## 4 Discussion  
The interaction between urbanization and ecological resilience can be regarded as an interactive relationship between the urbanization system and its subsystems, and the ecological resilience system and its subsystems, which together constitute a large and complex system. This paper attempts to explain the mechanism of interaction between the four subsystems of demographic transition, economic transition, geospatial transition, and lifestyle transition in the urbanization system, and the three subsystems of base quality, structural stability, and ecological services in the ecological resilience system, and to summarize the characteristics of the double \"U\"-shaped coupling between urbanization and ecological resilience. Most scholars pay more attention to the empirical part of the analysis of the interaction between urbanization and ecological resilience [27; 28; 29; 30; 31]; therefore, mechanism analysis is the biggest contribution of this paper. However, this paper emphasizes the impact of urbanization on ecological resilience in the process of mechanism analysis, and the constraining and supporting role of ecological resilience on urbanization is less mentioned. The interactive coupling between urbanization and ecological resilience is not limited to the roles between the two systems internally; it may also be affected by the external roles of the system, such as global climate change and government policy interventions, which may be explicit or implicit, proximal or long-distance [57]; therefore, the mechanistic explanatory framework of this paper needs to be further improved. In the process of evaluating the level of ecological resilience, most scholars construct an ecological resilience evaluation index system based on urban statistical data [28; 30; 31], and this paper constructs an ecological resilience evaluation model with the data of land-use types as the core through habitat quality, landscape heterogeneity, and landscape connectivity, and ecosystem service value, which is a necessary attempt for the evaluation of ecological resilience that is difficult to quantify and helps to enrich the perspective of ecological resilience research and improve the method of ecological resilience evaluation. Some scholars have constructed a resilience evaluation model centered on the indicators of water resources and atmospheric systems that are worthy of reference [58; 59]. Incorporating the elements of land-use types, water resources, and atmospheric systems into the ecological resilience evaluation framework to evaluate ecological resilience more comprehensively in terms of base quality, structural stability, and ecological services is an issue that needs to be considered in further research. From the empirical analysis, the degree of coupled urbanization-ecological resilience coordination shows an increasing trend, which is consistent with the results of similar studies in other domestic urban agglomerations [26; 27; 30]. However, the difference is that urban agglomerations in coastal areas, such as the Pearl River Delta, have higher urbanization levels and faster enhancement rates, while ecological resilience levels are higher but are declining significantly. UANST, as an arid-zone urban agglomeration, has lower levels of both urbanization and ecological resilience, and the increase in the degree of coupling and coordination of urbanization and ecological resilience is mainly driven by the rapid increase in the level of urbanization, with demographic and geospatial aspects of the indicators being the main influencing factors, while changes in ecological resilience are more stable, with ESV being the main influencing factor.