1. Introduction
Since the implementation of the reform and opening-up policy, China’s urbanization rate has increased rapidly, which has made significant contributions to the socio-economic development [
1,
2,
3]. However, urbanization is rooted in the ecological environment, and the growing demand for ecosystem services has driven its continuous expansion, posing inevitable challenges and pressures on urban ecosystems [
4,
5,
6]. On one hand, natural disasters resulting from ecological laws have adversely affected urban ecological systems; on the other hand, the extensive and unsustainable development practices of humans have led to ecological imbalances, undermining the environment for resilient urban development [
7,
8,
9]. This indicates a coupling and interactive relationship between the process of urbanization and ecological evolution. The introduction of the National New-type Urbanization Plan (2014–2020) marked a critical milestone in China’s transition to a new stage of urbanization. New-type urbanization (NU) has become both a practical consensus and a strategic guide for China’s socio-economic development in the new era [
6,
10]. Under the framework of sustainable development, exploring the mechanisms by which NU influences urban resilience and identifying the root causes of lagging resilience in certain cities can provide valuable policy insights for promoting the coordinated development of the two.
Resilience refers to a system’s ability to maintain structural or functional stability when it encounters external disturbances or changes [
11,
12,
13]. The concept of resilience was introduced by Lade et al. [
14] (2017) in the field of ecology as a measure of an ecosystem’s ability to absorb changes and disturbances while maintaining its overall function. Over time, the scope has broadened and the concept is now widely applied in the assessment of social services, economic development, and natural ecosystems [
13,
15,
16,
17]. Urban resilience refers to a city’s ability to quickly recover its original equilibrium state when subjected to internal and external shocks [
7,
8]. Cities are complex, multifaceted systems, and the ecological resilience, together with social, economic, and cultural elements, constitutes their overall urban resilience. There is a general consensus among researchers that the concept of urban ecological resilience (UER) refers to the speed or ability of urban ecosystems to return to a stable state after being subjected to internal and external perturbations.
With the continuous development of China’s society and economy, the characteristics and extension of urbanization are also evolving [
18,
19]. In contrast to traditional urbanization, which is characterized by crude and radical development, NU integrates high-quality economic development with improvements in the ecological environment, contributing to the optimal allocation of resources [
20,
21]. This may, in turn, impact the enhancement of UER. With the clarification of the concept of NU, the research focus has gradually shifted to the following challenges and key factors influencing the process of NU. (i) Placing human development rights at the core is a key factor and a strategic choice for addressing many of the complexities facing China’s NU. (ii) The construction of sustainable special towns is of great significance for promoting the coordinated development of urban and rural areas and accelerating the urbanization process. (iii) Promoting NU should focus on improving the planning of urban–rural spatial integration and development, strengthening the coordination, linkage, and coherence of urban–rural spatial planning.
Furthermore, economic development, industrial structure optimization, technological advancement, urbanization quality, and industrial agglomeration constitute the pivotal driving forces in the urbanization process [
2,
6,
18,
22,
23]. Previous investigations have predominantly examined the coupling relationship between urbanization and ecological resilience. These studies have consistently demonstrated that urbanization processes inevitably compromise ecological capacity, adversely affecting the demographic, economic, social, and spatial characteristics of urban areas, while simultaneously triggering ecological responses and altering the ecological conditions. However, the relationship between NU and ecological resilience remains poorly understood. Previous studies of ecological resilience have mostly focused on the provincial level, with few investigations at city level. Cities are often clustered based on geographic proximity, economic dependencies, and similar resource endowments, which in turn drive the convergence of regional urban ecological conditions [
24,
25]. Therefore, more comprehensive studies of UER are needed. The indicator systems used to assess and measure ecological resilience are not sufficiently clear, often emphasizing natural factors such as adaptability and restorative capacity while neglecting the risks posed by human social activities. Existing studies have rarely explored the dynamic spatiotemporal evolution and regional differences in UER. In summary, the existing research has provided a foundation for exploring the relationship between the NU and UER, with the gaps in the previous research being the focus of this study.
The main contributions of this study to sustainable urban development were as follows. (1) A theoretical framework was proposed to deepen the understanding of the mechanisms through which NU affects UER. (2) Based on the concepts and mechanisms of NU and UER, a five-dimensional evaluation index system was constructed for NU (population–economy–space–society–land) and a three-dimensional evaluation index system was constructed for UER (pressure–state–response: PSR), to present the resilience of ecosystems in adapting to NU development. (3) The heterogeneity and spatial spillover effects of the impact of NU on UER were investigated by regressing samples based on nationally defined criteria.
4. Empirical Results and Analysis
4.1. Spatiotemporal Patterns of the NU and UER, 2000–2022
4.1.1. Urban Ecological Resilience
Figure 2 shows the evolutionary characteristics of the spatial and temporal patterns of UER capacity in 281 prefecture-level cities in China from 2000 to 2022. The UER composite index of each city increased annually, with only slight decreases observed between 2000–2005 and 2020–2022. In 2000, the UER composite index of most cities was below 0.3432, indicating that the overall UER was relatively low. By 2005, the number of cities with an UER composite index below 0.3432 had increased, and nearly all cities in the western region had an index below this threshold. From 2010 onward, the UER composite index of cities nationwide increased significantly each year. By 2020, the UER capacity of cities across the country had stabilized and was greater than 0.3432, with some cities exceeding 0.4794. However, a marginal decline in the overall UER level was observed across Chinese cities by 2022. Nevertheless, the composite UER index for China continues to exhibit an upward trajectory overall.
4.1.2. New-Type Urbanization
Figure 3 depicts the spatiotemporal evolution of the composite index of NU for 281 prefecture-level cities in China from 2000 to 2022, indicating a steady and significant annual increase in NU levels nationwide. The development trajectory reveals a distinct spatial pattern: urbanization initially advanced along the eastern coastal areas, subsequently gained momentum in central China, and later expanded into the western regions. In 2000, NU indices across all regions were uniformly low, reflecting the generally underdeveloped stage of urbanization. By 2005, however, clear regional disparities began to emerge, with eastern coastal cities demonstrating rapid and sustained growth in their NU indices, while central, western, and inland eastern cities experienced comparatively moderate improvements. Over the following years, all regions exhibited consistent year-on-year growth, ultimately achieving relatively high and convergent levels of NU nationwide by 2022. This evolutionary process not only mirrors China’s broader trajectory of economic development and spatial restructuring but also shows a statistically significant and regionally differentiated correlation with UER patterns, highlighting the interactive dynamics between urbanization and sustainable development.
4.2. Benchmark Regression
Before conducting the benchmark regressions, a Hausman test was performed to determine whether to use a fixed effects or random effects model when analyzing panel data. The results are presented in
Table 4.
The final test results yielded a
p-value of 0.0002, i.e., less than 0.01. The null hypothesis was therefore rejected, indicating that the fixed effects model was a better fit for regression than the random effects model. Therefore, this study used a fixed effects model to regress Equation (3), and
Table 5 presents the benchmark regression results. Column (1) in the table shows the regression results without control variables, while column (2) displays the results after including control variables. The contrast between columns (1) and (2) highlights the impact of the control variables. To eliminate the effects of heteroskedasticity and correlations between samples within the same cluster, column (3) adjusts for robust standard errors in the ordinary least squares (OLS) estimation, and column (4) adjusts for cluster-robust standard errors to provide more accurate regression results. In columns (1) and (2), the regression coefficients of the independent variables are positive and pass the 1% significance test, suggesting that NU enhances overall UER, thus supporting Hypothesis 1.
Among the control variables, the regression coefficients for POP and NE were positive, indicating that excessively dense populations and rapid economic development lead to increased energy consumption and carbon emissions, which will harm the environment and reduce UER. The coefficients for SCI, WAG, and ASI were negative, indicating that excessive scientific research funding, increased residents’ incomes, and increased fixed asset investment do not significantly impact the city’s ecological resilience. The limited influence of financial support, the development of the fixed asset economy, and human capital in the study area on the optimal allocation of resources and environmental elements is a plausible explanation for this observation.
4.3. Endogenous Issue
The statistical properties of OLS estimators rely on the critical assumption that the error term is not correlated with the explanatory variables. If, for any reason, there is a correlation between the error term and the explanatory variables, the validity of our previous estimation results may be questioned. The possible reasons for such correlations include endogenous associations. Although the study controlled for variables affecting UER as much as possible, endogeneity due to omitted variables may still arise. Specifically, some control variables may exhibit an inverse relationship with NU. To address this, all control variables were lagged by one period to reduce potential endogeneity issues. The test results are presented in column (1) of
Table 6. The effect of NU in enhancing UER was still apparent, with the significance and signs of the regression coefficients being consistent with the benchmark regression results.
Second, cities with a higher UER tend to have more advanced digitalization and informatization technologies, which in turn provide NU with a “first-mover advantage”, creating an endogeneity issue in the causality judgment of the study. To mitigate this endogeneity, we employed the instrumental variable (IV) method. We selected the Internet penetration rate (IPR) and the cell phone penetration rate (CPPR) in 2018 as instrumental variables for NU. These values were measured by the number of Internet-connected households and the number of cell phone subscribers per 100 people, respectively. We then conducted an instrumental variables-two-stage least squares (IV-2SLS) regression, with the results presented in columns (2) to (5) of
Table 6. Specifically, columns (2) and (3) represent the IV-2SLS without control variables, with column (2) showing the first stage of the regression and column (3) showing the second stage. Columns (4) and (5) represent the IV-2SLS with control variables, with column (4) showing the first stage and column (5) showing the second stage. The results indicated that the hypothesis that NU enhances UER still holds and passes the significance test at the 5% level, regardless of whether control variables are included, after addressing the endogeneity issue.
Additionally, in the weak identification test of the instrumental variables, the Cragg–Donald F statistic exceeded the critical value at the 10% level in the Stock–Yogo weak identification test, and the test result rejected the hypothesis of a weak correlation of instrumental variables, indicating that the selection of instrumental variables was valid. In conclusion, the previous results remained robust after addressing the endogeneity issue.
4.4. Robustness Test
To further validate the robustness of these findings, additional tests were conducted by shortening the sample period, adjusting the observation window, excluding policy interference, and excluding the effect of outliers.
Shortening the sample period: Considering the impact of the COVID-19 epidemic on land use activities, the sample period was shortened to 2000–2019 for the regression analysis. The regression results, shown in column (1) of
Table 7, indicated that the regression coefficient for NU remained significantly positive after reducing the sample period, thereby confirming the robustness of the benchmark regression results.
Changing the observation window: In correlation studies, it is common practice to lag the explanatory variables by one or two periods in regression analyses to address the endogeneity problem and enhance the robustness of the model, leading to more accurate analytical results. In this study, we lagged the independent variable, NU, by two years to exclude potential confounding factors, thereby ensuring more reliable and accurate conclusions. As shown in column (2) of
Table 7, the regression coefficient for NU remained significantly positive after changing the observation window, confirming the robustness of the benchmark regression results.
Excluding policy interference: To eliminate the impact of localized policies on the comprehensive green transformation of cities’ ecological resilience, we conducted regressions on the remaining sample after excluding ten cities, including Wuxi and Fuzhou. As shown in column (3) of
Table 7, the benchmark regression results remained robust even after excluding policy interference.
Excluding the effect of outliers: To mitigate the impact of outliers on the regression results, we truncated the top and bottom 5% of the explanatory variables. The test results are shown in column (4) of
Table 7. The benchmark regression results remained robust even after excluding sample selection bias.
4.5. Mechanism Test
To verify Hypotheses 2 and 3, whether NU influences UER through STRUCT and INNO was investigated using the mediation effect model. Columns (1) and (3) of
Table 8 show the results obtained for estimating the impact of NU on STRUCT and INNO, respectively. The results showed that NU positively affected both STRUCT and INNO. From this, we inferred that the promotion of NU facilitates the optimization of innovation resource allocation by increasing the intensity of R&D investment. Additionally, NU contributes to STRUCT, thereby reducing energy consumption per unit of industrial added value.
Second, columns (2) and (4) show the effects of NU on UER after adding the mediating variables. The results indicated that both STRUCT and INNO positively impacted UER. Additionally, compared to the benchmark regression results, the regression coefficient for NU decreased but remained significant. This suggests that STRUCT and INNO play a role in mediating the effect. Specifically, the mediating effect of optimizing INNO was 0.063 (1.790 × 0.035). This was higher than the mediating effect of STRUCT, which was 0.010 (10.442 × 0.001).
To strengthen the credibility of the mechanism test results, we also used the Sobel and bootstrap tests to validate the findings. The test results, shown in
Table 9, indicated that both tests produced statistically significant results, confirming that NU can influence UER through STRUCT and INNO.
As discussed in the theoretical analysis above, NU helps optimize the allocation of limited social resources, which in turn promotes STRUCT and INNO. Struct and INNO ultimately further enhance UER. In summary, STRUCT and INNO are two key mechanisms through which NU enhances the ecological resilience of cities, thereby verifying Hypotheses 2 and 3.
4.6. Heterogeneity Analysis
4.6.1. Heterogeneity of Resource Endowment
The samples were divided into resource-based and non-resource-based cities for a group regression, based on their local government classification. The regression results in columns (3) and (4) of
Table 10 show that NU significantly improved UER in resource-based cities, but the effect was not significant for non-resource-based cities. Thus, Hypothesis 4 was verified. Compared to non-resource-based cities, resource-based cities face issues such as a single industrial structure, an excessive proportion of industrial land, and large areas of idle industrial land. Therefore, resource-based cities have more potential to optimize their land resource allocation, improve land use structure, and control environmental pollution, making it easier for NU to enhance UER.
4.6.2. Heterogeneity of Urban Zones
The regression results in columns (1), (2), and (3) of
Table 10 show that NU enhanced the ecological resilience of central cities more than it did for western and eastern cities, with the effect in western cities being slightly higher than in eastern cities. Hypothesis 5 was therefore supported. Compared to eastern cities, central and western cities, which are currently undergoing the implementation of the western development strategy and the rise of central China, respectively, are better positioned to demonstrate the impact of NU on UER. Moreover, the effect of urbanization on ecological resilience was more pronounced in central cities, which have reached a high level of urbanization, than in western cities where urbanization is progressing more slowly.
4.7. Spatial Spillover Effects
4.7.1. Selection of the Spatial Econometric Model
The NU process in cities exhibits spatial correlation effects due to the “strong linkages” of socio-economic factors. Therefore, spatial spillovers must be considered when assessing its impact on UER. Moran’s I values of the NU and UER indexes were significantly positive in most years, indicating a spatially positive correlation between NU and UER in each city. This supports the appropriateness of using a spatial econometric model in this study.
To determine the appropriate spatial econometric regression model, we conducted LM, LR, and Wald tests, with the results shown in
Table 11. Because the results of the LM, LR, and Wald tests were all significant, and the Hausman test results determined that a fixed-effects model was preferable to a random-effects model, we ultimately selected the two-way fixed-effects spatial Durbin model for this analysis.
4.7.2. Spatial Durbin Model Analysis
Table 12 presents the results of the benchmark regression examining the impact of NU on UER. To further emphasize the explanatory power of the two-way fixed-effects spatial Durbin model, we compared these results with those from the individual fixed-effects and time fixed-effects models. The spatial Durbin model with two-way fixed effects in column (3) had a higher R
2 value, a larger absolute value of the log-likelihood, and a better fit compared to the single fixed-effects models in columns (1) and (2). Therefore, we analyzed the regression results from the two-way fixed-effects spatial Durbin model.
Column (3) of
Table 12 shows that the regression coefficient for NU was significantly positive, indicating that the promotion of NU positively affected the UER of the cities involved, thereby further validating Hypothesis 1. Column (3) also presents the decomposition results of the spatial effects of NU on UER. The coefficients for the direct and indirect effects of NU on UER were 0.214 and 0.006, respectively, indicating that the promotion of NU in a city has a significant positive impact on its ecological resilience and a weak positive impact on the ecological resilience of neighboring cities. Hypothesis 6 was therefore verified.
5. Conclusions and Policy Recommendations
5.1. Conclusions
Based on panel data from 281 prefecture-level cities in China between 2000 and 2022, this study constructed an evaluation index system for NU and UER and employed the entropy weight TOPSIS comprehensive evaluation method to calculate the NU and UER comprehensive indices for each city over the period of 2000 to 2022. The mechanisms, heterogeneity, and spatial spillover effects of NU on UER were empirically investigated. The key findings were as follows. First, NU significantly improved overall UER, a conclusion that remained robust even after addressing endogeneity issues and conducting a series of robustness tests. Second, NU enhanced UER by optimizing the industrial structure and innovatively reallocating resources. Third, the impact of NU on UER varied across urban zones and resource endowments, with the effect being more pronounced in central and resource-oriented cities. Fourth, NU exhibited a spatial spillover effect on UER, with the direct effect outweighing the indirect effect. The findings highlight that NU significantly improved UER in resource-based and central cities, but the effect was not significant for non-resource-based, western and eastern cities. Notably, the study also uncovered that the promotion of NU in a city has a significant positive impact on its ecological resilience and a weak positive impact on the ecological resilience of neighboring cities.
These findings emphasize the need for differentiated policy approaches and targeted interventions. In terms of benefits, this research contributes to understanding how urban development and UER can be better integrated, offering new perspectives for urban ecological planning.
5.2. Policy Recommendations
The findings have several implications for enhancing UER while advancing the high-quality construction of NU. First, the development concept of NU should be reformulated to accelerate its progress, which can be achieved by fostering the comprehensive and coordinated development of population, economy, land, society, and space. The construction of NU must be closely aligned with the improvement of UER. To effectively construct NU there is a need for efficient and intensive land use, which can be achieved through the optimal allocation of land resources based on the actual demands for different land use types during social and economic transformation. At the same time, the principles of an ecological civilization and people-oriented development must be embedded throughout the entire construction of NU process. By integrating the enhancement of economic efficiency, the reduction in emissions, carbon sequestration, and the improvement of the ecological environment, the construction of NU should be advanced efficiently while simultaneously establishing a long-term mechanism to enhance ecological resilience.
Second, in recent years, as China’s economic development has entered a new phase, the country has transitioned from a period of rapid growth to a stage of high-quality development. The economy currently faces a complex situation marked by the convergence of three key developmental phases: a slowdown in growth, structural adjustment challenges, and the process of digesting the effects of previous stimulus policies. These overlapping factors have made traditional development unsustainable. Issues such as resource wastage and diminished resilience are becoming increasingly prominent, hindering high-quality economic development. In promoting the construction of NU, regions should more strongly support the optimization of innovative resource allocation and industrial structure to ensure the continuous improvement of UER. The government should actively provide policy and financial support for STRUCT. Local governments must consider the current situation and goals of urban development and introduce policies that guide the transformation and upgrading of traditional industries with high energy consumption and emissions. At the same time, regions should actively foster low-carbon, high-efficiency industries through tax reductions and subsidies, while considering both consumer demand and the city’s factor endowment.
Finally, cities should consider the spatial spillover effects from neighboring cities while taking into account their zones and resource endowments. They should formulate policies tailored to local conditions, based on a clear understanding of the stage of development and current status of the city’s NU. This will facilitate the efficient use of land resources and promote low-carbon transformation. Eastern and resource-oriented cities should accelerate the development of NU, making it a key strategy for enhancing the ecological resilience of these cities. For cities in central and western China, improving factor allocation capacity is crucial. This can be achieved by introducing skills development, technology, and advanced management practices from large cities, thereby better leveraging the impact of NU on UER.
However, this paper also has some limitations. On one hand, the academic community has not yet reached a consensus on the evaluation criteria and index system for NU. Due to data limitations, multi-dimensional processes, such as urban–rural integration, have not been included. On the other hand, the relationship between the two and the mechanisms underlying their interaction at a more detailed level have yet to be thoroughly explored. In the future, the indicator system can be further refined, and the scope of research can be expanded to provide more detailed guidance for better promoting the construction of NU and improving the overall ecological resilience of cities.