## 3 Results
### Decoupling Analysis  
Regarding the decoupling analysis between population-urbanization-ecological environment subsystems, firstly, the average decoupling index between population and urbanization is 3.7, which indicates that the urbanization process is significantly faster than the population urbanization process. Figure 11a also shows that all provinces are in the upper part of the first quadrant and on the second quadrant, and the provinces are in a strong decoupling state, with Jilin, Heilongjiang, Fujian, Guangdong, Hainan, and Sichuan in the second quadrant, indicating that the 10-year population index assessment is  
Figure 10: The comparison of the coupling coordination degree under spatial urbanization. Figure 9: The comparison of the coupling coordination degree under economic urbanization. declining. In Jilin, Heilongjiang, and Sichuan, there is a strong decoupling of urbanization and population processes, mainly due to population outflow and stagnant or negative population growth, while Fujian, Guangdong, and Hainan are in a period of rapid coastal development, with a large influx of population, causing the quality of the population to decrease and urban development to expand. Therefore, the disorderly urban expansion needs to be further curbed in order to protect the sustainable development of cities. Secondly, the average decoupling index between population-ecology and the environment is 0.79, demonstrating that overall, the impact coefficient of the population urbanization index continues to rise, and the negative impact on the ecological environment is increasing. Looking at the provinces (Figure 11b), the differences among provinces are still large, among which Shandong, Henan, Hunan, Yunnan, Shaanxi, and Ningxia are in the lower part of the first quadrant and are weakly decoupled, indicating that the population growth is faster than the improvement in the ecological environment, which is not conducive to the sustainable development of the new type of urbanization. Inner Mongolia, Gansu, Guangxi, and Xinjiang are in the fourth quadrant, which indicates strong decoupling. This shows that the expansion of the population leads to the consumption of regional energy resources, an increase in pollutant emissions, and the consumption of the ecological environment. This increases the burden of the regional environmental capacity, further increases the ecological risk, and also leads to the deterioration of ecological environment quality. Heilongjiang, Jilin, Guangdong, Fujian, Hainan, and Sichuan are in the third quadrant, while Beijing, Tianjin, and Liaoning are in the upper part of the first quadrant, which is the strong decoupling type, indicating that the development of the population and ecological environment is on the road of sustainable development and the environmental problems are constantly improving. Finally, from the perspective of urbanization and the ecological environment (Figure 11c), most provinces are located in the lower part of the first quadrant and the fourth quadrant, except Tianjin and Henan, which shows that the process of urbanization has exerted great pressure on the environment and affected the sustainable development of regional ecosystems. Among them, Inner Mongolia, Guangxi, Gansu, and Xinjiang are in a state of strong decoupling, and ecological environment retrogression appears. The development mode of urbanization is unsustainable or the ecological environment needs to be repaired urgently. Next, we analyzed from the perspective of environmental pressure. As demonstrated by environmental pressure-population and environmental pressure-urbanization, most provinces of the two are in an expansion state, indicating that most provinces face the dual pressure of environmental pressure and urbanization and population expansion. However, at the same time, we also found that Yunnan, Shanghai, Ningxia, and Xinjiang are in the second quadrant (Figure 11d,e), which is strong decoupling.