Resilience in urban drainage risk management systems

Resilience is defined here considering the behaviour of an urban drainage risk management (UDRM) system in terms of its response and recovery under different rainfall events focusing on institutional and social aspects. A set of indicators is defined to operationalise definition for UDRM systems. To quantify the indicators, a hierarchical fuzzy system is developed to consider uncertainties in the UDRM system's social and institutional parameters and also to prevent the curse of dimensionality. The proposed scheme is tested on a real case study in Tehran in order to evaluate the effectiveness of some urban drainage plans to improve the current urban drainage system in terms of resilience. The results show that the presented indicators may be used as decision making criteria to help urban authorities select urban drainage options based on the behaviour of the UDRM system under different rainfall events.