Flood Resilience of Urban River Restoration Projects: Case Studies in Hong Kong

As a flood mitigation strategy, most of Hong Kong's river channels were straightened and lined with concrete to maximize their drainage capacities, but at the cost of ecological and aesthetic values. To reclaim these and still meet engineering demands, some nature-based solutions have been introduced to revitalize the rivers. However, there are concerns about the resilience of the restored rivers under heavy rainstorms. In this paper, a framework and process for resilience analysis is proposed, based on which resilience analysis was performed on two river restoration cases from the perspectives of engineering resilience, system resilience, and complex adaptive system resilience. The analysis framework and process were found to be useful in generating technical and managerial insights into the resilience of the river restoration projects. Based on the analysis results, proactive design and adaptive operation management strategies are recommended. Although resilience analysis in this paper was performed in the context of river restoration projects, the framework and process may be applicable to other civil infrastructures.