Soil contamination from urban and industrial activity: example of the mining district of Linares (southern Spain)   总被引：1，自引：0，他引：1  

J. Martínez  J. F. Llamas  E. de Miguel  J. Rey  M. C. Hidalgo 《Environmental Geology》2008,54(4):669-677

The Linares region (southern Spain) has been subjected to two important sources of pollution: the intensive mining works and the urban-industrial activity. To obtain a geochemical characterisation of the soil, 31 trace elements were analysed and 669 soil samples were collected. By means of clustering analysis, we identified groups of elements and grid squares in which relations could be established concerning soil lithology, urban and industrial activities and the degree of pollution impact; in addition, we were able to characterise the geochemical background of the study area. The multivariate study led us to identify four factors. Particularly important was factor 2, which represented the elements associated with mineral paragenesis (Cu, Pb, As, Co, Mn, Zn, Sn, Ba). This factor also contains elements related with an urban-industrial activity, such as Pb, Cu, Zn, As and Ba. Furthermore, we identified factor 4, associating Ni, V and Cr, and which is related to the use of fuels.  相似文献   

Seasonal and inter-annual variation of mesozooplankton in the coastal upwelling zone off central-southern Chile   总被引：1，自引：0，他引：1  

Ruben Escribano  Pamela Hidalgo  Humberto González  Ricardo Giesecke  Ramiro Riquelme-Bugueño  Karen Manríquez 《Progress in Oceanography》2007,75(3):470-485

Zooplankton sampling at Station 18 off Concepción (36°30′S and 73°07′W), on an average frequency of 30 days (August 2002 to December 2005), allowed the assessment of seasonal and inter-annual variation in zooplankton biomass, its C and N content, and the community structure in relation to upwelling variability. Copepods contributed 79% of the total zooplankton community and were mostly represented by Paracalanus parvus, Oithona similis, Oithona nana, Calanus chilensis, and Rhincalanus nasutus. Other copepod species, euphausiids (mainly Euphausia mucronata), gelatinous zooplankton, and crustacean larvae comprised the rest of the community. Changes in the depth of the upper boundary of the oxygen minimum zone indicated the strongly seasonal upwelling pattern. The bulk of zooplankton biomass and total copepod abundance were both strongly and positively associated with a shallow (<20 m) oxygen minimum zone; these values increased in spring/summer, when upwelling prevailed. Gelatinous zooplankton showed positive abundance anomalies in the spring and winter, whereas euphausiids had no seasonal pattern and a positive anomaly in the fall. The C content and the C/N ratio of zooplankton biomass significantly increased during the spring when chlorophyll-a was high (>5 mg m⁻³). No major changes in zooplankton biomass and species were found from one year to the next. We concluded that upwelling is the key process modulating variability in zooplankton biomass and its community structure in this zone. The spring/summer increase in zooplankton may be largely the result of the aggregation of dominant copepods within the upwelling region; these may reproduce throughout the year, increasing their C content and C/N ratios given high diatom concentrations.  相似文献   

Short-term cadmium effects on gill tissue metabolism     

L. Tort  P. Torres  J. Hidalgo 《Marine pollution bulletin》1984,15(12):448-450

ATP, lactate and respiratory rate in dogfish gill tissue were analysed after 50 ppm cadmium treatment. ATP levels decrease significantly after two days treatment but no differences with respect to the control values were detected after three, four or six days. Lactate increased after one day treatment and values were maintained after two and three days, recovering the control values from the fourth day. Oxygen consumption rate agree with the former patterns. After two days treatment a low rate (49% of controls) was recorded, while the respiratory rate after six days recovered in the 82% of the controls.  相似文献   

Factors affecting arsenic concentration in groundwaters from Northwestern Chaco-Pampean Plain,Argentina     

María Gabriela García  Ondra Sracek  Diego Sebastián Fernández  Margarita del Valle Hidalgo 《Environmental Geology》2007,52(7):1261-1275

The concentration of arsenic measured in groundwater from three aquifers in the study area located in the Eastern Tucuman province, Argentina, mostly depends on the lithology, but the spatial and temporal variations of concentrations seem to be also controlled by pH changes, climatic factors, and human perturbations. The highest concentrations of As (more than 1,000 μg L⁻¹) were found in the shallow aquifer, made of As-rich loess, while the lowest concentrations were measured in the deep confined aquifer, consisting of alternating layers of alluvial sands/gravels and clays. Intermediate values were measured in the semiconfined aquifer made of the fluvial sediments deposited in the Salí River valley, that alternate in the upper part of the sedimentary sequence with layers of loess. Because most of As in the loess is considered to be adsorbed onto Fe-oxyhydroxide coatings, the increase of pH in the flow direction (west-east) leads to increasing arsenic concentrations towards the eastern border of the study area. The decomposition of organic wastes poured into the Salí River or associated with local and diffuse sources of contamination in the eastern part of the study area depletes dissolved oxygen, which leads to the reductive dissolution of Fe and Mn oxyhydroxides, and to the subsequent release of the adsorbed and co-precipitated As. This process mainly affects shallow groundwater and the upper part of the semiconfined aquifer. Geochemical and hydrological data also suggest that rising water table levels at the end of the wet season may also lead to reductive dissolution of As-rich Fe oxyhydroxides in the shallow aquifer.  相似文献   

Chemical behavior of the Salí River, Province of Tucumán, Argentina     

M. Galindo  M. Vece  M. Perondi  M. Monserrat Aráoz  G. García  M. del V. Hidalgo  M. Apella  M. Blesa 《Environmental Geology》2001,40(7):847-852

Major ionic composition and other chemical parameters were determined at five sampling stations on the Salí River (Province of Tucumán, Argentina). The heavy human usage of the river causes increased levels of dissolved ions, from the dissolution of halite and gypsum, and from the weathering of basic sediments. Correlations demonstrate that sodium chloride and sulphate, and calcium carbonate are the main contributors to dissolved ions in the river. In the polluted region, south of the Celestino Gelsi dam, the main source of calcium and sulphate is the dissolution of gypsum. Large amounts of halite are also dissolved. Weathering of biotite, K-feldspar and albite are suggested by the data. Conductivity, dissolved oxygen and organic matter all indicate severe contamination by organic matter (mainly from sugar-cane processing) in the lower course. The data also demonstrate a substantial improvement in water quality before the discharge of the river at the Río Hondo dam. Data from the Colorado (a tributary of the Salí River) and Medina rivers are also analyzed and compared.  相似文献   

Geochemistry of groundwater in the alluvial plain of Tucumán province, Argentina   总被引：3，自引：0，他引：3  

Gabriela M. García  Margarita del V. Hidalgo  Miguel A. Blesa 《Hydrogeology Journal》2001,9(6):597-610

The Salí River hydrogeological basin is one of the most productive artesian basins in Argentina. It is located in the southeastern part of the province of Tucumán, northwestern Argentina, and its groundwater resources are developed for water supply and irrigation. The chemical composition of the water is strongly influenced by the interaction with the basinal sediments and by hydrologic characteristics such as the flow pattern and time of residence. Three hydrochemical zones are defined in the study area and the processes that control the chemical composition of the water are manifestly different in each zone. The dissolution of halite, sodium sulphate, and gypsum explains part of the contained Na⁺, K⁺, Cl^–, SO₄ ^2–, and Ca²⁺, but other processes, such as cation exchange, calcite precipitation, weathering of aluminosilicates, and gas exchange with the atmosphere, also contribute to the water composition. The assessment of contamination indicators, such as pH, dissolved organic matter, dissolved oxygen, phosphate, and nitrate, indicates that the groundwater is suitable for human consumption. However, biological contamination has been detected in samples from some wells, especially those near the Salí River. Electronic Publication  相似文献   

Predation on the rocky shores of Patagonia,Argentina     

Fernando J. Hidalgo  Brian R. Silliman  María Cielo Bazterrica  Mark D. Bertness 《Estuaries and Coasts》2007,30(5):886-894

Rocky intertidal communities of Argentinean Patagonia are exposed to harsh physical conditions caused by dry, strong southern trade winds (mean speed 45 km h^-1, gusts up to 140 km h^-1) that result in intense desiccation of intertidal organisms. Predator distributions in these communities were evaluated from April 2003 to December 2004 at two exposed headlands and six protected bays in Cabo dos Bahias (44°50′S, 65°40′W). Crabs and sea stars dominated the predator assemblage, with occasional scavenger snails and fish also present. During low tide, predators were never found in the open but were always associated with shelter (primarily within mussel beds and coralline algae), suggesting a strong predator dependency on foundation species to buffer them from physical stress. Few predators (mostly crabs) emerged from shelter at high tide. Unlike the larger predators found on Chilean rocky shores, invertebrate predators in this system are diminutive, generally < 2 cm. The lone exception was the newly discovered invasive green crab,Carcinus mamas. Feeding trials, gut content analyses, and visual surveys indicated that native predators feed primarily on small, soft-bodied prey.C. mamas fed on slow-moving and sessile animals, including the super abundant musselPerumytilus purpuratus, with much greater voracity than native predators. Because native intertidal organisms are dependent on mussel beds and coralline algae for shelter from desiccation, successful invasion ofC. mamas may lead to a significant decrease in native diversity by consuming foundation species. This study represents a preliminary survey of predator distributions and feeding habits on the rocky shores of Argentinean Patagonia and provides important baseline data to evaluate trophic linkages and predatory effects on Patagonian rocky shores.  相似文献   

Inverse problem in hydrogeology   总被引：14，自引：6，他引：8  

Jesús Carrera  Andrés Alcolea  Agustín Medina  Juan Hidalgo  Luit J. Slooten 《Hydrogeology Journal》2005,13(1):206-222

The state of the groundwater inverse problem is synthesized. Emphasis is placed on aquifer characterization, where modelers have to deal with conceptual model uncertainty (notably spatial and temporal variability), scale dependence, many types of unknown parameters (transmissivity, recharge, boundary conditions, etc.), nonlinearity, and often low sensitivity of state variables (typically heads and concentrations) to aquifer properties. Because of these difficulties, calibration cannot be separated from the modeling process, as it is sometimes done in other fields. Instead, it should be viewed as one step in the process of understanding aquifer behavior. In fact, it is shown that actual parameter estimation methods do not differ from each other in the essence, though they may differ in the computational details. It is argued that there is ample room for improvement in groundwater inversion: development of user-friendly codes, accommodation of variability through geostatistics, incorporation of geological information and different types of data (temperature, occurrence and concentration of isotopes, age, etc.), proper accounting of uncertainty, etc. Despite this, even with existing codes, automatic calibration facilitates enormously the task of modeling. Therefore, it is contended that its use should become standard practice.

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Resumen Se sintetiza el estado del problema inverso en aguas subterráneas. El énfasis se ubica en la caracterización de acuíferos, donde los modeladores tienen que enfrentar la incertidumbre del modelo conceptual (principalmente variabilidad temporal y espacial), dependencia de escala, muchos tipos de parámetros desconocidos (transmisividad, recarga, condiciones limitantes, etc), no linealidad, y frecuentemente baja sensibilidad de variables de estado (típicamente presiones y concentraciones) a las propiedades del acuífero. Debido a estas dificultades, no puede separarse la calibración de los procesos de modelado, como frecuentemente se hace en otros campos. En su lugar, debe de visualizarse como un paso en el proceso de entendimiento del comportamiento del acuífero. En realidad, se muestra que los métodos reales de estimación de parámetros no difieren uno del otro en lo esencial, aunque sí pueden diferir en los detalles computacionales. Se discute que existe amplio espacio para la mejora del problema inverso en aguas subterráneas: desarrollo de códigos amigables al usuario, acomodamiento de variabilidad a través de geoestadística, incorporación de información geológica y diferentes tipos de datos (temperatura, presencia y concentración de isótopos, edad, etc), explicación apropiada de incertidumbre, etc. A pesar de esto, aún con los códigos existentes, la calibración automática facilita enormemente la tarea de modelado. Por lo tanto, se sostiene que su uso debería de convertirse en práctica standard.

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Résumé Létat du problème inverse des eaux souterraines est synthétisé. Laccent est placé sur la caractérisation de laquifère, où les modélisateurs doivent jouer avec lincertitude des modèles conceptuels (notamment la variabilité spatiale et temporelle), les facteurs déchelle, plusieurs inconnues sur différents paramètres (transmissivité, recharge, conditions aux limites, etc.), la non linéarité, et souvent la sensibilité de plusieurs variables détat (charges hydrauliques, concentrations) des propriétés de laquifère. A cause de ces difficultés, le calibrage ne peut être séparé du processus de modélisation, comme cest le cas dans dautres cas de figure. Par ailleurs, il peut être vu comme une des étapes dans le processus de détermination du comportement de laquifère. Il est montré que les méthodes dévaluation des paramètres actuels ne diffèrent pas si ce nest dans les détails des calculs informatiques. Il est montré quil existe une large panoplie de techniques d ‹inversion : codes de calcul utilisables par tout-un-chacun, accommodation de la variabilité via la géostatistique, incorporation dinformations géologiques et de différents types de données (température, occurrence, concentration en isotopes, âge, etc.), détermination de lincertitude. Vu ces développements, la calibration automatique facilite énormément la modélisation. Par ailleurs, il est souhaitable que son utilisation devienne une pratique standardisée.

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Urban-breeze circulation during the CAPITOUL experiment: observational data analysis approach     

J. Hidalgo  G. Pigeon  V. Masson 《Meteorology and Atmospheric Physics》2008,102(3-4):223-241

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Relationship between volcanic ash fallouts and seismic tremor: quantitative assessment of the 2015 eruptive period at Cotopaxi volcano,Ecuador     

Benjamin Bernard  Jean Battaglia  Antonio Proaño  Silvana Hidalgo  Francisco Vásconez  Stephen Hernandez  Mario Ruiz 《Bulletin of Volcanology》2016,78(11):80

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