Trade-off efficiency: Linking urban socioecological quality with land use efficiency from return on investment perspective

Effectively coordinating urban development and urban socioecology is crucial for achieving sustainable development goals. However, efficacious measurements and assessment frameworks in this field are still insufficient. This study proposes a novel metrics, termed trade-off efficiency, which measures the relationship between urban development and urban socioecology from a return on investment perspective. Using three major Chinese cities, Zhengzhou, Nanchang and Changsha as a case study, we initially quantified regional socioecological states, including urban heat island effect, air quality, habitat quality, and green space accessibility, at a 1 km2 grid level. We also measured regional land use efficiency at the same resolution. The super-slack-based measure model was employed to examine the trade-off efficiency. The results revealed that the regional socioecological quality, in general, exhibits an opposite spatial pattern to the land use efficiency, underscoring the practicality of quantifying the trade-off efficiency from a return on investment perspective. The trade-off efficiency, which decreases from the inside to the outside, demonstrates a similar spatial pattern as the land use efficiency, implying that urban development and urban socioecology may conform to the Environmental Kuznets Curve. The proposed framework, with its fine resolution, holds the potential to serve specific urban planning and assist decisionmakers in targeting low-efficiency areas.