1. Introduction
Urbanization is a critical path for the rapid development of a country. China has entered the stage of building a moderately prosperous society in all aspects and is currently in an important stage of economic transformation, upgrading, and further promotion of socialist modernization, which is also a critical period for the in-depth development of urbanization construction. Since China released the National New Urbanization Plan 2014–2020 in 2014, new urbanization projects have become key in all regions. The traditional definition of urbanization simply refers to the process of a rural population transforming into an urban population. New-type urbanization takes urban–rural integration, industrial interaction, conservation and intensification, ecological livability, and harmonious development as its basic characteristics, and the coordinated development and mutual promotion of large, medium, and small cities, towns, and new rural communities is its goal. As the connotation of new urbanization continues to deepen, in 2020, the Fifth Plenary Session of the 19th Central Committee of the Communist Party of China proposed to promote a new type of urbanization with people at its core, build a new pattern of territorial space development and protection, and promote the coordinated development of the region. The Yellow River Basin has been an important birthplace of civilization in China since ancient times. It is also an important object of China’s policy of arranging industrialization and modernization, so the promotion and high-quality development of new urbanization in the region has been of great concern. According to a research report released by the Development Research Center of the State Council, the urbanization of the Yellow River Basin is now in the middle and late stages of rapid development. It is necessary to change the way of planning based on “population growth”; accelerate the application and promotion of ecological technology, new energy, and digital technology in the Yellow River Basin; promote the change in production and lifestyle in the whole basin; and reduce the impact of urbanization on the population. The government work report of the 13th National People’s Congress proposes to solidly promote environmental protection and high-quality development in the Yellow River Basin and to deeply promote a new urbanization strategy with people at its core. Therefore, new urbanization in the Yellow River Basin should move from the original criteria of population number growth to the direction of high-quality development, such as people-centered development and green development.
The Yellow River Basin is an important ecological barrier and economic zone in China and a major material production area for resources and food in China. The high-quality development and ecological protection of the Yellow River Basin are major national strategies, along with the coordinated development of the Beijing–Tianjin wing, the development of the Yangtze River Economic Belt, the construction of the Guangdong–Hong Kong–Macao Bay Area, and the integration of the Yangtze River Delta. The Yellow River Basin has been a disaster-prone area since ancient times, but now, under the economic construction of the country, the occurrence of disasters has been greatly reduced. However, with the new urbanization of economic construction activities, there are still ecological and environmental problems. For example, in 2019, the central inspection team found that enterprises do not follow the plan of mining in Gansu Province; there are abandoned slag piles, wastewater discharge, and other pollution problems, all of which are more serious than before. The progress of remediation work is slow, and the environmental risks are high. In this context, it is of great practical significance to study the coupling and coordination between new urbanization and ecological resources and the environment in the Yellow River Basin.
Based on this background, this paper constructs a new urbanization evaluation index system from the perspective of the human core. The single element carrying capacity combined with the total carrying capacity is used to measure the regional ecological, resource, and environmental levels. The evaluation index system of ecological carrying capacity is reconstructed to measure cities’ new urbanization and ecological carrying capacity levels in the Yellow River Basin. The uncoordinated coupling degree model is used to measure the uncoordinated coupling degree between the new urbanization and ecological carrying capacity of the Yellow River Basin. The problems of the coordinated development of the new urbanization and ecological carrying capacity of the Yellow River Basin are analyzed from the perspective of reverse thinking. Suggestions are made to promote the coordinated development of the new urbanization and ecological carrying capacity of the Yellow River Basin.
At present, there have been a large number of studies on the coupling and coordination between new urbanization and the ecological environment system. This paper summarizes two aspects: constructing an index system of new urbanization and ecological carrying capacity. Due to the different definition categories of new urbanization and ecological carrying capacity, scholars have not formed a unified and standard system for constructing indicator systems of the two systems. In terms of new urbanization, most scholars construct indicator systems around four aspects, population, economy, society, and space, but there are some differences in selecting specific indicators. For example, Zhang and Jiao [
1] decomposed the urbanization system into four subsystems of population urbanization, economic urbanization, spatial urbanization, and social urbanization from the perspective of inter-provincial urbanization and selected the corresponding indicators. The conclusion was that the coupling and coordination degree of inter-provincial urbanization and the ecological environment system in China showed an increasing trend. Tan et al. [
2] concluded that the spatial concentration of population and employment structure transformation in the process of population urbanization are often closely linked with urban spatial expansion, so the population and spatial urbanization process is reflected by the population urbanization index system. It was concluded that the coupling coordination degree of urbanization and ecological environment in Jilin Province showed a continuous growth trend and developed from basic incoordination to advanced coordination. Zhang et al. [
3] constructed a triangular model of urbanization quality based on the efficiency-level model and divided it into two subsystem indicators of urbanization level and urbanization efficiency. They concluded that the distribution of the coupling degree of new urbanization quality and ecological environment carrying capacity in Chongqing city and counties is basically in line with the spatial differentiation rule of “one circle and two wings”. Wu [
4] combined the development status of each district and city in Fujian Province and constructed the urbanization index system from five aspects, namely population, economic, infrastructure, social, innovation, and globalization factors. It was concluded that the coordinated development between urbanization and the resource and environmental carrying capacity of Fujian Province has been improving. Zhao et al. [
5] drew on the existing results to construct a new urbanization level system from the perspectives of three subsystems: the urbanization level, public service level, and infrastructure level. In terms of ecological carrying capacity, Xiong et al. [
6] constructed the ecological carrying capacity of the Dongting Lake area from three perspectives: the support capacity of the ecological resilience subsystem, the capacity of the resource environment subsystem, and the development capacity of the socio-economic subsystem. The spatial pattern of ecological carrying capacity of the Dongting Lake area from southwest to northeast is generally a “W” shape (higher–lower), with significant county differences in the inverted “U” shape. Shen et al. [
7] used the state–space method to construct the ecological carrying capacity index system from three aspects, social coordination, resource and environmental support, and ecological resilience, and analyzed the spatial and temporal patterns of the middle reaches of the Yangtze River urban agglomeration, and the overall ecological carrying capacity index showed a fluctuating, upward “W” type trend. Zhang and Shi [
8] used the ecological footprint model to construct the ecological carrying capacity system by selecting biological resources and energy resources data, and the results showed the ecological footprint per capita of the middle reaches of the Yangtze River urban agglomeration as a whole and Hubei, Hunan, and Jiangxi provinces showed “inverted U-shaped” characteristics. Feng et al. [
9] used the biological abundance index and the ecological potential index of arable land to construct an evaluation system from three perspectives: the support capacity of the ecological resilience subsystem, the capacity of the resource and environment subsystem, and the development pressure of the socio-economic subsystem. Zhang et al. [
10] used the pressure–state–potential (PSP) conceptual model with the help of GIS technology to construct the index systems of ecological pressure, ecological carrying state, and ecological carrying potential and obtained the conclusion that the spatial pattern of ecological carrying capacity suitability of sub-elements in the coastal region of Jiangsu showed various trends, and the same index had significant differences in magnitude, area, proportion, and layout in different cities and counties. Li et al. [
11] used the pressure–state–response (PSR) model to select indicators in terms of forest support, social pressure, and system response, and the results showed that the overall forest ecological carrying capacity condition in Anhui Province has been greatly improved and most of the districts and counties in the province are at the loadable level.
Another aspect is the study of the coupling relationship between new urbanization and the ecological environment. The idea of coordination between urbanization, resources, and the environment can be traced back to the Socratic era when people began to pay attention to the relationship between people and the environment [
12]. The early urban planning ideas in the West incorporated natural environmental factors into the overall planning of towns and cities, which is considered the germ of the coordination between urbanization, resources, and the environment [
13]. Since modern times, the locational theory represented by Hettner and Hartshorne has been gradually introduced, and the idea of promoting the harmonious development of towns, resources, and the environment has been further developed [
14]. Subsequently, Howard’s idyllic city theory was born, and the study of green urbanization entered a new stage, the core of which is still the harmonious development of towns and the environment [
15]. Inspired by the idyllic city theory, the ecological concept reflected in the urbanization process has gradually developed toward systematization and standardization. Between the 1960s and 1970s, foreign scholars used various methods and models to study the relationship between urbanization and the ecological environment empirically. The existence of the “environmental Kuznets inverted U-shaped curve (EKC)” has become a research component of coordinated environmental and economic development [
16,
17,
18]. In an in-depth study of the correlation between environment and urban development, some scholars [
19,
20,
21,
22,
23,
24] have used system dynamics (SD) models and Granger causality tests, as well as comprehensive evaluation models. In terms of the urban evaluation system, most scholars mainly construct urban evaluation index systems from demographic, economic, social, and spatial aspects and establish a pressure–state–response (PSR) model of resources and environment. In addition, some scholars [
25,
26] have integrated the concept of green objectives of new urbanization into resources and the environment and established a system model for the sustainable and coordinated development of population, resources, ecology, and the environment. Bi et al. [
27] constructed an environment–economy coordination coefficient model based on the sustainable development system. In addition, some scholars [
28] have established a model of the level of coupled collaborative development under a complex economic and environmental system based on mathematical operations. Yang [
29] used the coupled coordinated development model of towns and ecosystems to classify the coordinated development level based on ecological theory. Some other scholars [
30,
31] have used the coordinated development model to study the coupling of economic urbanization and the environment in coastal areas. Most other studies [
32,
33,
34] have explored the level of coordinated development between urbanization, resources, and the environment from the perspective of cities. In recent years, scholars have started to analyze the non-coordinated coupling degree between new urbanization and the ecological environment from the perspective of reverse thinking. At present, there have been fewer studies on the non-coordinated coupling between systems, and the so-called non-coordinated coupling refers to the development mechanism of urbanization and ecological environment to produce non-benign interactions. Spatio-temporal factors function with a coupling relationship between new urbanization and ecological environment, containing a variety of coordinated and non-coordinated coupling states, so some scholars analyze the new urbanization and ecological environment system based on reverse thinking. Furthermore, the problem can be diagnosed by analyzing non-coordinated pathology, which is of guiding significance for new urbanization and ecological environment leading to coordinated development. Sun [
35] analyzed the coordinated development of urbanization and ecological environment in Jiangsu Province from the perspective of analytical pathology by using the non-coordinated coupling model thinking and obtained the conclusion that the non-coordinated coupling degree of urbanization and ecological environment in Jiangsu Province is continuously decreasing but always stays in the stage of grinding non-coordinated coupling. By analyzing the non-coordinated coupling relationship between urbanization and ecological environment in Shandong Province, Ren [
36] combined spatial analysis methods to diagnose the influencing factors of their non-coordinated coupling characteristics and obtained the conclusion that the level of urbanization, ecological environment, and their non-coordinated coupling degree in Shandong Province showed a spatial pattern of superiority of the Ludong and Luzhong regions over western regions. Liang and Chen [
37] argued that the development mechanism of urbanization and ecological environment produces non-benign interaction, which is a problem of regional economic development with a certain inevitability.
Synthesizing previous studies, we find that there is room for further expansion of research. First, the index system of new urbanization and ecological environment in the Yellow River Basin is intricate, but the existing index system cannot completely reflect the connotation of new urbanization and the complexity of the ecological environment. Most scholars construct the new urbanization index system from the perspectives of population, economy, and space. The development status of the Yellow River Basin now is different from that in the past, and it is impossible to quantify new urbanization with people as the core and to take into account high-quality development with past methods. Scholars have used different ways to quantify ecological carrying capacities, such as the comprehensive evaluation method, the ecological footprint method, the state–space method, and the pressure–state–response (PSR) model. However, the ecological environment itself has complex and diverse characteristics. For example, the evaluation of water resources by comprehensive evaluation only considers surface water resources but not groundwater resources; the ecological footprint method measures the consumption of resources by paying attention to direct consumption but not indirect consumption, ignoring other influencing factors in resource utilization. This work argues that using only a single method cannot show the complex situation of the regional ecological environment in detail. This paper adds the subsystems of the public management level and the science and technology input level to the index system of new urbanization based on previous research. The public management level reflects the perfect degree of the social management mechanism, and the science and technology input shows the development level of regional high-tech industry. The social management mechanism determines the lower limit of the happiness of residents’ lives, while the science and technology input determines the upper limit of human living standards. Therefore, adding the subsystems of the public management level and the science and technology input levels to the index system can more accurately measure the high-quality development level of new urbanization. For the ecological environment, this work selects indicators from the concept of ecological carrying capacity and five perspectives: resource utilization, energy consumption, government regulation and control, ecological pressure, and ecological elasticity.
In this paper, the resource utilization and government regulation subsystems are added based on a previous study. This paper measures the water resources carrying capacity indicators by referring to the water resources carrying capacity measurement method based on the water footprint theory by Huang et al. [
38] and measures the spatial bearing capacity index of construction by referring to the measurement method in the “Territorial Resources and Environmental Carrying Capacity Evaluation Serving the Preparation of Territorial Planning” issued by the Ministry of Land and Resources. The per capita sown area of food crops represents agricultural land resources, and the per capita local financial expenditure on agriculture, forestry, and water affairs index represents the restoration power of soil and water resources, which not only quantifies urban soil and water resources in a more detailed way but also adds the dynamic influence of the human restoration of soil and water resources, and can measure the resource utilization in the process of new urbanization more accurately. In the new urbanization process, ecological and environmental protection engineering plays an important role, so this paper adds the government regulation subsystem to represent the execution power of government ecological and environmental engineering. Second, there are few domestic and foreign studies on the non-coordinated coupling of new urbanization and ecological environment, and domestic studies on the non-coordinated coupling of new urbanization and ecological carrying capacity have not yet appeared. Moreover, most of the existing domestic research of non-coordinated coupling is calculated based on the coupled coordination model. The results of the coupled coordination model mainly consider the horizontal spatial differences in the research object and do not take into account the vertical influence of the research object in time. This paper refers to the method of Wang et al. [
39]. It improves the non-coordinated coupling model by adding time adjustment coefficients to the operation so that the model joins the adjustment of the interaction effect in time, which takes into account the system’s internal dynamics in time effects and brings the results closer to the actual situation.