Spatial impact effects of China’s land urbanization on ecological environment quality

Urbanization is characterized by systemic society transformation from agricultural to urban, particularly for land urbanization. Rapid land urbanization has posed a serious threat on the national food security in China, due to the “ghost cities”, less arable land, and ecological deterioration. Land use patterns and resource allocation efficiency are also dominated ecological environment. It is often required to assess the spatiotemporal pattern effects of land urbanization on ecological environment quality in sustainable agriculture. In this study, an evaluation framework was constructed to measure the trajectories of land urbanization and ecological environmental quality index (EEQ). Empirical data was collected from 284 prefecture-level and above cities in China. Bivariate spatial autocorrelation analysis and spatial Durbin models were also employed to investigate the spatial dependence, direct impacts, and indirect spillover effects in the urbanization-environment nexus. The results show that: (1) Land urbanization levels rose steadily in China during the study period. Both land urbanization and ecological quality indices were improved continuously, with a “core-periphery” hierarchical spatial structure. The ecological environment quality index increased from 0.661 to 0.792, with an average annual growth rate of 0.93%, driven by the green spaces with the environmental governance. (2) Four patterns were observed in the spatial correlation between land urbanization and ecological environment quality: “high-high synergy”, “high-low imbalance”, “low-high heterogeneity”, and “low-low lag”. The intensity of spatial correlation increased, and the distribution pattern gradually evolved from the scattered to clustered configuration. Therefore, the high-high synergy and low-low lag areas were expanded with the contraction of high-low imbalance and low-high heterogeneity areas. Spatially, the positive effect of land urbanization on ecological environment quality shared a continuous strengthening trend. (3) Contrary to local benefits in specific zones, the overall land urbanization continued to significantly inhibit ecological environment quality at regional scale. Furthermore, the Spatial Durbin Model (SDM) analysis verified the negative spatial spillover effects. Among them, GDP, IND, and TEC were positively contributed to ecological quality, whereas POP showed the significant negative. Environmental impacts demonstrated spatiotemporal heterogeneity: Temporally, short-term negative effects outweighed long-term impacts, while spatially, eastern regions exhibited positive effects, whereas, central-western and north-eastern regions showed the negative impacts. The disparities were attributable to multiple factors, including locational advantages, development models, ecological carrying capacity, and policy interventions. Differentiated land-use measures were finally proposed to harmonize urbanization and environmental health. Allocation efficiency and institutional safeguards were strengthened for ecological protection in sustainable urban land. Theoretically, spatial spillover effects and spatial-temporal heterogeneity were integrated into a unified analytical framework, thus refining the urbanization-environment interactions. SDM was effectively reduced endogeneity and spatial dependence, while effects of decomposition revealed the specific direct and indirect pathways. Practically, the finding can provide empirical evidence and decision-making support for differentiated regional sustainability, territorial spatial optimization, and ecological compensation.