Enhancing urban water ecological resilience through sponge city initiatives: Evidence from China
Paijie Wan, Hongjie Zhang
Abstract
Sponge city, a concept of urban planning and construction based on ecological principles, has garnered significant attention in recent years. The focal point of sponge city construction (SCC) is the water system-centered ecosystem. However, current assessments of the effectiveness of SCC primarily focus on partial analyses or case studies of specific regions, highlighting the need for more empirical work to explore the impact of sponge cities on the ecological environment. This study employs the entropy weight method to measure the water ecological resilience (WER) levels of various Chinese cities from 2009 to 2022 and then uses a multi-period difference-in-differences model to empirically investigate the impact of SCC on urban WER. Our results indicate that China's sponge city pilot policy has promoted the enhancement of urban WER, and this conclusion remains valid after robustness tests, including parallel trend tests, placebo tests, and entropy balancing. Compared to non-pilot areas, SCC has increased the WER of pilot cities by 2.66 %. In terms of policy effects, the impact of the sponge city pilot policy on WER continues to strengthen within five years after policy implementation. Further heterogeneity analysis results show that the improvement effect of SCC on WER is stronger in medium-sized cities, cities with higher precipitation, cities with higher urbanization rates, and cities with high fiscal capacity.