Search results for " idrologia"
showing 10 items of 476 documents
Regional frequency analysis of extreme precipitation for Sicily (Italy)
2016
The analysis of extreme precipitation has always been included among most relevant hydrological applications because of the several important activities linked to the availability of tools for the estimation of extreme rainfall quantiles. These activities include the design of hydraulic civil structures and the evaluation and management of hydraulic and hydrological risk. In this study a frequency analysis of annual maxima precipitation measurements has been carried out for the area of Sicily (Italy). A typical hierarchical regional approach has been adopted for the parameter estimation procedure based on the L-moments method. The identification of homogeneous regions within the procedure h…
Evaluation and comparison of satellite precipitation estimates with reference to a local area
2011
Precipitation is one major variable for many applications. Satellite retrieval systems, raingauge network and radar systems are complement to each other in terms of their coverage and capability of monitoring precipitation. Satellite rainfall estimates systems produce data with global coverage that can provide information in areas for which data from other sources are unavailable.Without referring to ground measurement, satellite-based estimates can be bias. Although some gauged adjusted satellite precipitation products are developed, an effective way of integrating multi-sources of precipitation information is still a challenge. In this study we select a specific area in Sicily (Italy) hav…
A spatially distributed and physically based tool to modelling rainfall-triggered landslides
2009
Landslides are a serious threat to lives and property throughout the world. Over the last few years the need to provide consistent tools and support to decision-makers and land managers have led to significant progress in the analysis and understanding of the occurrence of landslides. The causes of landslides are varied. Multiple dynamic processes are involved in driving slope failures. One of these causes is prolonged rainfall, which affect slope stability in different ways. Water entering the ground beneath a slope always causes a rise of the piezometric surface, which in turn involves an increase of the pore-water pressure and a decrease of the soil shear resistance. For this reason, kno…
Mapping phycocyanin cells density of Planktothrix rubescens in freshwater reservoirs
2014
Geostatistical techniques for runoff mapping: an application to Sicily, Italy
2011
The availability of reliable and long time series of runoff data is fundamental for most of the hydrological analyses and for the assessment and the management of water resources even in condition of global climatic change. However, hydrologic data sets are often characterized by a short duration and also suffer from missing data values, mainly due to malfunctioning of gauging stations for a specific period. In order to overcome this problem and obtain long and continuous runoff time series, different models and methods have been previously developed and proposed. While some models, used to extent the streamflow record, are conceptual, empirical, regressive models based on the rainfall inpu…
Predisposizione di modelli previsionali della domanda idrica residenziale in condizioni di scarsità
2011
Un sistema informativo territoriale per la simulazione di una rete di drenaggio urbano con Flow1D
2011
Si propone un modello di simulazione monodimensionale delle reti di drenaggio urbano che operi all’interno di un software GIS e che consenta la realizzazione amichevole di un sistema informativo territoriale (SIT) della rete di drenaggio. Il modello, fisicamente basato, simula la formazione e la propagazione idraulica dei deflussi che si realizzano in ogni sottobacino, nonché la propagazione idraulica all’interno della sottostante rete fognaria. La connessione fra le due reti viene ricostruita attraverso il calcolo dei flussi verticali che si realizzano in corrispondenza dei pozzetti. Il modello è di tipo duale, in quanto rispetta l’interazione idrodinamica fra i deflussi nella rete stradal…
Analisi di storm tracking nell’area urbana di Palermo attraverso dati di pioggia ad alta risoluzione
2010
La conoscenza della distribuzione spaziale e temporale delle piogge di breve durata, nonché la loro cinematica, sono alcuni tra i fattori più importanti che stanno alla base dell’approssimazione dei modelli di trasformazione afflussi-deflussi nei bacini urbani. L'incertezza dovuta alla variabilità spaziale della pioggia può influenzare, ad esempio, le performance dei modelli di drenaggio urbano. Un'adeguata conoscenza della variabilità spaziale e temporale delle precipitazioni può essere considerata un passo fondamentale per un'esatta interpretazione dei processi idrologici di base che avvengono nei sistemi di drenaggio urbano durante gli eventi di pioggia intensi. L'analisi di tali informa…