Based on the concept of high-quality development, this paper constructs an urban ecological welfare evaluation framework, measures the urban ecological welfare performance in Jiangsu Province from 2005 to 2019 using a stochastic frontier production function model, and conducts a spatial and temporal divergence feature analysis, combining a spatial panel econometric model and a threshold panel regression model to explore the spatial effects and mechanisms of urban ecological welfare performance. The results show that: (1) The urban ecological welfare performance in Jiangsu province has been increasing every year, and the spatial divergence between north and south is significant, with the overall trend of southern Jiangsu > central Jiangsu > northern Jiangsu. (2) The differences in urban ecological welfare performance among the three regions are gradually decreasing, with the high values expanding and the low values decreasing, and the urban ecological welfare performance in northern Jiangsu Province is gradually approaching that in southern Jiangsu Province, and the urban ecological welfare performance level tends to be balanced. (3) There are significant negative spillover effects of industrial structure, city scale, and economic development level on urban ecological welfare performance, as well as significant threshold effects of innovation level, industrial structure, foreign trade dependence, and economic development, and significant differences in the degree of influence of urbanization on urban ecological welfare performance under different threshold variables. (4) The urbanization and economic development levels are the fundamental factors driving urban ecological welfare performance improvement. Industrial structure optimization, city scale, technological innovation, and foreign trade dependence positively contribute to urban welfare performance, and government financial pressure constrains the performance level improvement. In the future, a long-term mechanism for high-quality green development should be constructed, spatial spillover channels should be continuously improved, welfare thresholds should be effectively circumvented, and urban ecological welfare performance should be promoted in a concerted manner.

To explore the spatiotemporal evolution characteristics of land use function and its correlation with social and economic development levels, taking the Yangtze River Delta region as an example, we quantified the multifunctional land use in the Yangtze River Delta region from 2000 to 2020 on a 5 km × 5 km grid and analyzed its spatiotemporal evolution characteristics. Each city’s comprehensive measure of economic development used the projection tracing method. Person’s method of interpretation was used for correlation between the spatial and temporal evolution of land use functions and the level of economic development and its coupling association. The study shows that: (1) from 2000 to 2020, the agricultural production function > ecological function > living function > non-agricultural production function in the Yangtze River Delta, but the non-agricultural production and living functions were gradually increasing, while the agricultural production and ecological functions were decreasing. In terms of spatial distribution, the agricultural production function decreases significantly around the built-up area due to the expansion of the built-up area. The non-agricultural production function strengthened around the central city in a network pattern and had a path-locking effect. Topography limits life functions, with high north and low south partially overlapping with non-agricultural production functions. Furthermore, the ecological function was high in the south and low in the north and continues to weaken due to the interference of human activities. (2) The spatiotemporal heterogeneity of different functions generated trade-offs/synergies. The trade-off relationship was prominent in agricultural production and non-farm production function and living function, and non-farm production and living function and ecological function during the study period. Conversely, agricultural production and ecological functions and non-farm production and subsistence functions were generally synergistic. Spatially, there was substantial spatial heterogeneity in the trade-off/synergy relationship between the two functions. (3) There was a clear correlation and spatial coupling between land use function indices and economic development levels in the whole region and sample zones. Still, the dynamic and regional nature of the evolution of land use functions results in sudden changes and jumps in different functions in space. Therefore, in the future integration of the Yangtze River Delta, it is necessary to pay comprehensive attention to the morphology of different land use functions and their synergy/trade-off relationship and to adjust the spatial governance strategy promptly according to the local conditions and the situation.

The dislocated development of population, land, and economy will disturb the urban system, cause ecological risk problems, and ultimately affect regional habitat and quality development. Based on social statistics and nighttime lighting data from 2000 to 2018, we used mathematical statistics and spatial analysis methods to analyze the change process of urbanization’s coupling coordination degree and ecological risk response pattern in the Yangtze River Delta. Results show that: ① From 2000 to 2018, the coupling coordination degree of urbanization in the Yangtze River Delta increased, with high values in Suzhou-Wuxi-Changzhou, Shanghai, Nanjing and Hangzhou regions. ② The ecological risk in the Yangtze River Delta weakened, and the vulnerability and disturbance of landscape components together constitute the spatial differentiation pattern of regional ecological risk, which presented homogeneous aggregation and heterogeneous isolation. ③ The overall ecological stress of urbanization in the Yangtze River Delta decreased. ④ The population aggregation degree, socio-economic development level and built-up area expansion trend contributed to the spatiotemporal differentiation of urbanization’s ecological risks through the synergistic effects of factor concentration and diffusion, population quality cultivation and improvement, technological progress and dispersion, industrial structure adjustment and upgrading. This study can provide a reference for regional urbanization to deal with ecological risks reasonably and achieve high-quality development.

The relationship between urbanization and ecology environment is a current research hotspot. Most literature to date focuses on the interaction between urbanization and a single component of the ecosystem (e.g., water, forests, and ecosystem services), while little attention has been given to the relationship between urbanization quality and ecosystem health. Accordingly, this paper used the entropy method and vigor—organization–resilience model to measure the urbanization quality and ecosystem health in Jiangsu Province. Based on the results, this paper analyzed the spatial-temporal pattern and evolution characteristics of the coordination degree between urbanization quality and ecosystem health in Jiangsu Province in 2000, 2005, 2010, 2015, and 2017 and then used the geographic detector and Tobit regression model to explore its internal driving forces and external influencing factors. The results show the following: 1. The changing trend of urbanization quality and ecosystem health in the Jiangsu Province share some traits; it first descends and then ascends; 2. The cities in Jiangsu Province are all between primary coordination and high-quality coordination. Central Jiangsu has the best coupling coordination degree, and Northern Jiangsu has the worst coupling coordination degree, but the overall coordination degree is on the rise; 3. The internal and external factors that drive the coordinated development of urbanization and ecosystem health differ based on periodic and regional characteristics. We need to tailor policies to ensure the sustainable development of the region.