Understanding the role of urban environment in SMS innovations: Evidence from the Yangtze River Delta

Urbanization has significantly altered hydrological cycles, increasing impervious surfaces and exacerbating flooding. To address these challenges, developed nations have pioneered stormwater management systems (SMS). In China, the "Sponge City" concept was initiated to enhance water management through natural accumulation, infiltration, and purification. This study explores SMS innovations in the Yangtze River Delta (YRD), a key area for China's sponge city pilot projects. Using spatial analysis methods such as Moran's I, Kernel Density Estimation, and standard deviation ellipse, the research examines the spatial distribution of SMS innovations from 2009 to 2021. The findings indicate that environmental innovations are concentrated in cities like Shanghai, Nanjing, and Hangzhou, with high innovation concentrations positively influencing neighboring areas. Further research is needed to explore the relationship between environmental innovations and regional innovation capabilities for comprehensive solutions in environmental protection and sustainable urban development.