Search results for "rainfall"
showing 10 items of 233 documents
Verifica delle equazioni disponibili per la stima della potenza cinetica delle precipitazioni naturali
2016
Nella memoria sono riportati i risultati delle indagini condotte utilizzando le distribuzioni dimensionali delle gocce di pioggia (DSD) rilevate mediante un disdrometro ottico installato, nel periodo Giugno 2006 - Marzo 2014, presso il Dipartimento di Scienze Agrarie e Forestali dell’Università degli Studi di Palermo e nel periodo Luglio 2015-Gennaio 2016 presso la stazione sperimentale di El Teularet in Spagna. Dopo aver aggregato le DSD per classi di intensità differenti in ampiezza, è stata determinata la potenza cinetica associando a ciascun diametro della DSD aggregata la relativa velocità di caduta calcolata mediante una relazione reperita in letteratura. I valori di potenza cinetica …
Dispositivo e metodo di misura delle caratteristiche energetiche delle precipitazioni
2018
Trends of some high quantiles of average and extremes inter-arrival timesand rainfall depths at daily scale for an Italian Sub-Alpine area
2015
Modeling of rainfall statistical structure represents an important research area in hydrology, meteorology, atmospheric physics and climatology, because of the several theoretical and practical implications. The statistical inference of the alternation of wet periods (WP) and dry periods (DP) in daily rainfall records can be achieved through the modelling of inter-arrival time-series (IT), defined as the succession of times elapsed from a rainy day and the one immediately preceding it. It has been shown previously that the statistical structure of IT can be well described by the 3-parameter Lerch distribution (Lch). In this work, Lch was successfully applied to IT data belonging to a sub-al…
Uncertainty connected with design rainfall for urban flood risk evaluation
2010
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…
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…
Rainfall Induced Landslides in Puerto Rico
2010
Derivation of rainfall thresholds for pluvial flood risk warning in urbanised areas
2016
In the recent past throughout the Mediterranean area, many extreme events such as floods, debris flows and landslides occurred. Mediterranean ephemeral streams have specific features compared to other river systems; their basins are small and highly torrential and may generate flash-floods (Camarasa-Belmonte & Soriano-Garcia, 2012). Moreover, the rapid transformation processes of urban areas induced the increase of catchment imperviousness and the derived increase of surface runoff generated during rainfall events. However, flooding events in urban areas occur quite frequently as a consequence of rain events of lower intensity than the design one, even in case of correct network dimensionin…