Extreme rainfall changes induced by future climate in Mediterranean area

Extreme rainfall events have large impacts on society and are likely to continue to do so under predicted future climate change. Indeed, extreme precipitations show intensification in many regions of the world and this is of key importance to society as a result of the large impact of flooding. Thus, for planning and management decisions of the hydraulic infrastructures, accurate estimates of precipitation magnitudes at different durations are needed. Moreover, extreme precipitation events represent an increasing threat to society under global warming and are among the most serious challenges. In fact, future climate change is likely to lead to the change of extremes events that will become…

Utilizzo delle statistiche direzionali per la caratterizzazione delle precipitazioni intense in Sicilia

Le precipitazioni intense costituiscono la fase finale dei processi che interessano i flussi atmosferici e di umidità nonché l'interazione di questi ultimi con l’orografia. La caratterizzazione delle precipitazione intense risulta essenziale al fine di valutare i rischi per la società e per le infrastrutture idrauliche. Stime attendibili di tali eventi sono dunque necessarie per la quantificazione e per la gestione del rischio idrologico. Lo studio qui presentato mira alla valutazione di elementi per la caratterizzazione degli eventi intensi nel territorio siciliano, sulla base dell'analisi statistica e spaziale del dataset di precipitazioni massime annuali registrate dalla rete pluviografi…

Sviluppo di un sistema di monitoraggio per lo studio delle dinamiche meteorologiche nell'area urbana di Palermo.'

Combining single polarization X-band radar and ground devices for hydrological applications

Recently, the Department of Civil, Environmental, Aerospace Engineering, and Materials (DICAM) of the University of Palermo (Italy) has installed several devices for the monitoring of precipitation for the urban area of Palermo. These devices include a single polarization X-band weather radar, a rain gauge network spread over the urban area, and a laboratory site where advanced precipitation devices (an optical disdrometer, a weight rain gauge, and a weather station) are available. Given the ensemble of measurements retrieved by sensors, a set of models for the combination of data has been developed in order to exploit their joint usage. The disdrometer information have been exploited for t…

Regional frequency analysis of extreme rainfall in Sicily (Italy)

Annual runoff assessment in arid Mediterranean watersheds under the Budyko framework

The solution of many practical water problems is strictly connected to the availability of reliable and widespread information about runoff. The estimation of mean annual runoff and its interannual variability for any basin over a wide region, even if ungauged, would be fundamental for both water resources assessment and planning and for water quality analysis. Starting from these premises, the main aim of this work is to show how using the Budyko framework is possible to map the mean annual surface runoff and derive the pdf of the same variable in arid watersheds. As a case study, the entire island of Sicily, Italy, is here proposed. First, time series data of annual rainfall, runoff and r…

The impact of climate change on extreme precipitation in Sicily, Italy

Increasing precipitation extremes are one of the possible consequences of a warmer climate. These may exceed the capacity of urban drainage systems, and thus impact the urban environment. Because short-duration precipitation events are primarily responsible for flooding in urban systems, it is important to assess the response of extreme precipitation at hourly (or sub-hourly) scales to a warming climate. This study aims to evaluate the projected changes in extreme rainfall events across the region of Sicily (Italy) and, for two urban areas, to assess possible changes in Depth-Duration-Frequency (DDF) curves. We used Regional Climate Model outputs from Coordinated Regional Climate Downscalin…

Derivation of Rainfall Thresholds for Flash Flood Warning in a Sicilian Basin Using a Hydrological Model

Abstract The damages caused by flash floods are among the most onerous in terms of loss of lives and damage to properties. Derivation of rainfall threshold is one of the approaches commonly used for the development of flash flood warning systems. Specifically, rainfall threshold is the rainfall amount that, for a given basin area and duration, is enough to cause flooding and, therefore, it indicates the maximal sustainable rainfall for a basin. The aim of this paper is deriving flash flood-rainfall thresholds for a Sicilian basin (Italy) throughout a deterministic approach. The conceptual hydrological model TOPDM was used to estimate the amount of rainfall that, for given duration, hydrolog…

Annual runoff assessment in arid and semiarid Mediterranean watersheds under the Budyko's framework

The solution of many practical water problems is strictly connected to the availability of reliable and widespread information about runoff. The estimation of mean annual runoff and its interannual variability for any basin over a wide region, even if ungauged, would be fundamental for both water resources assessment and planning and for water quality analysis. Starting from these premises, the main aim of this work is to show a new approach, based on the Budyko's framework, for mapping the mean annual surface runoff and deriving the probability distribution of the annual runoff in arid and semiarid watersheds. As a case study, the entire island of Sicily, Italy, is here proposed. First, ti…

Regional frequency analysis of extreme precipitation for Sicily (Italy)

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…