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MAPPATURA DELLE AREE ALLAGABILI MEDIANTE MODELLO GEOMORFOLOGICO PER IL BACINO DEL TORRENTE ENZA
No full textMappatura di scenari di allagamento conseguenti a rotte arginali
No full textSOMMARIO. Dopo un’analisi delle principali caratteristiche dei modelli SWE utili ai fini della
mappatura di scenari di allagamento conseguenti a rotte arginali, viene presentato un codice
parallelo 2D sviluppato dagli scriventi in ambiente CUDA e descritta in dettaglio l’attività svolta
per simulare la rotta arginale verificatasi sul fiume Secchia il 19 gennaio 2014. Viene infine
presentato il progetto di ricerca RESILIENCE (REsearches on Scenarios of Inundation of Lowlands
Induced by EmbaNkment Collapses in Emilia), volto a definire un data‐base informatizzato
di possibili scenari di allagamento per la mappatura del rischio residuale conseguente a
rotte arginali nel tratto medio‐basso del fiume Po e dei suoi principali affluenti. Esso può costituire
un utile strumento a disposizione degli Enti preposti alla gestione dell’emergenza per programmare
in corso di evento piani di intervento più mirati per la salvaguardia di vite umane e
beni materiali
Assessment of Flood Hazard Mapping Using a DEM-Based Approach and 2D Hydrodynamic Modeling
No full textDEM-based approaches for assessing flood-prone areas have recently gained extensive
attention due to their parsimony and cost-effectiveness. This work aims to test the capability of
the Geomorphic Flood Index (GFI) to delineate flood-prone areas and the results performances
while downscaling the calibration map. The accuracy was tested by examining the sensitivity to
the exponent of the power function linking the flow depth in the river network and the upslope
contributing area. Two approaches were selected: the first consisted of calibrating the GFI using a
flood map generated through a 2D-SWE hydrodynamic model. The second consisted of correlating
water depths with their corresponding upslope areas. The geomorphological model is able to
effectively delineate flood susceptibility areas which, although on average larger than that obtained
using the hydrodynamic model, provide a good starting point for any subsequent in-depth analysis.
After calibration, an Objective Function of 0.21 and an Area Under the ROC Curve AUC = 92%,
which is among the highest if compared with other cases in the literature, were obtained. Positive
feedback was also obtained using a calibration map that covers only a rather limited portion of the
basin. However, the small values of the scaling exponent obtained after calibration with the first
method indicate substantial independence of the river depths from the upslope contributing areas.
This leads to the belief that a simple power function is not particularly suitable for describing the
relationships between these two variables
A GPU-Accelerated Shallow-Water Scheme for Surface Runoff Simulations
Get PDFThe capability of a GPU-parallelized numerical scheme to perform accurate and fast
simulations of surface runo in watersheds, exploiting high-resolution digital elevation models
(DEMs), was investigated. The numerical computations were carried out by using an explicit finite
volume numerical scheme and adopting a recent type of grid called Block-Uniform Quadtree (BUQ),
capable of exploiting the computational power of GPUs with negligible overhead. Moreover, stability
and zero mass error were ensured, even in the presence of very shallow water depth, by introducing
a proper reconstruction of conserved variables at cell interfaces, a specific formulation of the slope
source term and an explicit discretization of the friction source term. The 2D shallow water model
was tested against two dierent literature tests and a real event that recently occurred in Italy for
which field data is available. The influence of the spatial resolution adopted in dierent portions of
the domain was also investigated for the last test. The achieved low ratio of simulation to physical
times, in some cases less than 1:20, opens new perspectives for flood management strategies. Based
on the result of such models, emergency plans can be designed in order to achieve a significant
reduction in the economic losses generated by flood events
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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