An Event-Based Resilience Index to Assess the Impacts of Land Imperviousness and Climate Changes on Flooding Risks in Urban Drainage Systems

Abstract

Assessing the resilience of urban drainage systems requires the consideration of future disturbances that will disrupt the system’s performance and trigger urban flooding failures. However, most existing resilience assessments of urban drainage systems rarely consider the uncertain threats from future urban redevelopment and climate change, which leads to the underestimation of future disturbances toward system performance. This paper fills in the gap of assessing the combined and relative impacts of future impervious land cover and rainfall changes on flooding resilience in the context of a densely infilled urban catchment served by an urban drainage system in Salt Lake City, Utah, USA. An event-based resilience index is proposed to measure climate change and urbanization impacts on urban floods. Compared with the traditional resilience metric, the event-based resilience index can consider climatic and urbanized impacts on each urban flooding event; the new resilience index assist engineers in harvesting high-resolution infrastructure adaptation strategies at vulnerable spots from the system level to the junction level. Impact comparison for the case study shows that impervious urban surface changes induce greater effects on the system performance curves by magnifying the maximum failure level, lengthening the recovery duration, and aggravating the flooding severity than rainfall intensity changes. A nonlinear logarithmic resilience correlation is found; this finding shows that flooding resilience is more sensitive to the land imperviousness change due to urban redevelopment than rainfall intensity changes in the case study. This research work predicts the system response to the disturbances induced by climate change and urban redevelopment, improving the understanding of impact analysis, and contributes to the advancement of resilient urban drainage systems in changing environments.

Resilient Urban Flood Management: A Multi-Objective Assessment of Mitigation Strategies

“…The increasing impervious rates resulted in a median EI of −0.02. This supports the conclusion of Li et al [43], which demonstrates a great impact of system performance regarding urban flood resilience by changing the impervious rate. The median EI for all reference climate change scenarios and reference combined scenarios are in a similar low range between −0.95 and −0.94.…”

“…Past studies mainly focused on the evaluation of the flooding area [27,30,41], the resilience of stormwater systems [42][43][44], or urban flood resilience [45]. However, in the context of urban flooding, a single objective assessment is not suitable for evaluating the highly integrated process due to the dependencies of numerous physical processes [46,47].…”

A Novel GIS-SWMM-ABM Approach for Flood Risk Assessment in Data-Scarce Urban Drainage Systems

“…While inadequate infrastructure design plays a role, a broader perspective is essential to address these challenges [4,5]. The dynamic nature of urban hydrology and the potential impacts of climate change on rainfall patterns must be considered [7,8,73]. As the system is relatively new, a comprehensive focus on adaptation and resilience becomes crucial, emphasizing strategies like LID practices [26,27].…”