1,720,998 research outputs found
Run up on beaches through simplified shallow water model
No full textAccurate evaluation of wave run-up on beaches is a critical issue for coastal flooding studies. During extreme events, the maximum wave run-up, caused by very long (frequently non-breaking) waves, may exceed the crest of the coastal protection structures or dunes and inundate the protected inland area. This event may be simulated by a flood propagation model, recently published by the authors, that solves a simplified form of the Shallow Water Equations (SWE). The simplification mainly consists of linearizing bottom friction and neglecting advection. This study investigates on the relevance of the latter terms and on the model ability in predicting wave run-up on impermeable beaches. Numerical simulations of run-up induced by solitary non-breaking waves on a gentle-sloping planar beach are compared to the results found by Synolakis (1987) on the basis of an experimental study. For the numerical simulations, only 21 tests of the 40 experiments carried out by Synolakis (i.e. all the non-breaking waves) are considered. A good agreement between the numerical and the experimental maximum run-up was found for all the tested waves. In order to verify the magnitude and the effects of the advection terms in the SWE, some simulations are repeated considering and neglecting this term. The hypothesis of neglecting convective terms is found appropriate
Analysis of overflow and wave overtopping of the Scardovari lagoon levees
No full textThis paper studies the Scardovari lagoon (Po Delta, Italy) in relation to the coastal flooding of the low-lying rear area, that is protected by earth levees. The paper aims at identifying the critical stretches, also in view of climate changes. Three different scenarios are investigated considering both the future sea-level rise and the rate of subsidence that affects the area. Field measurements, numerical models and analytical tools are used to define the overflow and wave overtopping. It is found that the critical stretches that require mitigation measures are mainly located in the North-eastern sector
Analysis of the vulnerability of the lagoon levees of the Po Delta to coastal flooding in a changing climate
Full text linkThis study analyses the coastal flooding hazard of the Po River Delta (Italy) area and develops a credible strategy for adaptation to climate change. The Po Delta, located in the north-western Adriatic Sea, is a peculiar coastal environment of great ecological and productive importance. The inland area is protected by different lines of levees, some of which are situated along river branches and others along the perimeters of the lagoons. Following the 1966 extreme storm event, the levees were raised and reinforced. Now, the predicted sea level rise and the subsidence affecting the area pose new warnings that require the possible upgrading of the levees surrounding the lagoons. Extensive field measurements and surveys are available and have been used to classify the 84 km long lagoonal levees. A set of numerical wave and surge results allows the overtopping and overflow discharges to be calculated with analytical tools to highlight the critical stretches along the defence. By 2070, considering the worst IPCC SSP5-8.5 scenario and a typical subsidence rate (6 ÷ 10 mm/y), it is found that ∼36 km of levees require mitigation measures to face the future projections and ∼15 km of them are associated with high level of hazard. The most vulnerable area is the Scardovari lagoon in the southern part of the Delta. The adaptation strategy includes raising the crest of the levees, improving the armour layer and, eventually, constructing low-crested structures or other wave attenuation options within the lagoons
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
L'indagine sul Successo Formativo. Progetto ReSFor - Azione 2. Resoconto di ricerca 02
No full textIl rapporto si riferisce al Progetto ReSFor - Rete per il Successo Formativo - della Regione Lombardia ID 274450 affidato all'Istituto Superiore di Ricerca Educativa dell'Università Pontificia Salesiana di Mestre (VE
Variations on the Author
Full text link“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
Full text linkWe 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
Adaptation works to avoid the flooding of Piazza San Marco (Venice): Physical model tests to evaluate overtopping discharge
Full text linkAccording to the management of the Mo.S.E. system, the water level in the Venetian lagoon is maintained below a certain threshold, that however does not guarantee the complete defense of the main Piazza. Flooding of the Piazza is presently tolerated, although limitedly to a minor extent, and can/will be avoided only thanks to additional adaptation works. One of the possible flooding mechanisms is the wave overtopping, and this note investigates the efficiency, as possible mitigation option, of a small temporary barrier placed along the S. Marco quay
Overtopping and stability of a rubble mound breakwater with Coreloc armour under oblique cyclonic waves
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