Analysis of Effects of Sponge City Projects Applying the Geodesign Framework

This study aims is to verify the effects of sponge city projects focusing on the aspect of water pollutant control and urban flood control, applying the geodesign framework as an integrated planning method that can evaluate alternatives against the impacts of the designs. The study analyzed the effects of sponge city projects in Harbin, Quzhou, and Sanya, China. Three LULC scenarios are proposed based on the geodesign framework, and the spatial distribution and quantitative values are simulated by the InVEST NDR model and urban flood model study. By comparing different scenarios, the study proved the current sponge project could improve the water pollutant control capability by 11–18% and the stormwater control capability by 0.4–6.3%. If the city-wide green infrastructure network is introduced with sponge projects, the water pollutant control capability can increase by 9–15% and the stormwater control capability can increase by 0.8–2.9%. These results show that the current sponge projects can improve the city’s sustainability and be helpful strategies to fight climate change and global warming.