On 20 October 2021, the Central Committee of the Communist Party of China and the State Council issued the “Outline of the Construction Plan for the Chengdu-Chongqing Economic Circle “. This outline is to build the “fourth pole” to support national economic growth and to provide a strong power source for high-quality development in western China. The construction of the Chengdu-Chongqing Economic Circle has been escalated to a national strategy that aims to turn the Chengdu-Chongqing area into an economic circle with its strengths, and form a distinctive, reasonable layout, and an efficient urban agglomeration development pattern [
1]. Therefore, the scale of cities has expanded rapidly, and the functions of cities and urban agglomerations have become more complex than before. Coupled with the combined impacts of rising temperatures, world changes and the COVID-19 pandemic, the economic, social, ecological, infrastructure and cultural construction of the Chengdu-Chongqing economic circle are potentially threatened [
2]. Therefore, it is of great significance for cities and urban agglomerations to take measures to mitigate disturbances, and prevent and resolve urban risks.
Improving the level of urban resilience requires to understand a series of basic issues of urban resilience, such as conceptual evolution, evaluation framework, research methods, and influencing factors. Resilience comes from the Latin word resilire; meaning to spring back [
6]. The cognition of resilience has gone through three stages, namely engineering resilience, ecological resilience, and evolutionary resilience. Engineering resilience regards resilience as the ability to return to its original state after being subjected to external forces, which is the restoration of the initial homeostasis [
7]. Ecological resilience was first proposed by Canadian ecologist Holling [
8]. He emphasizes resilience as the ability of an ecosystem to absorb change, sustain and restore equilibrium [
9], thereby shaping a new homeostasis. In the 1990s, the concept of evolutionary resilience emerged, which considered resilience as a dynamic system property with adaptability, learning ability and innovation [
5]. Evolutionary resilience is the ability of complex social-ecological systems to adapt and change in response to stress and constraints [
10]. Under the framework of evolutionary resilience, the urban resilience assessment system has attracted the attention of many scholars and has become one of the most important contents of urban resilience research. For example, CUTTER constructs a total of 49 indicators in six dimensions including social, economic, institutional, infrastructure, ecological and social functions to explore the improvement effect and spatial pattern distribution of urban resilience in the United States [
11]. Jha believes that urban resilience should be decomposed into infrastructure, economic, social, and institutional dimensions [
12]. Joerin finds that urban spatial planning in developing countries less reflects the attitudes of the community public [
13]. He defines community resilience by dividing it into 125 variables in five dimensions: infrastructure, society, economy, institutions and nature [
13]. Liu measured the resilience system of 288 cities in China by constructing the City Resilience Development Index (CRDI) framework from five thematic layers: cultural, economic, social, environmental, and image [
14]. Paulo considers urban resilience as a complex system consisting of natural, economic, social, physical, and institutional components of cities [
15]. Shi et al. constructs a system of indicators covering economic, social, and engineering dimensions to evaluate the resilience of urban networks [
16]. Zheng, Yan, et al. constructs an urban resilience index system in four dimensions: economic, social, ecological and infrastructural [
17]. Zhu and Sun measure the urban resilience in the three major urban agglomerations in China with 25 indicators from four dimensions of ecology, economy, society and engineering with 25 indicators [
18]. Liu et al. analyze four levels of economic resilience, social resilience, ecological resilience, and infrastructural resilience on the spatial pattern of urban resilience and its influencing factors in Henan Province of China [
19]. It can be concluded from the above literature that there is no fully unified resilience assessment system currently. Social resilience and economic resilience are the dimensions that scholars prefer to choose, which reflects the unity of constructing evaluation frameworks. However, the selection of other dimensions and indicators is based on the location, resources, and development stages of the research objects. Scholars tend to adopt the method of classification and evaluation, thus showing obvious differentiated characteristics [
20]. It is precise because the urban resilience’s background conditions, and the disturbances and shocks it faces are different, and the regular relationships among the main variables that affect or determine the level of urban resilience are also different. At present, scholars mainly focus on the influence of administrative power, openness, innovation, etc. [
19], and rarely involve the influence of culture. The established literature mainly uses the spatial panel econometric model and panel regression analysis to study the factors influencing urban resilience, staying on the mono- or binary analysis of causality [
18]. The existing literature mainly analyzes the driving effect of a single variable on urban resilience, emphasizing the independent net effect of each variable [
21]. A city is a giant system closely linked by multiple elements and systems such as space, industry, population, environment and culture. The various elements and systems in the city are interdependent, and influence and interact with each other. The prosperity or decline of cities and urban agglomerations are the results of a combination of factors, rather than the independent effects of an individual factor. Therefore, we cannot just stop at the analysis of a single influencing factor. Instead, we should start from an overall perspective innovatively. This paper adopts a holistic and configurational approach to explain the impact and mechanism of influencing factors and their combinations on urban resilience and the overall resilience of urban agglomerations.
Building resilient cities and improving the resilience level of urban agglomeration are an important part of the Chengdu-Chongqing economic circle to achieve high-quality development. We need to measure and evaluate the resilience levels of cities in the domain and analyze the key influencing factors and combinations. In comparison with other urban resilience studies, our contribution is to propose a new urban resilience framework for measuring the level of urban resilience. We add cultural dimension on the basis of general research, which is under the fully considerations the strategic position, resource conditions, historical origin, cultural heritage and characteristics of urban construction of the Chengdu-Chongqing economic circle. There are differences between the overall construction of the Chengdu-Chongqing economic circle and the construction of single city, and the key elements suitable for the overall development may not be suitable for the development of each city. Therefore, we innovatively adopt the qualitative comparative analysis method of fuzzy sets to analyze the nonlinear interaction from various variables, and accurately reflect the key factors affecting the improvement of urban resilience through the configuration effect. Our contribution lies in the analysis of urban agglomerations, regions and intra-regional cities. We try our best to avoid the contradiction between urban agglomeration construction and intra-regional city construction and find the best way to improve the resilience for both.
In summary, firstly, we use the entropy-weighted-TOPSIS comprehensive evaluation method (Technique for Order Preference by Similarity to Ideal Solution) to measure the urban resilience level of 44 cities in the Chengdu-Chongqing economic circle in five dimensions: economic, social, ecological, infrastructure and cultural. Secondly, we employ the urban resilience level as the outcome variable; political, market, financial, openness, innovation and cultural forces as the condition variables. We also utilize the fuzzy-set Qualitative Comparative Analysis (fsQCA) to find out the relationship between the factor configurations and the outcome, and to investigate the factors that generate high (or low) urban resilience level. (or low) levels of urban resilience. At last, under the guidance of the core driving force, we propose an optimum path for the urban development overall, regional and intra-regional levels, which can synergistically promote the improvement of the overall resilience level of cities and urban agglomerations. In future, achieve high-quality and sustainable development of the Chengdu-Chongqing economic circle.