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141.
Intrinsic vulnerability assessment of Saturnia thermal aquifer by means of three parametric methods: SINTACS,GODS and COP 总被引:2,自引:1,他引:1
Enrico Guastaldi Luca Graziano Giovanni Liali Fabio Nunzio Antonio Brogna Alessio Barbagli 《Environmental Earth Sciences》2014,72(8):2861-2878
Three different parametric methods for the evaluation of intrinsic vulnerability to pollution have been applied in a hydrothermal carbonate aquifer located in central-northern Italy and the results obtained were compared with each other. The study area, large, approximately 152 km2, lies in an area of the northern Apennines. The investigated aquifer feeds the hot thermal springs of Saturnia. The vulnerability assessment methods used are: SINTACS, GODS and COP. The vulnerability maps obtained were first individually examined, and then they were compared with each other by means of spatial analysis. These maps show similar results for the estimation of the vulnerability just in some areas. SINTACS yields areas potentially vulnerable to pollution along the Albegna River and its major tributaries in the northern part of the study area. The GODS index map reflects the great importance that this method gives to the lithological characteristics of the unsaturated zone in the subdivision of areas with different vulnerability. GODS and COP methods agree in classifying low vulnerability in the most part of central-southern study area, where the aquifer is confined by the Pliocene clay deposits. Based on the conceptual model of groundwater flow developed for the aquifer under investigation, COP seems the most appropriate method among those applied in this work, in particular with regard to the assessment of the vulnerability of the recharge area of thermal groundwater. Located in the northern part of the study area, where karst carbonate formations of the Tuscan Nappe outcrop, this recharge area is classified by the COP method as highly vulnerable to pollution. 相似文献
142.
Degli Abbati Stefania Morandi Paolo Cattari Serena Spacone Enrico 《Bulletin of Earthquake Engineering》2022,20(4):2187-2217
Bulletin of Earthquake Engineering - This paper presents the comparison of the results of modal and nonlinear analyses carried out on a 2-story masonry building with rigid diaphragms, inspired by... 相似文献
143.
Acta Geotechnica - Slope stability in reservoirs depends on time-dependent triggering factors such as fluctuations of the groundwater level and precipitation. This paper assesses the stability of... 相似文献
144.
An Advanced Systematic Literature Review on Spatiotemporal Analyses of Twitter Data 总被引:4,自引:1,他引:3
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The objective of this article is to conduct a systematic literature review that provides an overview of the current state of research concerning methods and application for spatiotemporal analyses of the social network Twitter. Reviewed papers and their application domains have shown that the study of geographical processes by using spatiotemporal information from location‐based social networks represent a promising and still underexplored field for GIScience researchers. 相似文献
145.
146.
Ferdinando Patat Stefano Benetti Enrico Cappellaro Massimo Turatto 《Monthly notices of the Royal Astronomical Society》2006,369(4):1949-1960
In this paper, we present and discuss the effects of scattered light echoes (LEs) on the luminosity and spectral appearance of Type Ia supernovae (SNe). After introducing the basic concept of LE spectral synthesis by means of LE models and real observations, we investigate the deviations from pure SN spectra, light and colour curves, the signatures that witness the presence of an LE and the possible inferences on the extinction law. The effects on the photometric parameters and spectral features are also discussed. In particular, for the case of circumstellar dust, LEs are found to introduce an apparent relation between the post-maximum decline rate and the absolute luminosity, which is most likely going to affect the well-known Pskowski–Phillips relation. 相似文献
147.
The tectonics of the central Aeolian Islands, which are located within the Tyrrhenian backarc basin, has been investigated through a marine seismic reflection survey. We find that compressional structures dominate around the islands, whereas extensional faults occur only to the north of Salina and Filicudi, towards the Marsili basin. This pattern of deformation, although different from previously reported, is in agreement with the strain field and stress regime obtained from GPS measurements and seismological data. Age constraints suggest that contractional deformation was active since middle Pleistocene, being coeval with the building of the volcanic edifices of the Aeolian Islands, and is superimposed on pre‐existing extensional deformation. Compressional and extensional regimes, therefore, can coexist within a backarc setting. Seismic profiles show that the Tindari‐Letojanni fault, considered as a major tectonic element, does not extend to the north towards the island of Vulcano as a throughgoing fault; rather, deformation is accommodated in a broader belt displaying greater structural complexity. 相似文献
148.
Enrico Ramirez-Ruiz Andrea Merloni 《Monthly notices of the Royal Astronomical Society》2001,320(3):L25-L29
Although more than 2000 astronomical gamma-ray bursts (GRBs) have been detected, the precise progenitor responsible for these events is unknown. The temporal phenomenology observed in GRBs can significantly constrain the different models. Here we analyse the time histories of a sample of bright, long GRBs, searching for the ones exhibiting relatively long (more than 5 per cent of the total burst duration) 'quiescent times', defined as the intervals between adjacent episodes of emission during which the gamma-ray count rate drops to the background level. We find a quantitative relation between the duration of an emission episode and the quiescent time elapsed since the previous episode. We suggest here that the mechanism responsible for the extraction and the dissipation of energy has to take place in a metastable configuration, such that the longer the accumulation period, the higher the stored energy available for the next emission episode. 相似文献
149.
Valentina Ciriello Vittorio Di Federico Monica Riva Francesco Cadini Jacopo De Sanctis Enrico Zio Alberto Guadagnini 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(4):945-954
We perform global sensitivity analysis (GSA) through polynomial chaos expansion (PCE) on a contaminant transport model for the assessment of radionuclide concentration at a given control location in a heterogeneous aquifer, following a release from a near surface repository of radioactive waste. The aquifer hydraulic conductivity is modeled as a stationary stochastic process in space. We examine the uncertainty in the first two (ensemble) moments of the peak concentration, as a consequence of incomplete knowledge of (a) the parameters characterizing the variogram of hydraulic conductivity, (b) the partition coefficient associated with the migrating radionuclide, and (c) dispersivity parameters at the scale of interest. These quantities are treated as random variables and a variance-based GSA is performed in a numerical Monte Carlo framework. This entails solving groundwater flow and transport processes within an ensemble of hydraulic conductivity realizations generated upon sampling the space of the considered random variables. The Sobol indices are adopted as sensitivity measures to provide an estimate of the role of uncertain parameters on the (ensemble) target moments. Calculation of the indices is performed by employing PCE as a surrogate model of the migration process to reduce the computational burden. We show that the proposed methodology (a) allows identifying the influence of uncertain parameters on key statistical moments of the peak concentration (b) enables extending the number of Monte Carlo iterations to attain convergence of the (ensemble) target moments, and (c) leads to considerable saving of computational time while keeping acceptable accuracy. 相似文献
150.
Giuseppe Altavilla Maria Teresa Botticella Enrico Cappellaro Massimo Turatto 《Astrophysics and Space Science》2012,341(1):163-178
Despite decades of dedicated efforts there are still basic questions to answer with regard to Supernova progenitor systems and explosion mechanisms. In particular, in the last years a number of exceptionally bright objects and extremely faint events have demonstrated an unexpected large Supernova variety. 相似文献