[Analysis of Space-temporal Evolution and Spatial-related Network Structure of Ecological Efficiency in China]

In-depth analysis of the spatial and temporal evolution of eco-efficiency and the structural characteristics of its spatial correlation network can provide a scientific basis for promoting the synergistic and high-quality development of the region. Based on the super-efficiency SBM model with non-expected outputs, the eco-efficiency of 30 provinces (excluding data from the Tibet Autonomous Region, Hong Kong, Macao, and Taiwan) in China is measured and quantified in terms of spatial and temporal evolution from 2013 to 2022. With the assistance of the modified gravitational model and the social network analysis method, the spatial correlation network correlation characteristics of the eco-efficiency in the provinces are analyzed. The study found that: ① The overall level of China's eco-efficiency has risen in the past ten years, showing a positive development trend, but the development of eco-efficiency among provinces was unbalanced, with obvious spatial differences, showing a spatial pattern of "low-high-low" from the north to the south. The hyper-variable density was the main source of the differences in eco-efficiency. ② There was an obvious spatial correlation of ecological efficiency among provinces and regions, which was manifested in a complex spatial network structure, but this correlation was relatively weak. ③ Shanghai, Beijing, Jiangsu, and Guangdong provinces and cities were located in the core of the eco-efficiency network, assuming the role of central actors and playing the role of "bridge," while the central and western provinces were at the periphery of the network. ④ There were obvious correlation and spillover effects among different segments in the eco-efficiency network, but the composition of the segments varied significantly, and the interactions among the segments in 2022 were mainly characterized by "net benefit" and "net spillover." In conclusion, the results of this study can provide a scientific basis for the construction of the network of regional synergistic high-quality development and inter-provincial eco-efficiency and provide practical support for the development of global eco-optimization and differentiation strategies.