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Multidisciplinary investigation of the natural and anthropogenic ground movements in the Po Plain (Northern Italy) using geological and satellite data
Get PDFL'abstract è presente nell'allegato / the abstract is in the attachmen
Cluster analysis of InSAR data for the investigation of groundwater production effects
Get PDFInSAR time series analysis is a powerful tool used in remote sensing to monitor ground deformation over time. In recent years, advanced techniques and algorithms have been developed for the application of InSAR in a more accurate manner along with the continuous availability of new satellite data. In this research, we propose the use of a developed clustering algorithm for analyzing InSAR time-series data and face the superposition of effects inducing ground movements. The investigated area is in the Po Plain in northern Italy and it is characterized by massive groundwater production for various purposes and it also hosts an underground gas storage system. The focus of the research is the identification and the quantification of the seasonal and trend behavior related to aquifer exploitation. We selected the additive approach for decomposing the time-series obtained from InSAR and applied the k-means clustering algorithm (Morissette and Chartier, 2013) over the seasonal and trend components. The results showed different seasonal behaviors attributed to areas with varying water production, rainfall precipitation and structural geology. The trend was analyzed and compared to the existing literature proving the reliability of this method.
The quantification of ground deformation due to each main source is of paramount importance for a reliable prevision of each phenomenon via the calibration of dedicated numerical models. The results of the research will be used to discriminate and quantify the effects of water
production from the effects of gas storage operations and they will allow the calibration of dedicated 3D numerical fluid-flow and stress-strains models
Investigation of ground movements induced by water withdrawal via cluster-analysis applied to InSAR data
No full textRemote sensing methods (InSAR) provide advanced methodologies for detecting and precisely measuring ground deformations (GD) of anthropogenic origin like trend and seasonal aquifer-system response to exploitation and recharge.
We developed an algorithm that relies on the decomposition and clustering analysis of time series of GD to characterize the deformative behavior over a specific area due to anthropogenic activities related to water production. The vertical movements for monitoring points (MP) derived from InSAR measurements were decomposed into their seasonal (S) and trend (T) components. S is suitable for analyzing seasonal behavior of GD induced by oscillatory phenomena like aquifer withdrawal for agricultural purposes and seasonal rainfall recharges. T is more useful for measuring the impact of anthropogenic activities with a more linear and continuous behavior in time. Subsequently, the cluster analysis groups for all the MPs, which are grouped according to their similarities in S or T components, allows to define and quantify the deformative behavior of the system and the areal extent of the phenomenon.
We applied this method to different areas in Emilia-Romagna in northern Italy characterized by strong superposition between groundwater production and other anthropogenic activities such as gas /storage. We focused on identifying different behaviors of the time series related to the different activities. We compared the results form cluster analysis with ancillary info such as: water well positions, amount of fluid production, rainfall precipitation, the structural geology and the land use maps of the studied areas comparing the different seasonal behaviors related to those attributes. The analysis of the trend and seasonal component allowed us to verify our results and the reliability of this method with data from literature.
The results of this work enable us to quantify and isolate the effects of water production on GD from other anthropogenic effects
Fluid Production Dataset for the Assessment of the Anthropogenic Subsidence in the Po Plain Area (Northern Italy)
Get PDFFluid produced/injected volumes from/into underground natural formations and their spatial allocation play a key role in addressing the superposition of anthropogenic subsidence effects, but the definition of coherent datasets is usually very challenging. In this paper, the creation of a gas and water production dataset for the Po Plain area in northern Italy is presented, focusing on the Emilia-Romagna region (an industrialized, highly-populated area characterized by rapid subsidence). The produced volumes and their spatial/temporal allocation are gathered from different sources, analyzed, and organized via dedicated georeferenced maps. The geological framework of the Po Plain is delineated, with attention to the superficial aquifers. Reference ranges of petrophysical and pseudo-elastic parameters are reported for both aquifer and reservoir formations. Water extractions from the superficial unconsolidated sediments are widespread, both in space and time; instead, primary gas production and underground storage of natural gas, involving deeper formations, are spatially and temporally well constrained. Drastic increases in water production and high concentrations of gas production temporally coincided between the 1950s and 1970s. The ‘hotspots’ of the strongest superposition are recognized in Piacenza, Ferrara, Bologna, and Ravenna provinces. Qualitative and quantitative information represent a reference source for both Oil and Gas Societies and Regional/National authorities in addressing the subsidence analysis to plan the field production life and predict the environmental consequences
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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