1,720,957 research outputs found
Approccio multidisciplinare per la valutazione della propensione al dissesto idrogeologico. I bacini del rio Badde Manna e del Rio di Banari (Sardegna NW, Italy)
No full textMultidisciplinaty approach to landslide: the Rio Badde Manna and Rio Banari river basin, NW Sardinia, Italia
No full textViene presentata e discussa l’applicazione di una metodologia multidisciplinare per la valutazione
della propensione al dissesto idrogeologico; lo studio viene condotto su base quantitativa,
in quanto impostato:
– sull’impiego di una valutazione di tipo parametrico dei fattori geo-ambientali che influenzano
il dissesto;
– sulla zonizzazione degli stessi mediante misure sperimentali;
– sull’attribuzione oggettiva di pesi (codici numerici) relativi ai fattori;
– sulla valutazione finale del fenomeno tramite sovrapposizione (overlay mapping) dei tematismi
di base e restituzione cartografica in ambiente G.I.S.
La metodica parametrica multidisciplinare, sviluppata in ambiente GIS, è un efficace strumento
per la determinazione della propensione al dissesto idrogeologico e da tempo viene applicata
in diversi contesti territoriali italiani. Tale metodica è da anni nostro oggetto di studio al fine
di applicarla, sperimentarla ed adattarla alle peculiarità del territorio della Sardegna. Essa si basa
sull’osservazione dell’area in studio e sul rilievo, anche speditivo, di dati relativi all’assetto
territoriale, ai processi ambientali, all’interazione antropica, etc. e prende spunto da modelli
già sperimentati [RER, 1977; CARG, 1992] dai quali si discosta innovativamente per il tentativo
di valutare in maniera più oggettiva i parametri presi in considerazione. Fondamentali sono stati
in questo senso il lavoro di fotointerpretazione e le verifiche in situ per i dati relativi al fattore
uso del suolo, con l’attribuzione di pesi alle tecniche impiegate dall’uomo per la lavorazione del
terreno, e le analisi su campioni di suolo. La validazione del modello proposto è stata effettuata
mediante il confronto con le aree storicamente colpite da fenomeni di dissesto. Il presente lavoro
vuole mettere in evidenza l’importanza dell’approccio multidisciplinare per valutazioni legate
ai fenomeni di dissesto idrogeologico, con lo scopo di validare un modello operativo, a scala di
bacino, che sia ripetibile in altri contesti territoriali e fruibile dai tecnici operanti nel settore.This study presents and discusses the application of a multidisciplinary method for flood and
landslide susceptibility assessment. It is conducted on a quantitative basis and comprises:
– a parametric evaluation of the geo-environmental factors influencing susceptibility tendency;
– zonation and parametrization of natural and anthropogenic factors using experimental data;
– assignment of numerical weight to the homogeneized parameters;
– ultimate assessment of susceptibility proneness overlaying the basic thematic maps and
map rendering in a GIS environment.
The multidisciplinary parametric method developed in a GIS environment is an efficient tool for
determining flood and landslide proneness and is applied in various regional contexts in Italy.
The methodology has been widely studied by applying, testing and adapting it to the
peculiarities of Sardinian terrains. It is based on the field data and on reconnaissance surveys
to gather data regarding regional setting, environmental processes, human/environment
interaction and so forth. It takes cue from models already tested but innovatively differs from
these in its attempt to evaluate the parameters considered more objectively. In this sense
aerial photointerpretation and in situ data control for the land use factor assigning weights to
agricultural practices and analysis of soil samples proved essential. The proposed model has
been validated through comparison with areas historically affected by floods and landslides.
This paper intends to highlight the importance of a multidisciplinary approach to natural
susceptibility assessment for operational validation of the basin scale model, repeatable for
other regional contexts and usable by professionals in this sector
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
Traditional approach and remote sensing techniques in the development and implementation of desertification indicators
No full textThe monitoring of desertification in the affected areas requires adequate tools able to
provide reliability, objectivity and replicability in processes assessment. Desertification
indicators explains how processes evolve over time and vary in space and they can
synthetically explain the state and trend of desertification. The development of projects
focused on the application of indicators is an important step to design reliable and improved
desertification monitoring systems.
In this context, the present work illustrates some results achieved in the framework of
European consolidated initiatives focused on development and implementation of
desertification indicators based on both traditional approaches (DESERTLINKS) and
remote sensing techniques (DESERTWATCH). The DESERTWATCH project created a
user-tailored operational system to assess and monitor desertification and its trend over
time on the base of Earth Observation technology. The project integrated consolidated
procedures and algorithms into an operational automatized system, based on the integration
of different environmental indicators and remote sensing data. The aim of DESERTLINKS
project was to develop a desertification indicator system for Mediterranean Europe. All the
indicators are now published in a specific web-based database
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
Mapping Mediterranean rangeland condition using MODIS NDVI time series
No full textThe aim of this study was to evaluate the potential of MODIS NDVI time series analysis for evaluating Mediterranean rangeland conditions. Field data were collected in the season 2006-2007 and 2007-2008 in 25 and 42 sites respectively. The analyzed sites were classified in three rangeland degradation classes, on the basis of expert knowledge. Quantitative indicators of rangeland condition were also measured in a subset of sites. We analyzed the relationship between MODIS NDVI time series and measured properties of rangeland vegetation, in order to assess which factor related to vegetation condition may have a major influence on the NDVI seasonal profile. The Local NPP Scaling (LNS) method was then applied and its potential for discriminating the degradation classes was evaluated. Finally, LNS maps were generated for the period 2000-2008 and analyzed to identify areas which exhibited persistently low LNS values. Results indicate that the LNS method applied on MODIS NDVI time series allows mapping Mediterranean rangeland conditions in central Sardinia and could represent an important tool for preventing land degradation phenomena
Il telerilevamento nella valutazione delle misure agroambientali. Il biologico in Sardegna
No full textLa Commissione Europea ha recentemente stabilito criteri e regolamenti in merito alla valutazione
degli impatti delle Misure agroambientali (MA) relativi al miglioramento della qualità del suolo e
dell’acqua. Per dare una risposta esaustiva ed oggettiva alle esigenze di valutazione e monitoraggio
sono necessari indicatori efficaci. In Sardegna, il principale impatto dell’esercizio delle attività
zootecniche sui processi erosivi e sulla fertilità dei suoli è dato dalla diffusione delle pratiche
aratorie in condizioni pedologiche e morfologiche non idonee, fenomeni che in alcuni casi sono
stati favoriti da incentivi non adeguatamente calibrati. A questo proposito, vengono presentati
alcuni indicatori finalizzati alla valutazione dell’impatto degli incentivi erogati alle aziende
biologiche sarde del settore zootecnico, ottenuti mediante un’analisi multitemporale (1994-2004)
basata su immagini Landsat, acquisite in date tali da evidenziare l’evoluzione delle superfici arative
in tre differenti fasi di applicazione delle misure agroambientali
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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