6533b856fe1ef96bd12b3131

RESEARCH PRODUCT

Uncertainty analysis in sewer systems performance evaluation

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description

In recent years, in order to analyse complex urban drainage systems and to identify the most effective measures for improving their efficiency, many parameters, or indicators, have been defined and many methodologies have been proposed in order to quantify sewer systems performance in the most objective and general way. However, some uncertainty arises in these methodologies due to choices which the user has to take in applying the procedure. Thus, performance analysis results are affected by operator experience and they are mainly useful for comparison between different scenarios applied to the same system. In the present paper, a statistical analysis of sewer systems performance has been carried out, aimed to quantify the uncertainty depending on user subjective selections needed during the procedure and affecting the assignment of PI level of service. Considering historical statistically independent rainfalls as input, the proposed methodology applies Monte Carlo simulations to generate sewer system global performance for different penalty curve shapes. The statistical analysis of the obtained frequency\342\200\223performance relationships allows for improving the robustness of the method and for increasing the user confidence in the methodology results. The proposed analysis has been applied to a real case study in Palermo (Italy).