Uncertainty analysis in sewer system performance evaluation

Selezione del tempo di ritorno ottimale della pioggia di progetto delle reti di drenaggio urbano

A performance based approach for the analysis of urban water distribution systems under drought conditions

The present study proposes some performance indicators for analysing urban water distribution system characterised by intermittent supply service. Specific indicators have been proposed for investigating the reduction of quality of water service under resources scarcity conditions. A modelling procedure has been implemented in order to allow for analysing complex network schemes in which users self adapt to scarcity conditions. The procedure has been applied to analyse the performance of an existing supply system in Palermo (Italy). The network and users’ behaviour in intermittent distribution conditions have been monitored in order to calibrate the model and verify the reliability of the p…

Una metodologia per la selezione del tempo di ritorno ottimale della pioggia di progetto delle reti di drenaggio urbano

L'obiettivo del presente lavoro è quello di definire una metodologia per l'individuazione del tempo di ritorno ottimale della pioggia di progetto dell reti di drenaggio urbano.

Analisi economica degli interventi distribuiti di gestione dei deflussi urbani

L’applicazione degli interventi distribuiti di gestione dei deflussi urbani è stata effettuata finora in maniera piuttosto disomogenea in Europa ed in particolare in Italia, probabilmente anche in seguito alle difficoltà legate alla valutazione dell'efficienza idraulica ed economica di tali interventi. Obiettivo del presente lavoro è quello di analizzare l’aspetto economico di alcune BMP per quanto riguarda sia i costi di realizzazione sia quelli di manutenzione, nell’ottica della valutazione dell'efficienza delle BMP e delle problematiche relative alla implementazione di sistemi di drenaggio nel contesto della pianificazione territoriale. Attraverso la classificazione, la descrizione e l’a…

Estimation of urban structural flood damages: the case study of Palermo

Abstract The estimation of flood damage is a fundamental step in the economic analysis of a flood control projects. In particular, frequency–damage functions, derived from the hydrologic, hydraulic and damage relationships, are one of the fundamental pieces of information upon which expenditure decisions are based. The aim of this study has been to develop an empirical frequency–damage relationship, obtained by means of detailed local studies, which could be a judgement tool for flood mitigation measures in strongly urbanised drainage areas. Monuments and other estates having a cultural or artistic significance have been specifically taken into account. The analysis has been carried out for…

Urban drainage analysis for flooding mitigation

Urban drainage and sustainable cities: how to achieve flood resilient societies?

This paper tries to describe the main developments of urban flood forecasting and modelling. Currently, several new technologies are available for flood monitoring, modelling and mitigation and several paradigms suggest the adoption of greener approaches to urban storm water management. These tools and new approaches can be easily adaptable to new developments where the entire urban drainage system can be suited to follow a more sustainable way to drain storm water. The challenge for the future is instead aimed to apply this new philosophy to existing urban areas where the application of new tools and technologies requires high costs and such approaches have to be prepared by constructing a…

In condizioni di scarsità delle risorse intervenire sulla domanda o sull'offerta

Uncertainty analysis of the influence of rainfall time resolution in the modelling of urban drainage systems

In urban drainage modelling, rainfall temporal variability can be considered as one of the most critical knowledge elements when dealing with rainfall–runoff models input data. The rainfall data temporal resolution usually available for practical applications is often lower than that requested for the rainfall–runoff simulation in urban areas, greatly compromising model accuracy. The present paper evaluates the influence of rainfall temporal resolution on the uncertainty of the response of rainfall–runoff modelling in urban environments. Analyses have been carried out using historical rainfall–discharge data collected for about 10 years in Parco d'Orleans experimental catchment (Palermo, It…

Mitigation of urban flooding: A simplified approach for distributed stormwater management practices selection and planning

The urbanization process and the hydraulic insufficiency of drainage systems are two of the most common causes of urban flooding. In some technical regulations, distributed stormwater management practices (DSMPs) are regarded as a solution for urban flooding problems. They can prevent the formation of runoff, dispose of it locally, or dampen its peak before it reaches the drainage system. Due to their diffuse localization and the wide number of available solutions, the evaluation of their efficiency in terms of flood reduction is very difficult. The methodology proposed in the present paper relies on the concept that the mitigation effects of DSMPs can be expressed as a function of the chan…

Selection of the Optimal Design Rainfall Return Period of Urban Drainage Systems

Abstract The aim of this work is to define a methodology to identify the optimal rainfall return period for the design of urban drainage systems. The choice of the optimal return period is made minimizing the total costs of the system: the sewer network is dimensioned for a set of possible design rainfall return periods, and the corresponding construction, maintenance and operation costs are evaluated. For each scenario, the total expected damage from flooding caused by rainfall events with return period greater than the design one is then estimated by hydraulic simulation. This methodology has been applied to a small urban catchment in Palermo (Italy).

In condizioni di scarsità delle risorse intervenire sulla domanda o sull’offerta