Assessing inter-industrial ecosystem service flows and economic benefits of sponge city: A comprehensive input-output analysis

Abstract

Sponge cities, crucial components of urban eco-infrastructure, play a vital role in mitigating urban waterlogging, enhancing water resource management, and improving ecosystem resilience. However, the economic and ecosystem services benefits of low-impact development (LID) facilities in cities remain unclear. This study classified sponge city facilities as distinct subsectors within an input-output framework and develops a partial closure model to assess their economic and ecological impacts during construction and operation phases. Additionally, an ecological satellite account for carbon sinks, SS removal and water conservation is compiled to quantify the economic value of ecosystem services. Using Xining City's sponge city project as a case study, the findings reveal that the primary sector benefits most from water conservation (34.58 %), while government consumption (58.9 %) is the largest indirect beneficiary of suspended substance (SS) removal and carbon sequestration, reflecting the public good nature of environmental benefits. Sponge city construction stimulates economic activity, with total inputs exceeding four times the direct investment, driving growth in hidden sectors such as food processing, finance, and energy distribution. Additionally, the carbon sequestration from sponge city facilities offsets construction-related emissions within 4.07 years, though only 41.78 % of maintenance-phase emissions are balanced by carbon sinks, emphasizing the need for long-term sustainability measures. These results highlight sponge cities' unique role in economic restructuring, distinguishing them from traditional infrastructure. The study provides a framework for integrating ecological and economic indicators, supporting evidence-based urban planning and the transition toward a sustainable, eco-economic development model.