Ecological Benefits

• Relying solely on "source" strategies (such as reservoirs and wetlands) can reduce peak flow by up to 30% in moderate rainfall conditions, but in extreme rainfall events (such as the Zhengzhou rainstorm in 2021), "source" measures alone are insufficient and need to be combined with "conveyance" and "storage" strategies.
• "Conveyance" strategies, such as river widening and restoration of natural meanders, reduce flood intensity by about 10%.
• "Storage" strategies (such as expanding floodplains and raising building foundations) show higher efficiency, reducing flood disaster losses by 35%-50%.
• The SWA method, which integrates "source-conveyance-storage" measures, significantly enhances resilience, reducing the flooded area by 32% and flood disaster losses by over 50%.
• The study shows that integrated sponge basin management can enhance the resilience to floods and is a key strategy to address climate change and the challenges of extreme rainfall.

Data Source:

Peng X, Heng X, Li Q, Li J, Yu K. From Sponge Cities to Sponge Watersheds: Enhancing Flood Resilience in the Sishui River Basin in Zhengzhou, China[J]. Water 2022, 14, 3084.