Monitoring of mercury and other metals mobility by sequential fractionation in soils nearby an abandoned chlor-alkali plant in Managua (Nicaragua)     

Rodolfo Fernández-Martínez  Belén Gómez-Mancebo  Emilio J. Peña  Pilar Galán  Akito Matsuyama  Fernando García  Isabel Rucandio 《Environmental Earth Sciences》2016,75(6):538

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Study of the growth of southern black and white monkfish stocks   总被引：1，自引：0，他引：1  

Duarte  Rafael; Azevedo  Manuela; Pereda  Pilar 《ICES Journal of Marine Science》1997,54(5):866-874

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Investigating young water fractions in a small Mediterranean mountain catchment: Both precipitation forcing and sampling frequency matter     

Francesc Gallart  María Valiente  Pilar Llorens  Carles Cayuela  Matthias Sprenger  Jérôme Latron 《水文研究》2020,34(17):3618-3634

The proportion of water younger than 2–3 months (young water fraction, F_yw) has become increasingly investigated in catchment hydrology. F_yw is typically estimated by comparing seasonal tracer cycles in precipitation and streamflow, through water sampling. However, some open research questions remain, such as: (i) whether part of the summer precipitation should be discarded because the high evapotranspiration demand, (ii) how well F_yw serves as a metric to compare catchments, and (iii) how sampling frequency affects F_yw estimates. To address these questions, we investigated F_yw in soil-, ground- and stream waters for the small Mediterranean Can Vila catchment. Rainfall was sampled at 5-mm intervals. Mobile soil water and groundwater were sampled fortnightly. Stream water was sampled depending on flow at variable time intervals (30 min to 1 week). Over 58 months, this sampling provided 1,529 δ¹⁸O determinations. Isotopic analyses results led us to include summer precipitation in the input signal. We found the highest F_yw in mobile soil waters (34%), while this was almost zero for groundwater except during wet periods. For stream waters, F_yw depended on the discharge variations, so that the flow-weighted young water fraction () was 22.6%, whereas the time-weighted F_yw was just 6.2%. Both and its discharge sensitivity (S_d) varied when different 12-month sampling periods were investigated. The young water fraction that would be obtained from a virtual thorough sampling () was estimated from the S_d and the observed stream flow. This showed an underestimation of by 25% for the frequent dynamic sampling and 66% for weekly sampling, due to missing high flows. Our results confirm that F_yw and its discharge sensitivity are metrics very sensitive to meteorological forcing during the analysed period. Thus, comparisons between catchments need long-term mean annual values and their variability. Our findings also support the dependence of F_yw estimates on the sampling rate and show the advantages of flow-weighted analysis. Finally, catchment water turnover investigations should be accompanied by the analysis of flow duration curves.  相似文献   

Increasing the detail of European land use/cover data by combining heterogeneous data sets     

Konštantín Rosina  Filipe Batista e Silva  Pilar Vizcaino  Mario Marín Herrera  Sérgio Freire  Marcello Schiavina 《International Journal of Digital Earth》2020,13(5):602-626

ABSTRACT

Data on land use and land cover (LULC) are a vital input for policy-relevant research, such as modelling of the human population, socioeconomic activities, transportation, environment, and their interactions. In Europe, CORINE Land Cover has been the only data set covering the entire continent consistently, but with rather limited spatial detail. Other data sets have provided much better detail, but either have covered only a fraction of Europe (e.g. Urban Atlas) or have been thematically restricted (e.g. Copernicus High Resolution Layers). In this study, we processed and combined diverse LULC data to create a harmonised, ready-to-use map covering 41 countries. By doing so, we increased the spatial detail (from 25 to one hectare) and the thematic detail (by seven additional LULC classes) compared to the CORINE Land Cover. Importantly, we decomposed the class ‘Industrial and commercial units’ into ‘Production facilities’, ‘Commercial/service facilities’ and ‘Public facilities’ using machine learning to exploit a large database of points of interest. The overall accuracy of this thematic breakdown was 74%, despite the confusion between the production and commercial land uses, often attributable to noisy training data or mixed land uses. Lessons learnt from this exercise are discussed, and further research direction is proposed.  相似文献   

Geoelectric dimensionality in complex geological areas: application to the Spanish Betic Chain   总被引：1，自引：0，他引：1  

Anna Martí  Pilar Queralt  Eduard Roca 《Geophysical Journal International》2004,157(3):961-974

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Persistent organic pollutants in remote freshwater ecosystems   总被引：3，自引：0，他引：3  

Pilar Fernández  Guillem Carrera  Joan O. Grimalt 《Aquatic Sciences - Research Across Boundaries》2005,67(3):263-273

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The significance of European high mountain lakes in critical load distributions at the EMEP grid scale     

Chris J. Curtis  Max Posch  Pilar Casals-Carrasco  Jordi Catalan  Mike Hughes  Martin Kernan  Marc Ventura 《Aquatic Sciences - Research Across Boundaries》2005,67(3):252-262

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Effects of galvanic distortion on magnetotelluric data over a three-dimensional regional structure   总被引：2，自引：0，他引：2  

Juanjo Ledo  Pilar Queralt  & Jaume Pous 《Geophysical Journal International》1998,132(2):295-301

Although the galvanic distortion due to local, near-surface inhomogeneities is frequency-independent, its effect on the magnetotelluric data becomes, in a 3-D structure, frequency-dependent. Therefore, both the apparent resistivity and the phase responses are disturbed, and a correction should be carried out prior to the 3-D interpretation in order to retrieve the 3-D regional impedance tensor. In many cases, the structure is 2-D for depths corresponding to a first range of periods and 3-D for longer periods (called 2-D/3-D). For these cases, a simple method which allows us to retrieve the 3-D regional impedance tensor (except the static shift) is presented. The method proposed uses the Groom & Bailey decomposition of the distortion matrix for the short periods. Three examples are presented: two using synthetic data and one employing real data. These examples show the effect of the galvanic distortion over a regional 2-D/3-D model and the retrieval of the regional transfer functions from the distorted ones.  相似文献   

Lateral and topographic effects in geoelectric soundings     

Jaume Pous  Pilar Queralt  René Chavez 《Journal of Applied Geophysics》1996,35(4):237-248

Several two-dimensional structures are modelled for vertical electrical soundings in arrays parallel and perpendicular to the strike of the structure. The models are a horst and a graben within a three-layer medium, a cliff over two layers, and heterogeneities around the electrodes. Apparent resistivity curves are shown for different model parameters and different distances to the two-dimensional structures. Some of the features on the shape of these curves are inflections that may be misinterpreted as fictitious layers, of slopes greater than 45°; some features are simply anomalous peaks. One-dimensional interpretation of a two-dimensional graben model has been performed, in order to show typical errors when 2D structures are interpreted as one-dimensional. A real case corresponding to a landfill near Barcelona and showing strong lateral and topographic effects is presented. This represents combined effects of the above theoretical 2D models.  相似文献   

Analyse Multielementaire de Six Echantillons de Reference "d' United States Geological Survey" GXR-1 a 6 par Spectrometrie d'Emission Atomique a Plasma Conductif     

M. Pilar RODRIGUEZ 《Geostandards and Geoanalytical Research》1986,10(2):155-158

Une méthode spectrométrique d'émission atomique à plasma conductif a été appliquée pour l'analyse multiélementaire des échantillons USGS GXR-1 à 6. Cette méthode permet de déterminer simultanément 22 éléments: Ag, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Nb, Ni, P, Pb, Sb, Sn, V, W, Y et Zn, au niveau de traces (ppm) et le Fe en (%). Les résultats obtenus démontrent une bonne concordance avec les valeurs préalablement publiées.  相似文献