Search results for " Idrologia"
showing 10 items of 476 documents
Rainfall depth-duration-frequency curves for short-duration precipitation events in Sicily (Italy)
2019
The design criteria of the hydraulic infrastructures, including, for instance, those for flood defense, urban drainage systems, reservoirs spillways and bridges, are based on the coupled analysis of the magnitude of rainfall events for a fixed duration and their estimated annual exceedance probability. The well-known rainfall depth-duration-frequency (DDF) curves, typically derived from the analysis of long historical annual maxima data series, synthesize the relationships between rainfall depth, duration and exceedance probability which is usually expressed as a return period. The time-resolution of rainfall data typically available for the construction of DDF curves and provided by gauges…
Daily rainfall statistics in Sicily (1920-2000)
2012
Rainfall characteristics are crucial for vegetation patterns formation and evolution in Mediterranean ecosystems. Changes in rainfall frequency and intensity could cause vegetation water stress for some plant species and benefit, at the same time, other species, driving coexistence and competition dynamics. The changes in the precipitation characteristics are sometimes more important than the changes in the total amount of precipitation in determining the partitioning between green and blue water with several implications for both the vegetation communities health and water resource management. Decreasing rainfall is a clear signature of climate change in Mediterranean countries. Annual and…
Caractèrisation des processus de seècheresse et de désertification à l'échelle régionale
2009
MODELLING WATER AND ENERGY BALANCE OF THE LAND-ATMOSPHERE SYSTEM USING HIGH RESOLUTION REMOTE SENSING DATA
2011
La rilevanza assunta dal risparmio della risorsa idrica negli ultimi anni ha spinto verso una corretta quanti cazione delle perdite legate al processo evapotraspirativo, al ne di una gestione parsimoniosa della risorsa stessa. In particolare nei sistemi agricoli soggetti a stress severo, sia la misura che la stima dell'evapotraspirazione (ET) ad un'adeguata risoluzione spaziale e temporale sono uno dei principali problemi da a rontare per la comunit a scienti ca. Recentemente, le tecniche di telerilevamento sono divenute un ulteriore strumento a supporto della modellistica idrologica distribuita; in particolare, le immagini acquisite nelle onde corte e nell'infrarosso termico risultano esse…
Evaluating the performances of an ecohydrological model in semi-arid river basins
2013
The EHSM (EcoHydrological Streamflow Model) is a conceptual lumped model aimed to daily streamflow simulation. The model, processing daily rainfall and reference evapotranspiration at the basin scale, reproduces surface and subsurface runoff, soil moisture dynamics and actual evapotranspiration fluxes. The key elements of this numerical model are the soil bucket, where rainfall, evapotranspiration and leakage drive soil moisture dynamics, and two linear reservoirs working in parallel with different characteristic response times. The surface reservoir, able to simulate the fast response of the basin, is fed by rain falling on impervious area and by runoff generated with excess of saturation …
Objective regional frequency analysis of extreme precipitation in Sicily, Italy
2015
The extreme events have large impacts on society and are likely to increase under climate change. For design and management decisions, particularly around hydraulic infrastructures, accurate estimates of precipitation magnitudes are needed at different durations. In this paper, the regional frequency analysis has been implemented and applied to precipitation data recorded in Sicily, Italy. Annual maximum series for rainfall durations of 1, 3, 6, 12 and 24 h provided by about 130 rain gauges were used. The Regional Frequency Analysis (RFA) has been used to identify the homogeneous regions using Principal Component Analysis (PCA) followed by a clustering analysis, through k-means, aimed to id…
INFLUENCE OF POSIDONIA OCEANICA MEADOW DENSITY ON FLOW RESISTANCE IN SHALLOW WATERS
2008
Aquatic vegetation considerably affects circulation in water bodies with influence increasing as the depth decreases. On the other hand, increasing use of mathematical circulation models for management of coastal sea waters, lagoons and marshes requires determination of such effects and in particular of flow resistance. A typical plant of inshore sandy beds, less than 40 m deep, in the Mediterranean Sea is Posidonia oceanica, which is constituted by a tuft of very thin and flexible ribbon-like leaves about 1 cm wide and up to 1.5 m long. This plant forms meadows with areal density usually ranging between 500 and 1000 plants/m2. Because of its characteristics, Posidonia oceanica constitutes …
Reti Neurali per la Realizzazione di Mappe di Suscettibilità per il Rischio Frana
2012
La valutazione della suscettibilità al dissesto rimane uno degli approcci più utilizzanti e più efficaci per l'analisi della pericolosità da frana. Come noto, la correlazione tra il fenomeno fisico ed i fattori predisponenti sulla base degli eventi accaduti in passato è il punto chiave di tale analisi. I metodi statistici, uniti con le tecnologie GIS, si sono rilevati in questi anni tra gli strumenti più idonei e più efficaci per la valutazione e la modellazione di tale correlazione. Tuttavia, questi metodi richiedono spesso ipotesi restrittive circa la distribuzione statistica dei dati che spesso non vengono rispettate. Per tale motivo si sono anche sviluppate metodologie alternative basat…
Influenza delle condizioni meteorologiche sulla propagazione elettromagnetica ed effetti sul servizio di telefonia mobile
2011
Heat waves and climate change: an application to Sicily (Italy)
2023
Nowadays, the effects of global warming are becoming increasingly evident and dangerous at every latitude of the planet. In such a context, the Mediterranean basin turns out to be a "hotspot". Reductions in precipitation, especially in the summer season, and increases in the intensity and frequency of extreme events, such as droughts and heat waves, have been observed in regions bordering the Mediterranean Sea in recent decades. In particular, heat waves may have numerous negative impacts on human health, environment, agriculture, and the energy sectors. Indeed, consecutive days with extremely high temperatures, combined with high humidity, poses a high health risk to the population. Moreov…