductivity data as well as 222Rn activity were measured and interpreted in karst groundwater.
Karst groundwater discharge at the investigated springs varies between 3 and 1400 L/s, while electrical conductivity (EC) values range between 227 and 1929 µS/cm. 222Rn activity data are found between 31-3630 Bq/m3. The temporal evolution of EC, water temperature and 222Rn showed relatively constant values during dry periods in all examined karst springs but abrupt decreases after intense recharge events. A detailed –daily- control during high waters in the Sierra de Ubrique revealed slight increases in 222Rn activity at the beginning of the rising limb of spring discharge. However, circulation of recently infiltrated rainwater through karst conduits (in turbulent flow regimes) and the mixing with old waters provokes a marked dropping in the measured parameters at karst springs.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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
Radial and tangential migration of telencephalic somatostatin neurons originated from the mouse diagonal area
The telencephalic subpallium is the source of various GABAergic interneuron cohorts that invade the pallium via tangential migration. Based on genoarchitectonic studies, the subpallium has been subdivided into four major domains: striatum, pallidum, diagonal area and preoptic area (Puelles et al. 2013; Allen Developing Mouse Brain Atlas), and a larger set of molecularly distinct progenitor areas (Flames et al. 2007). Fate mapping, genetic lineage-tracing studies, and other approaches have suggested that each subpallial subdivision produces specific sorts of inhibitory interneurons, distinguished by differential peptidic content, which are distributed tangentially to pallial and subpallial target territories (e.g., olfactory bulb, isocortex, hippocampus, pallial and subpallial amygdala, striatum, pallidum, septum). In this report, we map descriptively the early differentiation and apparent migratory dispersion of mouse subpallial somatostatin-expressing (Sst) cells from E10.5 onward, comparing their topography with the expression patterns of the genes Dlx5, Gbx2, Lhx7-8, Nkx2.1, Nkx5.1 (Hmx3), and Shh, which variously label parts of the subpallium. Whereas some experimental results suggest that Sst cells are pallidal, our data reveal that many, if not most, telencephalic Sst cells derive from de diagonal area (Dg). Sst-positive cells initially only present at the embryonic Dg selectively populate radially the medial part of the bed nucleus striae terminalis (from paraseptal to amygdaloid regions) and part of the central amygdala; they also invade tangentially the striatum, while eschewing the globus pallidum and the preoptic area, and integrate within most cortical and nuclear pallial areas between E10.5 and E16.5.This work was funded by the Spanish Ministry of Science and Innovation grant BFU2008-04156, and SENECA Foundation contract 0458/GERM/06-10891 to L.P.; and the Local Government of Castilla-La Mancha grant PII1I09-0065-8194 to C.D. Infrastructure support provided by the University of Murcia and Castilla-La Mancha is also acknowledged
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