Probabilistic modeling of sustainable urban drainage systems

Abstract Sustainable Urban Drainage Systems (SUDS) include strategies and solutions for distributed stormwater management control. They are strongly encouraged, especially in highly urbanized areas that suffer the combined effect of impervious surfaces increase extreme rainfall events due to urbanization growth climate change. Their integration into traditional urban drainage systems can mitigate flood risk pollution receiving water bodies. The main goal SUDS is restore natural balance by increasing infiltration evapotranspiration processes promoting rainwater harvesting reuse. This paper proposes an analytical-probabilistic approach modeling applicable different systems. Developed equations allow estimating runoff residual storage probability evaluating efficiency volume both terms control and, depending on type, emptying time or needs supply. considers possibility consecutive chained rainfalls; this feature relevant SUDS, often characterized low outflow rates. Relating characteristic parameters a probabilistic level (the Average Return Interval, ARI) makes formulas interesting be used design practice. An application two case studies confirmed goodness proposed method.