1,721,241 research outputs found
A methodology for assessing spatio-temporal dynamics of flood regulating services
Full text linkThe effects of land use alteration, migration and urbanization are key aspects in flood management, as human activities can strongly influence the capacity of ecosystems to provide flood regulating ecosystem services and determine their demand. This study analyzes spatio-temporal dynamics of flood regulating ecosystem services to support watershed management planning. A methodology for mapping the supply and demand of flood regulation is proposed and applied to the Arno River basin, in central Italy. The spatial explicit analysis of flood regulating ecosystem services supply is carried out with SWAT - Soil and Water Assessment Tool, whose outputs are synthetized by two indicators to evaluate the retention capacity of each land use class originating from CORINE data sets. Quantification of demand for flood regulating ecosystem services is based on flood hazard classes derived from the existing local flood management plans (i.e., PAI-Piano per l'Assetto Idrogeologico and PGRA-Piano di Gestione del Rischio Alluvioni). Supply and demand data are then combined to obtain budget maps of flood regulating ecosystem services and their evolution, between 1990 and 2018. The results show how both demand and supply of ecosystem services have changed in the last decades, highlighting the main hotspots at the catchment and subcatchment scales. With the increasing urbanization, the demand values have grown in the Arno floodplains, where residential, industrial and commercial zones are located. At the same time, land use changes have altered the water regulation supply, resulting in a generalized decrease of the basin capacity to provide flood regulation services. The maps and tables obtained show the fundamental role of forest and other vegetated areas whose protection is a priority to assure future flood regulation and associated co-benefits (e.g., regulation of air quality, reduction of erosion, improvement of water quality, wood fuel). The assessment of flood regulating here proposed is a powerful tool for decision makers to improve flood regulation and provides a sound base of knowledge to identify and locate flood prevention and mitigation measur
Floods and food security: A method to estimate the effect of inundation on crops availability
No full textThe inner connections between floods and food security are extremely relevant, especially in developing countries where food availability can be highly jeopardized by extreme events that damage the primary access to food, i.e. agriculture. A method for the evaluation of the effects of floods on food supply, consisting of the integration of remote sensing data, agricultural statistics and water footprint databases, is proposed and applied to two different case studies. Based on the existing literature related to extreme floods, the events in Bangladesh (2007) and in Pakistan (2010) have been selected as exemplary case studies. Results show that the use of remote sensing data combined with other sources of onsite information is particularly useful to assess the effects of flood events on food availability. The damages caused by floods on agricultural areas are estimated in terms of crop losses and then converted into lost calories and water footprint as complementary indicators. Method results are fully repeatable; whereas, for remote sensed data the sources of data are valid worldwide and the data regarding land use and crops characteristics are strongly site specific, which need to be carefully evaluated. A sensitivity analysis has been carried out for the water depth critical on the crops in Bangladesh, varying the assumed level by ±20%. The results show a difference in the energy content losses estimation of 12% underlying the importance of an accurate data choice
IL PROGETTO M-MASTER PER IL MASTER SUL RISCHIO IDRAULICO DELL'ATENEO DI FIRENZE
No full textIl Progetto M-Master nasce da una collaborazione fra il Dipartimento di Ingegneria Civile dell'Università degli Studi Firenze e la Società Consortile E-Form. Il progetto è stato realizzato per alcuni master dell’Ateneo Fiorentino per promuovere una formazione di tipo “blended learning”. L’obiettivo è riuscire a rendere fruibili i master prevalentemente a distanza, integrando didattica, servizi di consulenza, fonti documentarie e bibliografiche e assistenza in presenza distribuita sul territorio nazionale. Nell’ambito del progetto M-Master si inserisce il master sul Rischio Idraulico proposto in risposta al crescente sviluppo di nuove metodologie e tecniche di indagine che richiedono di integrare l’attività di ricerca applicata con quella di formazione superiore favorendo l’accesso dei partecipanti ai laboratori e alle attrezzature scientifiche e utilizzando, per la divulgazione, le nuove opportunità offerte dalla tecnologia dell’informazione della formazione “e learning”. In tale contesto, basandosi sull’esperienza maturata nei 3 anni di attività, è stato dato avvio alla sperimentazione di una “biblioteca digitale aperta” sul rischio idraulico, strutturata come un ambiente virtuale a sostegno dell’apprendimento
Understanding adaptive capacity to extreme events and climate change in urban areas
No full textUrban environments are often the “hotspots” of vulnerability to extreme events in terms of human and material costs. This fact reflect a number of factors, including climate change, rapid urbanization often poorly planned, and, importantly, a general lack of assessment tools and measures that would enhance resilience and adaptation capacities of urban centers. The international and interdisciplinary cooperation are considered in order to improve adaptive capacity and resilience
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
Impacts of Rainfall Data Aggregation Time on Pluvial Flood Hazard in Urban Watersheds
Full text linkPluvial floods occur when heavy rainstorms cause the surcharge of the sewer network drainage, representing one of the most impacting natural hazard in urban watersheds. Pluvial flood hazard is usually assessed considering the effect of annual maxima rainfall of short duration, comparable with the typical concentration times of small urban watersheds. However, short duration annual maxima can be affected by an error of underestimation due to the time resolution as well as the aggregation time of the rainfall time series. This study aims at determining the impact of rainfall data aggregation on pluvial flood hazard assessment. Tuscany region (Central Italy) is selected as a case study to perform the assessment of the annual maxima rainfall underestimation error, since the entire region has the same temporal aggregation of rainfall data. Pluvial flood hazard is then evaluated for an urban watershed in the city of Florence (Tuscany) comparing the results obtained using observed (uncorrected) and corrected annual maxima rainfall as meteorological forcing. The results show how the design of rainfall events with a duration of 30 min or shorter is significantly affected by the temporal aggregation, highlighting the importance of correcting annual maxima rainfall for a proper pluvial flood hazard evaluation
Uncertainty partition challenges the predictability of vital details of climate change
No full textDecision makers and consultants are particularly interested in “detailed” information on future climate to prepare adaptation strategies and adjust design criteria. Projections of future climate at local spatial scales and fine temporal resolutions are subject to the same uncertainties as those at the global scale but the partition among uncertainty sources (emission scenarios, climate models, and internal climate variability) remains largely unquantified. At the local scale the uncertainty of the mean and extremes of precipitation is shown to be irreducible for mid and end-of-century projections because it is almost entirely due to internal climate variability (stochasticity). Conversely, projected changes in mean air temperature and other meteorological variables can be largely constrained, even at local scales, if more accurate emission scenarios can be developed. The results were obtained by applying a comprehensive stochastic downscaling technique to climate model outputs for three exemplary locations. In contrast with earlier studies, the three sources of uncertainty are considered as dependent and, therefore, non-additive. The evidence of the predominant role of internal climate variability leaves little room for uncertainty reduction in precipitation projections; however, the inference is not necessarily negative, since the uncertainty of historic observations is almost as large as that for future projections with direct implications for climate change adaptation measures
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
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