Research on the “economy-society-environment” sustainability of urban agglomerations in the Yellow River Basin

Assessing the coordinated development of the economy, society, and environment is fundamental to achieving urban sustainability and reducing regional disparities. This study examined 72 cities across seven urban agglomerations in the Yellow River Basin. A comprehensive evaluation system was constructed based on the United Nations Sustainable Development Goals (SDGs), employing the Coupling Coordination Degree Model (CCDM) and Random Forest algorithm (RFA)-SHapley Additive exPlanations (SHAP) model to analyze the spatial distribution characteristics, spatiotemporal evolution, and driving factors of the coordinated development level of the “economy-society-environment” (ESE) system from 2007 to 2022. Results indicate significant spatial differentiation in the sustainable development levels of urban agglomerations in the Yellow River Basin. Cities with higher SDG scores are concentrated in the eastern coastal areas of the Shandong Peninsula urban agglomeration (SPUA), while those with lower scores are predominantly distributed in the Ningxia Yellow River urban agglomeration (NXUA) and the Lanzhou-Xining urban agglomeration (LXUA). The overall degree of coupling coordination of the ESE system increased from 2007 to 2022. Among the urban agglomerations, the SPUA and the Hohhot-Baotou-Ordos-Yulin Urban Agglomeration (HBOYUA) are in a barely balanced development state, while core cities such as Xi'an and Zhengzhou have achieved a state of slight balance. However, development levels remain uneven within and across urban agglomerations. Driving factor analysis shows that the urban sprawl index, economic development level, and urbanization level are the primary factors influencing economic sustainability. Social sustainability is mainly driven by fiscal expenditure per unit area, urbanization level, and economic development level. Environmental sustainability is closely related to the proportions of water bodies, cropland, and impervious surfaces. This study provides theoretical support for the sustainable development of urban agglomerations in the Yellow River Basin.