Evaluating the Effectiveness and Potential of Urban Planning for Enhancing Flood Resilience in the Pearl River Delta, China

While flood adaptation measures are critical to cope with flood impacts, there is a lack of quantitative evaluations of the effectiveness and potentials of the various measures. Even in flood risk assessments that incorporate spatial attributes, the influence of adaptation planning and policies in enhancing flood resilience is often underestimated. Urban planning, including master plans, land use plans, and infrastructure plans, reflects the government’s vision for the city’s future and encompass targeted risk management strategies that will be implemented. This study explores whether and how much urban planning, when effectively implemented, can sufficiently mitigate the anticipated future flood risks. Focusing on the nine cities as a metropolitan area at the Pearl River Delta (PRD) in China, we did a comprehensive collection of  various planning schemes that modify original terrain conditions, alter natural hydrological process, store and drain flood water, as well as warn and relief people and properties in flood. Measures in the plans are integrate into a flood risk assessment model. By conducting flood simulations under various future climate scenarios, we evaluate the effectiveness of urban planning across the nine cities in PRD region. The findings indicate that flood risk in the PRD cities can be significantly reduced once the planned measures are implemented. The findings underscore the  role of urban planning as a key representative of governance tools in strengthening flood resilience, while demonstrating the potential of government-led resilience-building policies and initiatives. Combing with extensive individual actions in flood emergency, future flood loss in the PRD area may demonstrate less increase than flood risk does. This research also presents a methodological framework for incorporating planning measures into flood risk simulation to evaluate their effectiveness in enhancing flood resilience.