1,721,094 research outputs found
A digital elevation model based method for a rapid estimation of flood inundation depth
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Un’analisi della variabilità delle aree contribuenti al deflusso di piena mediante modello idrologico distribuito
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Un esempio di modellistica integrata per l’analisi dei processi che controllano la frequenza delle piene fluviali
No full textCurve di danni e prevenzione di perdita negli edifici storici per la valutazione del rischio d’inondazione.
No full textLa relazione tra azioni di alluvione e danni sugli edifici, utilizzando funzioni di danno basate su parametri costruttivi e di resistenza delle diverse tipologie di fabbricato, è necessaria per un'efficace valutazione della vulnerabilità in caso di alluvione. In questo senso, è possibile determinare il danno alla micro scala, di singolo edificio, ed anche alla macro scala di uno comparto di edifici con caratteristiche simili. Questo approccio nella valutazione del rischio di alluvione delle strutture storiche è particolarmente critico, poiché le curve di danno basate su specifici parametri costruttivi e caratteristiche materiali debbono tener conto anche delle tecnologie storiche di costruzione. Inoltre, le previsioni di perdita aiutano a determinare il rapporto costo-beneficio dell'intervento necessario considerato quanto i costi di conservazione siano elevati. La ricerca ha preso in considerazione i dati di ispezione raccolti nel 2017 nel centro storico di Guimarães, in Portogallo, tramite un'analisi dettagliata delle caratteristiche materiali e delle tecnologie costruttive di un edificio storico portoghese rappresentativo. Grazie a questi dati è stato possibile sviluppare le curve di danno e le previsione delle perdite, in modo da fornire una panoramica dell'applicazione e dell'analisi sistematica che questo approccio consente.Relationship between flood action and damage in buildings, using damage functions based on constructive and resistance parameters of different types of buildings, is required for a reliable loss prediction and an effective vulnerability assessment front flood risk in built environments. In this sense, is possible to determinate damage in both scales, micro- scale, of single building, or macroscale, of a stock of buildings with similar characteristics. This approach in flood risk assessment of historical structures is valuable, since that, damage curves based on specific constructive parameters and material characteristics permit a most accurate assessment, that permit safeguard not only the structure itself but also the historical technologies of construction. Furthermore, loss predictions help to determinate the cost-benefit of the intervention needed, contribution that in heritage field is also favourable, especially for investors, since the costs of conservation use to be high. On the basis of the inspection data collected on 2017 in the historical centre of Guimarães, Portugal, and with a detailed analysis of material characteristics and constructive technologies of a representative historical Portuguese building; damage curves and loss prediction were developed on this research, in way to give an overview of the application and systematic analysis that this approach permits
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
Metrics for the quantification of seeding characteristics to enhance image velocimetry performance in rivers
Full text linkRiver flow monitoring is essential for many hydraulic and hydrologic applications related to water resource management and flood forecasting. Currently, unmanned aerial systems (UASs) combined with image velocimetry techniques provide a significant low-cost alternative for hydraulic monitoring, allowing the estimation of river stream flows and surface flow velocities based on video acquisitions. The accuracy of these methods tends to be sensitive to several factors, such as the presence of floating materials (transiting onto the stream surface), challenging environmental conditions, and the choice of a proper experimental setting. In most real-world cases, the seeding density is not constant during the acquisition period, so it is not unusual for the patterns generated by tracers to have non-uniform distribution. As a consequence, these patterns are not easily identifiable and are thus not trackable, especially during floods. We aimed to quantify the accuracy of particle tracking velocimetry (PTV) and large-scale particle image velocimetry (LSPIV) techniques under different hydrological and seeding conditions using footage acquired by UASs. With this aim, three metrics were adopted to explore the relationship between seeding density, tracer characteristics, and their spatial distribution in image velocimetry accuracy. The results demonstrate that prior knowledge of seeding characteristics in the field can help with the use of these techniques, providing a priori evaluation of the quality of the frame sequence for post-processing
Influence of climatic and soil factors on flood frequency distributions in Southern Italy
No full textThe flood frequency estimation in ungauged basins requires the development of innovative statistical tools aimed to improve the available techniques for risk assessment. This research is aimed to better understand and classify the hydrological processes underlying the flood generation exploiting the theoretical model of Iacobellis and Fiorentino [9]. The effects of climatic and physiographic basin features on the main variables of the cited theoretical flood probability distribution are analyzed focusing on 33 gauged basins in a wide area of Southern Italy. Results provide interesting information for the research of an analytical derivation of a flood frequency distribution whose parameters are directly related to climatic and physiographic basin characteristic
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