Quantifying the UDS Hydraulic and Social Resilience to Flooding: An Index‐Based Approach vs. a Parameter‐Based MCDM Method

Various approaches to quantifying resilience have sparked debate in past years. This study measures the social and hydraulic resilience of an Urban Drainage System (UDS) using two methodologies, i.e., a proposed index‐based framework and a parametric‐based Multi‐Criteria Decision Making (MCDM) method. The former positions flexibility as a key property of the resilience concept, and after quantifying four characteristics of a flexible system, measures the flood resilience based on quantifying the two resilience components, i.e., flexibility and resistance; while. The latter calculates the resilience through a linear combination of the actual values and relative weights for different UDS sub‐characteristics which best describe the resiliency of the system. The methodologies were applied to a basin, focusing on flooding as a disaster, to quantitatively evaluate the behavior of UDS under both single‐event and long‐term precipitation. The results of both methods were indicative of a relatively low level of flood resiliency for the UDS in the studied area. Among different scenarios examined for the studied region, using Best Management Practices (BMPs) was turned out to be an effective adaptive measure to enhance the UDS resilience to a higher level.