# Study on Coupling and Coordinated Development of Ecological Environment-Energy Consumption-Regional Economic Growth in Greater Bay Area around Hangzhou Bay

Authors: Yan Huo
Journal: Mathematical Problems in Engineering
 (2022)

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## Abstract

Environment, energy, and economy often constitute an interrelated and contradictory ternary system. In this study, Greater Bay Area around Hangzhou Bay Area is taken as the main research object, and Guangdong-Hong Kong-Macao Greater Bay Area is taken as the reference object. By constructing the index system of 3E system coordination evaluation model, the coordination degree and coordination status of ecological environment, energy consumption, and economic growth subsystems of the two areas are compared and analyzed, and the coupling relationship between 2E and 3E systems of Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area is further studied. The results show that the eco-environmental coordination degree and energy consumption coordination degree of the cities in Greater Bay Area around Hangzhou Bay are between 0.4248–0.5668 and 0.4528–0.5874, respectively, which are in the state of weak coordination to primary coordination, while the economic growth coordination degree is between 0.5022 and 0.6878, which is in the state of primary coordination to intermediate coordination. The coupling of 2E system in Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area shows linear growth and nonlinear growth, respectively (R2 = 0.997), presenting a good coupling development overall. The coupling levels of ecological environment-energy consumption, ecological environment-economic growth, and energy consumption-economic growth in Greater Bay Area around Hangzhou Bay increase by 18.94, 86.72, and 98.20% respectively. The coupling of 3E systems between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area presents a nonlinear development trend that is increasing year by year (R2 > 0.99), but the coupling level of 3E systems between the two is still low, both of which are in the primary/weak coordination state, while the overall growth rate of 3E system coupling in Greater Bay Area around Hangzhou Bay is higher than that of Guangdong-Hong Kong-Macao Greater Bay Area.


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## Body

## 1. Introduction

Since 1978, China’s economy has continued to grow rapidly, but the current situation of energy and environment with “high input,” “high pollution,” and “high-energy consumption” behind the economic growth has also caused severe energy shortage and environmental deterioration. Energy input, which mainly consists of coal, oil, and other primary energy sources, has made great contributions to the rapid economic growth, but at the same time, it has led to the deterioration of ecological environment and the poverty of resources, thus forming an interrelated and contradictory ternary system [1]. In recent years, as the concept of “sustainable development” has gradually taken shape, the three systems of energy, economy, and environment are closely linked. The coordination degree evaluation of environment, energy, and economy (3E coordination degree evaluation) is an evaluation method used to study and analyze the degree of interaction among many elements in the three subsystems, as well as the interaction between every two subsystems, and then comprehensively judge the coupling relationship among the three systems [2, 3].In the research of 3E system coordination degree evaluation, a large number of studies have studied the logical relationship between internal influencing factors and their related effects of 3E system from different perspectives [4]. In some studies, a large amount of data in time development order are taken as research samples, and the binary relationship between energy and environment, environment and economy, and energy and economy is analyzed by using relevant models and causality tests. In addition, a large number of studies have shown that there is a positive effect and two-way causal relationship between energy consumption and economic growth, and the energy-economy coupling relationship in different regions is quite different [5, 6]. In view of the coupling relationship between environment and energy system, the rapid production and consumption of energy will lead to a serious decline in environmental quality, and may also have negative effects on environmental economy. As for the coupling relationship between environment and economic system, some studies believe that environmental quality will degrade first and then improve with the improvement of economic development level, while the other studies think that there is a dynamic imbalance relationship between environmental quality and economic development level, and there are “U”-shaped and “N”-shaped correlations between them [7–9].Greater Bay Area around Hangzhou Bay is the second Greater Bay Area in China after Guangdong-Hong Kong-Macao Greater Bay Area. The Bay Area gathers Shanghai, Hangzhou, Ningbo, and other domestic first-tier and new first-tier cities. It not only has a good manufacturing base but also is an important city for China to participate in the global value chain division of labor [10]. At present, Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area have become an essential economic growth pole in China. Good industrial division of labor between the Greater Bay Area is conducive to further improving the quality of economic development. Based on this, this study takes Greater Bay Area around Hangzhou Bay as the main research object, and Guangdong-Hong Kong-Macao Greater Bay Area as the reference object. By constructing the index system of 3E system coordination evaluation model, this review compares and analyzes the coordination degree and coordination state of ecological environment, energy consumption, and economic growth subsystems in the two Greater Bay Area, and further studies and analyzes their coupling relationship of 2E and 3E systems, with a view to providing theoretical support for the future economic development of Greater Bay Area around Hangzhou Bay [11, 12].


## 2. Materials and Methods

Index System Establishment and Coupling Degree Solution [13–15]. (1) Index System Establishment of 3E System Coordination Evaluation Model. In order to compare the coordination degree of eco-environment, energy consumption, and regional economic growth systems between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area, the research sequence of this study is from 2008 to 2017. The research subjects are seven cities (Zhoushan, Ningbo, Shaoxing, Hangzhou, Huzhou, Jiaxing, and Shanghai) around Greater Bay Area of Hangzhou Bay and nine cities (Guangzhou, Shenzhen, Zhuhai, Foshan, Zhaoqing, Huizhou, Dongguan, Macao, and Hong Kong) in Guangdong-Hong Kong-Macao Greater Bay Area. The comprehensive evaluation of the coordination degree of ecological environment, energy consumption, and regional economic growth system (hereinafter referred to as the coordination degree of 3E system) is carried out on the basis of the evaluation of the three subsystems, including ecological environment, energy consumption, and economic growth. The coordination degree evaluation of the subsystems is mainly through the study on the quantifiable indexes of the coordination degree of the internal factors in each subsystem, thus reflecting the operation and development level of each subsystem. In this study, the 3E system coordination degree evaluation model index system is constructed by dividing the structure of each subsystem coordination evaluation index into three levels. The first level is the coordination degree index of each subsystem, and the second level is the classification index, including the total index, structure index, growth index, and benefit index, while the third level is the specific quantifiable index. The indexes of each level are shown in Table 1. Among them, there are eight evaluation indexes for the coordination degree of ecological environment system, seven evaluation indexes for the coordination degree of energy consumption system, and nine evaluation indexes for the coordination degree of economic growth system, totaling 24 indexes. The data of each index are from the Zhejiang Statistical Yearbook, the Shanghai Statistical Yearbook, and the Guangdong Statistical Yearbook in 2015.Table 1
Evaluation index system of coordination degree of ecological environment-energy consumption-regional economic growth system.
Coordination degreeTotal index C1Structure index C2Growth index C3Benefit index C4Coordination degree of ecological environmentProportion of ecological environment investment in GDPPer capita industrial waste gas emissions;Growth rate of environmental protection investment income;Removal rate of industrial waste gas;Per capita industrial wastewater discharge;Removal rate of industrial wastewater;Per capita output of industrial waste;Removal rate of industrial solid waste;Coordination degree of energy consumptionEnergy consumption per capita;Proportion of electric energy consumption to energy consumptionGDP growth rate brought by unit energy consumption;Total energy consumption accounts for the national proportion;Per capita electricity consumption;GDP growth rate brought by unit power consumption;Total electricity consumption accounts for the national proportion;Coordination degree of economic growthPer capita GDP;Proportion of output value of tertiary industry;GDP growth rate;GDP accounts for the national proportion;Per capita consumption level;Proportion of output value of secondary industryPer capita production growth rate;Total import and export volume accounts for the national proportion;Total import and export volume;(2) Numerical Standardization of Coordination Degree Evaluation of Each Subsystem in 3E System [16]. The weights of various indexes are mainly based on the different contributions of different indexes to the coordination degree of each subsystem, and the entropy method is used to determine the weight coefficient of classification index, including ecological environment coordination degree, energy consumption coordination degree, and economic growth coordination degree (the weight coefficients of each index are shown in Table 2). For indexes of different dimensions in different regions, the between-group range formula is used for standardization. For the positive index, the standardized value Uij  = (yij − ymin)/(ymax − ymin), for the negative index Uij  = (ymax − yij)/(ymax − ymin), where ymax, ymin, and yij are the maximum, minimum, and index values of each index data, respectively.Table 2
Weight value of coordination degree of each subsystem in 3E system.
Classification index weightTotal index weightStructure index weightGrowth index weightBenefit index weightCoordination degree of ecological environment0.250.150.250.35Coordination degree of energy consumption0.200.350.150.30Coordination degree of economic growth0.200.250.300.25(3) Calculation of Comprehensive Index and Coupling Degree of Each Subsystem in 3E System. The comprehensive index is used to evaluate and analyze the development level and status of environment, energy, and economy of each subsystem. The coupling value of 2E and 3E system is calculated by the following formula (1)–(3):(1)Xn=∑i=18PiUinn=1,2,3…9.(2)Yn=∑j=17PjUjnn=1,2,3…9.(3)Zn=∑k=19PkUknn=1,2,3…9.Among them, Xn, Yn, and Zn are the comprehensive indexes of ecological environment, energy consumption, and economic growth; Pi, Pj, and Pk are the weights of ecological environment, energy consumption, and economic growth; Uin, Ujn, and Ukn are the standardized values of each index.(4) Evaluation Criteria for Coupling Type of Coordination Degree of Each Subsystem in a 3E system [17]. The coordination degree of each index is between 0 and 1. The definition of coordination degree in this study is as follows: when the coordination degree is 1, the subsystem is in complete coordination state; when the coordination degree value is 0, the system is in a completely uncoordinated state; when the coordination degree value is in the interval of (0, 1), the evaluation criteria of coordination degree are shown in Table 3.Table 3
Evaluation criteria for coordination degree of each subsystem in 3E system.
Coordination value0–0.250.26–0.390.40–0.490.50–0.590.60–0.690.70–0.790.80–1.00Evaluation resultsVery uncoordinatedUncoordinatedWeakly coordinatedPrimary coordinatedIntermediate coordinatedStrongly coordinatedVery coordinated


## 3. Results

### 3.1. Evaluation and Comparison of the 3E System Coordination Degree between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area

#### 3.1.1. Evaluation of Coordination Degree of Regional Ecological Environment

The classification index evaluation results of regional ecological environment coordination degree in 2017 are shown in Table4. It can be seen from the table that the total index of regional ecological environment coordination degree in Greater Bay Area around Hangzhou Bay is between 0.1058 and 0.1421, and the growth index is between 0.2255 and 0.3741, which are both in a very uncoordinated state. The benefit index is between 0.2554 and 0.4854, which is in the transition from uncoordinated state to weakly coordinated state, while the structure index is between 0.8221 and 0.8874, which is in a very coordinated state. In contrast, the total index and benefit index of Guangdong-Hong Kong-Macao Greater Bay Area are lower, which are in a very uncoordinated state, but the growth index and structure index are higher, which are in an uncoordinated state and a very coordinated state, respectively. Figure 1 is a radar map of the ecological environment coordination degree of two Greater Bay Area cities. It can be seen from the map that the ecological environment coordination degree of each city gradually increases from 0.4248 to 0.5668 from Zhoushan city to Hangzhou Bay from south to north and develops from weak coordination state to primary coordination state. In contrast, the ecological environment coordination degree of Guangzhou and Shenzhen in Guangdong-Hong Kong-Macao Greater Bay Area has reached the primary coordination state, which is 0.5025 and 0.5081, respectively, while other cities are less than 0.49, which is in a weak coordination state. On the whole, the ecological environment coordination degree of the two Greater Bay Area cities is still in the transitional development stage from weak coordination to primary coordination, but the ecological environment coordination degree of the Greater Bay Area around Hangzhou Bay is higher, which also indicates that there is still much room for ecological environment optimization around Hangzhou Bay, and environmental pollution caused by the discharge of waste water, waste gas, and solid waste should be minimized [18].Table 4
Evaluation results of regional ecological environment coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.11250.88740.25210.4558Ningbo0.12140.87560.22550.4314Shaoxing0.11350.86450.26350.4101Hangzhou0.10580.89350.24450.4854Huzhou0.14210.82210.23170.4223Jiaxing0.11280.86130.26650.4187Shanghai0.12580.87890.37410.2554Guangzhou0.05510.92120.28450.1845Shenzhen0.04120.93220.32250.2059Zhuhai0.03640.85460.26450.1874Foshan0.08430.88410.28870.1854Zhaoqing0.09920.80310.21430.1423Huizhou0.03490.82140.24740.1521Dongguan0.05640.86690.27840.1885Macao0.04840.86470.26550.1745Hong Kong0.04670.84210.24570.1687Figure 1
Radar map of regional ecological environment coordination degree.


#### 3.1.2. Evaluation of Coordination Degree of Regional Energy Consumption

The evaluation results of coordination degree of regional energy consumption in 2017 are shown in Table5. It can be found that except Shanghai, the total index and benefit index of Greater Bay Area around Hangzhou Bay are between 0.40 and 0.49, which is in a weak coordination state, while Shanghai is as high as 0.9548 and 0.9032 respectively, which is in a very coordinated state. On the contrary, except Shanghai, the structure indexes of all cities are more than 0.8000, which is in a very coordinated state, while Shanghai is in a strongly coordinated state. In addition, the growth indexes of all cities are between 0.3154 and 0.4021, which is in an uncoordinated state and developed to a weak coordinated state. In contrast, the total index and growth index of all cities in Guangdong, Hong Kong, and Macao are between 0.30 and 0.49, which is in the transition from uncoordinated to weakly coordinated, while the benefit index and structure index are in the transition from primary coordination and intermediate coordination to strong coordination, respectively. Figure 2 shows the radar map of the coordination degree of energy consumption in the two areas. It can be seen that the coordination degree of energy consumption in the Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area is respectively between 0.4528–0.5874 and 0.4168–0.5903, which are in the state of weak coordination to primary coordination. With the development of energy technology, the energy utilization efficiency of the two Bay areas, which are located in the economically developed zone, is also improving, and the development of energy economy is in the stage of transformation and upgrading. However, it can be seen that the coordination degree of energy consumption in the two areas has not reached the intermediate and strong coordination state, indicating that there are still some energy consumption factors restricting the economic development [19].Table 5
Evaluation results of regional energy consumption coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.44260.92130.40210.4422Ningbo0.45230.88240.38120.4511Shaoxing0.42350.80310.33260.4125Hangzhou0.48520.90010.34270.4328Huzhou0.46520.81140.31540.4021Jiaxing0.42330.80310.30880.4116Shanghai0.95480.77650.32120.9032Guangzhou0.44210.88540.45520.5525Shenzhen0.42150.96510.46320.5614Zhuhai0.38540.82540.40580.5014Foshan0.32140.86120.44120.5101Zhaoqing0.33260.72130.45870.4564Huizhou0.36870.75210.33120.4554Dongguan0.39410.78980.32590.4987Macao0.35480.80210.40210.5217Figure 2
Radar map of regional energy consumption coordination degree.


#### 3.1.3. Evaluation of Coordination Degree of Regional Economic Growth

The evaluation results of the coordination degree of regional economic growth in 2017 are shown in Table6. It can be found that, except Shanghai, the total and growth indexes of regional economic growth in cities around the Hangzhou Bay are between 0.40 and 0.49, which is in a weak coordination state, while the structure index and the benefit index are between 0.50–0.59 and 0.60–0.69, respectively, which are in a primary and intermediate coordination state. The total index and benefit index of Shanghai are 0.8354 and 0.9978, respectively, which are in a very coordinated state, while the structure index and growth index are in an intermediate coordinated and uncoordinated state, respectively. In contrast, the coordination state of total index and benefit index in Guangdong-Hong Kong-Macao Greater Bay Area is better, which are in the intermediate coordination state, but the coordination state of growth index is weaker, which is in the uncoordinated state. Figure 3 shows the radar map of economic growth coordination degree of the two areas. It can be seen that the coordination degree of economic growth in Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area has reached the primary coordination state, but the average coordination degree of Guangdong-Hong Kong-Macao Greater Bay Area is higher. This is mainly because the two areas are located in the coastal economic zone, so the secondary and tertiary industries are developed, which obviously promotes regional economic growth. With the continuous upgrading and adjustment of China's industrial structure, the economic development of Greater Bay Area around Hangzhou Bay has gradually changed from the primary and secondary industries to the tertiary industry, which shows that the tertiary industry contributes more to the economy than the secondary industry. At the same time, the vigorous development of the tertiary industry can greatly reduce the ecological environment damage caused by energy consumption and play a positive role in promoting the development of ecological environment and energy.Table 6
Evaluation results of regional economic growth coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.41250.55240.44520.6754Ningbo0.43650.56320.48750.6998Shaoxing0.48870.51240.45320.6542Hangzhou0.48620.58360.49870.7014Huzhou0.45210.52130.42310.6374Jiaxing0.43650.53210.44510.6332Shanghai0.83540.65540.32560.9978Guangzhou0.68890.58410.32140.7528Shenzhen0.69210.59150.31450.7498Zhuhai0.62130.53210.36540.6548Foshan0.65530.54140.38540.6854Zhaoqing0.54650.48230.33210.5548Huizhou0.58980.49860.34780.5894Dongguan0.63250.53210.36890.6258Macao0.60210.52120.34580.6047Hong Kong0.61230.51240.37870.6123Figure 3
Radar map of regional economic growth coordination degree.


### 3.2. Coupling Correlation Analysis of 2E and 3E Systems between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area

#### 3.2.1. Coupling Analysis of 2E System

Since the changing trend of coupling level of ecological environment, energy consumption, and economic growth is closely related to the coupling of each 2E system, the correlation of each subsystem is further analyzed by comparing the coupling values of each 2E system and 3E system. Figure4 is a fitting curve of coupling situation of 2E and 3E systems between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area. It can be seen from the figure that the coupling of 2E systems in Greater Bay Area around Hangzhou Bay shows a linear growth trend during 2008–2017, and R2 of linear fitting is greater than 0.99, with a high degree of fitting. In contrast, the coupling of ecological environment–energy consumption in Guangdong-Hong Kong-Macao Greater Bay Area shows a linear development trend (R2 = 0.997), while the ecological environment–economic growth (R2 = 0.996) and energy consumption–economic growth (R2 = 0.992) show a nonlinear development trend. In the development of 2E system coupling situation, the coupling levels of ecological environment–energy consumption, ecological environment–economic growth and energy consumption–economic growth in the Greater Bay Area around Hangzhou Bay have increased from 0.475, 0.256, and 0.223 to 0.565, 0.478 and 0.442, with growth rates of 18.94, 86.72, and 98.20%, respectively. However, the coupling levels of ecological environment–energy consumption, ecological environment–economic growth, and energy consumption–economic growth in Guangdong-Hong Kong-Macao Greater Bay Area have increased from 0.532, 0.325, and 0.315 to 0.602, 0.557, and 0.562, respectively, with growth rates of 13.15, 71.38, and 70.15, respectively. This indicates that the 2E systems in two areas show a well-coupled development trend as a whole, in which the coupling changes of ecological environment–economic growth and energy consumption–economic growth are obvious, jumping from very uncoordinated state to weak coordinated state and uncoordinated state to intermediate coordinated state, respectively, while the coupling changes of ecological environment–energy consumption are relatively stable, only changing from weak coordination to primary coordination and primary coordination to intermediate coordination, but on the whole they tend to be coupled and optimized.Figure 4
2E and 3E system coupling situation fitting curves: (a) Greater Bay Area around Hangzhou Bay; (b) Guangdong-Hong Kong-Macao Greater Bay Area.
(a)(b)


#### 3.2.2. Coupling Analysis of 3E System

It can be seen from Figure4 that during 2008–2017, the coupling of 3E system between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area presents a nonlinear development trend (R2 > 0.99, with a high degree of fitting), but the coupling level of 3E system between the two areas is still low, both are in the primary/weak coordination state. The development state can be divided into two stages, the first stage is the slow growth stage from 2008 to 2012, in which the coupling level of 3E system is increased from 0.375 to 0.423 and 0.405 to 0.469, respectively; the second stage is the rapid growth stage from 2012 to 2017, and the coupling level of 3E system is increased from 0.423 to 0.525 and from 0.469 to 0.572, respectively. It can be seen that the coupling level of 3E system in the two areas has been improved absolutely, but the slope value of nonlinear fitting is small, which makes the overall change range insignificant, which may be mainly due to the decreasing trend of the comprehensive index of energy and environment. On the other hand, by comparing the coupling level of 3E system between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area, it can be found that the overall growth rate of 3E system coupling in Greater Bay Area around Hangzhou Bay is higher than that of Guangdong-Hong Kong-Macao Greater Bay Area, which is mainly due to the adjustment of economic structure and the transformation of ecological industry development mode under the guidance of “taking the lead in development strategy,” and the investment in energy use and ecological environment management is also strengthened. While the economy is growing rapidly, it also takes into account the protection of ecological environment and the development of new energy industry, so the 3E system presents a relatively benign development trend as a whole.Energy economy environment system is a complex system formed by the interaction and interaction among the three subsystems of energy, economy, and environment. Coordination between economic development and environmental protection is needed to achieve a win-win situation. Energy is a necessary factor of production for economic development, that is, one of the material bases, so economic growth is dependent on energy. On the other hand, economic growth can promote the large-scale development and utilization of energy. The development and utilization of energy will have a certain destructive effect on nature, and its waste will pollute the environment. Under the theoretical framework of low-carbon sustainable development, promoting high-quality economic development, efficient energy utilization, and high-level environmental protection is the only way to achieve sustainable development. Among them, high-quality economic development is the inevitable requirement of sustainable development, efficient energy utilization is the path choice of sustainable development, and high-level environmental protection is the goal of sustainable development.


## 3.1. Evaluation and Comparison of the 3E System Coordination Degree between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area

### 3.1.1. Evaluation of Coordination Degree of Regional Ecological Environment

The classification index evaluation results of regional ecological environment coordination degree in 2017 are shown in Table4. It can be seen from the table that the total index of regional ecological environment coordination degree in Greater Bay Area around Hangzhou Bay is between 0.1058 and 0.1421, and the growth index is between 0.2255 and 0.3741, which are both in a very uncoordinated state. The benefit index is between 0.2554 and 0.4854, which is in the transition from uncoordinated state to weakly coordinated state, while the structure index is between 0.8221 and 0.8874, which is in a very coordinated state. In contrast, the total index and benefit index of Guangdong-Hong Kong-Macao Greater Bay Area are lower, which are in a very uncoordinated state, but the growth index and structure index are higher, which are in an uncoordinated state and a very coordinated state, respectively. Figure 1 is a radar map of the ecological environment coordination degree of two Greater Bay Area cities. It can be seen from the map that the ecological environment coordination degree of each city gradually increases from 0.4248 to 0.5668 from Zhoushan city to Hangzhou Bay from south to north and develops from weak coordination state to primary coordination state. In contrast, the ecological environment coordination degree of Guangzhou and Shenzhen in Guangdong-Hong Kong-Macao Greater Bay Area has reached the primary coordination state, which is 0.5025 and 0.5081, respectively, while other cities are less than 0.49, which is in a weak coordination state. On the whole, the ecological environment coordination degree of the two Greater Bay Area cities is still in the transitional development stage from weak coordination to primary coordination, but the ecological environment coordination degree of the Greater Bay Area around Hangzhou Bay is higher, which also indicates that there is still much room for ecological environment optimization around Hangzhou Bay, and environmental pollution caused by the discharge of waste water, waste gas, and solid waste should be minimized [18].Table 4
Evaluation results of regional ecological environment coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.11250.88740.25210.4558Ningbo0.12140.87560.22550.4314Shaoxing0.11350.86450.26350.4101Hangzhou0.10580.89350.24450.4854Huzhou0.14210.82210.23170.4223Jiaxing0.11280.86130.26650.4187Shanghai0.12580.87890.37410.2554Guangzhou0.05510.92120.28450.1845Shenzhen0.04120.93220.32250.2059Zhuhai0.03640.85460.26450.1874Foshan0.08430.88410.28870.1854Zhaoqing0.09920.80310.21430.1423Huizhou0.03490.82140.24740.1521Dongguan0.05640.86690.27840.1885Macao0.04840.86470.26550.1745Hong Kong0.04670.84210.24570.1687Figure 1
Radar map of regional ecological environment coordination degree.


### 3.1.2. Evaluation of Coordination Degree of Regional Energy Consumption

The evaluation results of coordination degree of regional energy consumption in 2017 are shown in Table5. It can be found that except Shanghai, the total index and benefit index of Greater Bay Area around Hangzhou Bay are between 0.40 and 0.49, which is in a weak coordination state, while Shanghai is as high as 0.9548 and 0.9032 respectively, which is in a very coordinated state. On the contrary, except Shanghai, the structure indexes of all cities are more than 0.8000, which is in a very coordinated state, while Shanghai is in a strongly coordinated state. In addition, the growth indexes of all cities are between 0.3154 and 0.4021, which is in an uncoordinated state and developed to a weak coordinated state. In contrast, the total index and growth index of all cities in Guangdong, Hong Kong, and Macao are between 0.30 and 0.49, which is in the transition from uncoordinated to weakly coordinated, while the benefit index and structure index are in the transition from primary coordination and intermediate coordination to strong coordination, respectively. Figure 2 shows the radar map of the coordination degree of energy consumption in the two areas. It can be seen that the coordination degree of energy consumption in the Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area is respectively between 0.4528–0.5874 and 0.4168–0.5903, which are in the state of weak coordination to primary coordination. With the development of energy technology, the energy utilization efficiency of the two Bay areas, which are located in the economically developed zone, is also improving, and the development of energy economy is in the stage of transformation and upgrading. However, it can be seen that the coordination degree of energy consumption in the two areas has not reached the intermediate and strong coordination state, indicating that there are still some energy consumption factors restricting the economic development [19].Table 5
Evaluation results of regional energy consumption coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.44260.92130.40210.4422Ningbo0.45230.88240.38120.4511Shaoxing0.42350.80310.33260.4125Hangzhou0.48520.90010.34270.4328Huzhou0.46520.81140.31540.4021Jiaxing0.42330.80310.30880.4116Shanghai0.95480.77650.32120.9032Guangzhou0.44210.88540.45520.5525Shenzhen0.42150.96510.46320.5614Zhuhai0.38540.82540.40580.5014Foshan0.32140.86120.44120.5101Zhaoqing0.33260.72130.45870.4564Huizhou0.36870.75210.33120.4554Dongguan0.39410.78980.32590.4987Macao0.35480.80210.40210.5217Figure 2
Radar map of regional energy consumption coordination degree.


### 3.1.3. Evaluation of Coordination Degree of Regional Economic Growth

The evaluation results of the coordination degree of regional economic growth in 2017 are shown in Table6. It can be found that, except Shanghai, the total and growth indexes of regional economic growth in cities around the Hangzhou Bay are between 0.40 and 0.49, which is in a weak coordination state, while the structure index and the benefit index are between 0.50–0.59 and 0.60–0.69, respectively, which are in a primary and intermediate coordination state. The total index and benefit index of Shanghai are 0.8354 and 0.9978, respectively, which are in a very coordinated state, while the structure index and growth index are in an intermediate coordinated and uncoordinated state, respectively. In contrast, the coordination state of total index and benefit index in Guangdong-Hong Kong-Macao Greater Bay Area is better, which are in the intermediate coordination state, but the coordination state of growth index is weaker, which is in the uncoordinated state. Figure 3 shows the radar map of economic growth coordination degree of the two areas. It can be seen that the coordination degree of economic growth in Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area has reached the primary coordination state, but the average coordination degree of Guangdong-Hong Kong-Macao Greater Bay Area is higher. This is mainly because the two areas are located in the coastal economic zone, so the secondary and tertiary industries are developed, which obviously promotes regional economic growth. With the continuous upgrading and adjustment of China's industrial structure, the economic development of Greater Bay Area around Hangzhou Bay has gradually changed from the primary and secondary industries to the tertiary industry, which shows that the tertiary industry contributes more to the economy than the secondary industry. At the same time, the vigorous development of the tertiary industry can greatly reduce the ecological environment damage caused by energy consumption and play a positive role in promoting the development of ecological environment and energy.Table 6
Evaluation results of regional economic growth coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.41250.55240.44520.6754Ningbo0.43650.56320.48750.6998Shaoxing0.48870.51240.45320.6542Hangzhou0.48620.58360.49870.7014Huzhou0.45210.52130.42310.6374Jiaxing0.43650.53210.44510.6332Shanghai0.83540.65540.32560.9978Guangzhou0.68890.58410.32140.7528Shenzhen0.69210.59150.31450.7498Zhuhai0.62130.53210.36540.6548Foshan0.65530.54140.38540.6854Zhaoqing0.54650.48230.33210.5548Huizhou0.58980.49860.34780.5894Dongguan0.63250.53210.36890.6258Macao0.60210.52120.34580.6047Hong Kong0.61230.51240.37870.6123Figure 3
Radar map of regional economic growth coordination degree.


## 3.1.1. Evaluation of Coordination Degree of Regional Ecological Environment

The classification index evaluation results of regional ecological environment coordination degree in 2017 are shown in Table4. It can be seen from the table that the total index of regional ecological environment coordination degree in Greater Bay Area around Hangzhou Bay is between 0.1058 and 0.1421, and the growth index is between 0.2255 and 0.3741, which are both in a very uncoordinated state. The benefit index is between 0.2554 and 0.4854, which is in the transition from uncoordinated state to weakly coordinated state, while the structure index is between 0.8221 and 0.8874, which is in a very coordinated state. In contrast, the total index and benefit index of Guangdong-Hong Kong-Macao Greater Bay Area are lower, which are in a very uncoordinated state, but the growth index and structure index are higher, which are in an uncoordinated state and a very coordinated state, respectively. Figure 1 is a radar map of the ecological environment coordination degree of two Greater Bay Area cities. It can be seen from the map that the ecological environment coordination degree of each city gradually increases from 0.4248 to 0.5668 from Zhoushan city to Hangzhou Bay from south to north and develops from weak coordination state to primary coordination state. In contrast, the ecological environment coordination degree of Guangzhou and Shenzhen in Guangdong-Hong Kong-Macao Greater Bay Area has reached the primary coordination state, which is 0.5025 and 0.5081, respectively, while other cities are less than 0.49, which is in a weak coordination state. On the whole, the ecological environment coordination degree of the two Greater Bay Area cities is still in the transitional development stage from weak coordination to primary coordination, but the ecological environment coordination degree of the Greater Bay Area around Hangzhou Bay is higher, which also indicates that there is still much room for ecological environment optimization around Hangzhou Bay, and environmental pollution caused by the discharge of waste water, waste gas, and solid waste should be minimized [18].Table 4
Evaluation results of regional ecological environment coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.11250.88740.25210.4558Ningbo0.12140.87560.22550.4314Shaoxing0.11350.86450.26350.4101Hangzhou0.10580.89350.24450.4854Huzhou0.14210.82210.23170.4223Jiaxing0.11280.86130.26650.4187Shanghai0.12580.87890.37410.2554Guangzhou0.05510.92120.28450.1845Shenzhen0.04120.93220.32250.2059Zhuhai0.03640.85460.26450.1874Foshan0.08430.88410.28870.1854Zhaoqing0.09920.80310.21430.1423Huizhou0.03490.82140.24740.1521Dongguan0.05640.86690.27840.1885Macao0.04840.86470.26550.1745Hong Kong0.04670.84210.24570.1687Figure 1
Radar map of regional ecological environment coordination degree.


## 3.1.2. Evaluation of Coordination Degree of Regional Energy Consumption

The evaluation results of coordination degree of regional energy consumption in 2017 are shown in Table5. It can be found that except Shanghai, the total index and benefit index of Greater Bay Area around Hangzhou Bay are between 0.40 and 0.49, which is in a weak coordination state, while Shanghai is as high as 0.9548 and 0.9032 respectively, which is in a very coordinated state. On the contrary, except Shanghai, the structure indexes of all cities are more than 0.8000, which is in a very coordinated state, while Shanghai is in a strongly coordinated state. In addition, the growth indexes of all cities are between 0.3154 and 0.4021, which is in an uncoordinated state and developed to a weak coordinated state. In contrast, the total index and growth index of all cities in Guangdong, Hong Kong, and Macao are between 0.30 and 0.49, which is in the transition from uncoordinated to weakly coordinated, while the benefit index and structure index are in the transition from primary coordination and intermediate coordination to strong coordination, respectively. Figure 2 shows the radar map of the coordination degree of energy consumption in the two areas. It can be seen that the coordination degree of energy consumption in the Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area is respectively between 0.4528–0.5874 and 0.4168–0.5903, which are in the state of weak coordination to primary coordination. With the development of energy technology, the energy utilization efficiency of the two Bay areas, which are located in the economically developed zone, is also improving, and the development of energy economy is in the stage of transformation and upgrading. However, it can be seen that the coordination degree of energy consumption in the two areas has not reached the intermediate and strong coordination state, indicating that there are still some energy consumption factors restricting the economic development [19].Table 5
Evaluation results of regional energy consumption coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.44260.92130.40210.4422Ningbo0.45230.88240.38120.4511Shaoxing0.42350.80310.33260.4125Hangzhou0.48520.90010.34270.4328Huzhou0.46520.81140.31540.4021Jiaxing0.42330.80310.30880.4116Shanghai0.95480.77650.32120.9032Guangzhou0.44210.88540.45520.5525Shenzhen0.42150.96510.46320.5614Zhuhai0.38540.82540.40580.5014Foshan0.32140.86120.44120.5101Zhaoqing0.33260.72130.45870.4564Huizhou0.36870.75210.33120.4554Dongguan0.39410.78980.32590.4987Macao0.35480.80210.40210.5217Figure 2
Radar map of regional energy consumption coordination degree.


## 3.1.3. Evaluation of Coordination Degree of Regional Economic Growth

The evaluation results of the coordination degree of regional economic growth in 2017 are shown in Table6. It can be found that, except Shanghai, the total and growth indexes of regional economic growth in cities around the Hangzhou Bay are between 0.40 and 0.49, which is in a weak coordination state, while the structure index and the benefit index are between 0.50–0.59 and 0.60–0.69, respectively, which are in a primary and intermediate coordination state. The total index and benefit index of Shanghai are 0.8354 and 0.9978, respectively, which are in a very coordinated state, while the structure index and growth index are in an intermediate coordinated and uncoordinated state, respectively. In contrast, the coordination state of total index and benefit index in Guangdong-Hong Kong-Macao Greater Bay Area is better, which are in the intermediate coordination state, but the coordination state of growth index is weaker, which is in the uncoordinated state. Figure 3 shows the radar map of economic growth coordination degree of the two areas. It can be seen that the coordination degree of economic growth in Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area has reached the primary coordination state, but the average coordination degree of Guangdong-Hong Kong-Macao Greater Bay Area is higher. This is mainly because the two areas are located in the coastal economic zone, so the secondary and tertiary industries are developed, which obviously promotes regional economic growth. With the continuous upgrading and adjustment of China's industrial structure, the economic development of Greater Bay Area around Hangzhou Bay has gradually changed from the primary and secondary industries to the tertiary industry, which shows that the tertiary industry contributes more to the economy than the secondary industry. At the same time, the vigorous development of the tertiary industry can greatly reduce the ecological environment damage caused by energy consumption and play a positive role in promoting the development of ecological environment and energy.Table 6
Evaluation results of regional economic growth coordination degree in 2017.
AreaCoordination degree of total indexCoordination degree of structure indexCoordination degree of growth indexCoordination degree of benefit indexZhoushan0.41250.55240.44520.6754Ningbo0.43650.56320.48750.6998Shaoxing0.48870.51240.45320.6542Hangzhou0.48620.58360.49870.7014Huzhou0.45210.52130.42310.6374Jiaxing0.43650.53210.44510.6332Shanghai0.83540.65540.32560.9978Guangzhou0.68890.58410.32140.7528Shenzhen0.69210.59150.31450.7498Zhuhai0.62130.53210.36540.6548Foshan0.65530.54140.38540.6854Zhaoqing0.54650.48230.33210.5548Huizhou0.58980.49860.34780.5894Dongguan0.63250.53210.36890.6258Macao0.60210.52120.34580.6047Hong Kong0.61230.51240.37870.6123Figure 3
Radar map of regional economic growth coordination degree.


## 3.2. Coupling Correlation Analysis of 2E and 3E Systems between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area

### 3.2.1. Coupling Analysis of 2E System

Since the changing trend of coupling level of ecological environment, energy consumption, and economic growth is closely related to the coupling of each 2E system, the correlation of each subsystem is further analyzed by comparing the coupling values of each 2E system and 3E system. Figure4 is a fitting curve of coupling situation of 2E and 3E systems between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area. It can be seen from the figure that the coupling of 2E systems in Greater Bay Area around Hangzhou Bay shows a linear growth trend during 2008–2017, and R2 of linear fitting is greater than 0.99, with a high degree of fitting. In contrast, the coupling of ecological environment–energy consumption in Guangdong-Hong Kong-Macao Greater Bay Area shows a linear development trend (R2 = 0.997), while the ecological environment–economic growth (R2 = 0.996) and energy consumption–economic growth (R2 = 0.992) show a nonlinear development trend. In the development of 2E system coupling situation, the coupling levels of ecological environment–energy consumption, ecological environment–economic growth and energy consumption–economic growth in the Greater Bay Area around Hangzhou Bay have increased from 0.475, 0.256, and 0.223 to 0.565, 0.478 and 0.442, with growth rates of 18.94, 86.72, and 98.20%, respectively. However, the coupling levels of ecological environment–energy consumption, ecological environment–economic growth, and energy consumption–economic growth in Guangdong-Hong Kong-Macao Greater Bay Area have increased from 0.532, 0.325, and 0.315 to 0.602, 0.557, and 0.562, respectively, with growth rates of 13.15, 71.38, and 70.15, respectively. This indicates that the 2E systems in two areas show a well-coupled development trend as a whole, in which the coupling changes of ecological environment–economic growth and energy consumption–economic growth are obvious, jumping from very uncoordinated state to weak coordinated state and uncoordinated state to intermediate coordinated state, respectively, while the coupling changes of ecological environment–energy consumption are relatively stable, only changing from weak coordination to primary coordination and primary coordination to intermediate coordination, but on the whole they tend to be coupled and optimized.Figure 4
2E and 3E system coupling situation fitting curves: (a) Greater Bay Area around Hangzhou Bay; (b) Guangdong-Hong Kong-Macao Greater Bay Area.
(a)(b)


### 3.2.2. Coupling Analysis of 3E System

It can be seen from Figure4 that during 2008–2017, the coupling of 3E system between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area presents a nonlinear development trend (R2 > 0.99, with a high degree of fitting), but the coupling level of 3E system between the two areas is still low, both are in the primary/weak coordination state. The development state can be divided into two stages, the first stage is the slow growth stage from 2008 to 2012, in which the coupling level of 3E system is increased from 0.375 to 0.423 and 0.405 to 0.469, respectively; the second stage is the rapid growth stage from 2012 to 2017, and the coupling level of 3E system is increased from 0.423 to 0.525 and from 0.469 to 0.572, respectively. It can be seen that the coupling level of 3E system in the two areas has been improved absolutely, but the slope value of nonlinear fitting is small, which makes the overall change range insignificant, which may be mainly due to the decreasing trend of the comprehensive index of energy and environment. On the other hand, by comparing the coupling level of 3E system between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area, it can be found that the overall growth rate of 3E system coupling in Greater Bay Area around Hangzhou Bay is higher than that of Guangdong-Hong Kong-Macao Greater Bay Area, which is mainly due to the adjustment of economic structure and the transformation of ecological industry development mode under the guidance of “taking the lead in development strategy,” and the investment in energy use and ecological environment management is also strengthened. While the economy is growing rapidly, it also takes into account the protection of ecological environment and the development of new energy industry, so the 3E system presents a relatively benign development trend as a whole.Energy economy environment system is a complex system formed by the interaction and interaction among the three subsystems of energy, economy, and environment. Coordination between economic development and environmental protection is needed to achieve a win-win situation. Energy is a necessary factor of production for economic development, that is, one of the material bases, so economic growth is dependent on energy. On the other hand, economic growth can promote the large-scale development and utilization of energy. The development and utilization of energy will have a certain destructive effect on nature, and its waste will pollute the environment. Under the theoretical framework of low-carbon sustainable development, promoting high-quality economic development, efficient energy utilization, and high-level environmental protection is the only way to achieve sustainable development. Among them, high-quality economic development is the inevitable requirement of sustainable development, efficient energy utilization is the path choice of sustainable development, and high-level environmental protection is the goal of sustainable development.


## 3.2.1. Coupling Analysis of 2E System

Since the changing trend of coupling level of ecological environment, energy consumption, and economic growth is closely related to the coupling of each 2E system, the correlation of each subsystem is further analyzed by comparing the coupling values of each 2E system and 3E system. Figure4 is a fitting curve of coupling situation of 2E and 3E systems between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area. It can be seen from the figure that the coupling of 2E systems in Greater Bay Area around Hangzhou Bay shows a linear growth trend during 2008–2017, and R2 of linear fitting is greater than 0.99, with a high degree of fitting. In contrast, the coupling of ecological environment–energy consumption in Guangdong-Hong Kong-Macao Greater Bay Area shows a linear development trend (R2 = 0.997), while the ecological environment–economic growth (R2 = 0.996) and energy consumption–economic growth (R2 = 0.992) show a nonlinear development trend. In the development of 2E system coupling situation, the coupling levels of ecological environment–energy consumption, ecological environment–economic growth and energy consumption–economic growth in the Greater Bay Area around Hangzhou Bay have increased from 0.475, 0.256, and 0.223 to 0.565, 0.478 and 0.442, with growth rates of 18.94, 86.72, and 98.20%, respectively. However, the coupling levels of ecological environment–energy consumption, ecological environment–economic growth, and energy consumption–economic growth in Guangdong-Hong Kong-Macao Greater Bay Area have increased from 0.532, 0.325, and 0.315 to 0.602, 0.557, and 0.562, respectively, with growth rates of 13.15, 71.38, and 70.15, respectively. This indicates that the 2E systems in two areas show a well-coupled development trend as a whole, in which the coupling changes of ecological environment–economic growth and energy consumption–economic growth are obvious, jumping from very uncoordinated state to weak coordinated state and uncoordinated state to intermediate coordinated state, respectively, while the coupling changes of ecological environment–energy consumption are relatively stable, only changing from weak coordination to primary coordination and primary coordination to intermediate coordination, but on the whole they tend to be coupled and optimized.Figure 4
2E and 3E system coupling situation fitting curves: (a) Greater Bay Area around Hangzhou Bay; (b) Guangdong-Hong Kong-Macao Greater Bay Area.
(a)(b)


## 3.2.2. Coupling Analysis of 3E System

It can be seen from Figure4 that during 2008–2017, the coupling of 3E system between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area presents a nonlinear development trend (R2 > 0.99, with a high degree of fitting), but the coupling level of 3E system between the two areas is still low, both are in the primary/weak coordination state. The development state can be divided into two stages, the first stage is the slow growth stage from 2008 to 2012, in which the coupling level of 3E system is increased from 0.375 to 0.423 and 0.405 to 0.469, respectively; the second stage is the rapid growth stage from 2012 to 2017, and the coupling level of 3E system is increased from 0.423 to 0.525 and from 0.469 to 0.572, respectively. It can be seen that the coupling level of 3E system in the two areas has been improved absolutely, but the slope value of nonlinear fitting is small, which makes the overall change range insignificant, which may be mainly due to the decreasing trend of the comprehensive index of energy and environment. On the other hand, by comparing the coupling level of 3E system between Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area, it can be found that the overall growth rate of 3E system coupling in Greater Bay Area around Hangzhou Bay is higher than that of Guangdong-Hong Kong-Macao Greater Bay Area, which is mainly due to the adjustment of economic structure and the transformation of ecological industry development mode under the guidance of “taking the lead in development strategy,” and the investment in energy use and ecological environment management is also strengthened. While the economy is growing rapidly, it also takes into account the protection of ecological environment and the development of new energy industry, so the 3E system presents a relatively benign development trend as a whole.Energy economy environment system is a complex system formed by the interaction and interaction among the three subsystems of energy, economy, and environment. Coordination between economic development and environmental protection is needed to achieve a win-win situation. Energy is a necessary factor of production for economic development, that is, one of the material bases, so economic growth is dependent on energy. On the other hand, economic growth can promote the large-scale development and utilization of energy. The development and utilization of energy will have a certain destructive effect on nature, and its waste will pollute the environment. Under the theoretical framework of low-carbon sustainable development, promoting high-quality economic development, efficient energy utilization, and high-level environmental protection is the only way to achieve sustainable development. Among them, high-quality economic development is the inevitable requirement of sustainable development, efficient energy utilization is the path choice of sustainable development, and high-level environmental protection is the goal of sustainable development.


## 4. Conclusion

(1)
The evaluation results of 3E system coordination degree show that the ecological environment coordination degree of cities in Greater Bay Area around Hangzhou Bay is between 0.4248 and 0.5668, and the coordination degree of energy consumption is between 0.4528 and 0.5874, respectively, which are in the development state from weak coordination to primary coordination, while the coordination degree of economic growth is between 0.5022 and 0.6878, which is in the development state from primary coordination to intermediate coordination.(2)
The results of 2E system coupling analysis show that the 2E system coupling of Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area presents linear growth and nonlinear growth, respectively (R2 = 0.997), showing a good coupling development trend on the whole. The coupling levels of ecological environment–energy consumption, ecological environment–economic growth, and energy consumption–economic growth in Greater Bay Area around Hangzhou Bay increase by 18.94, 86.72, and 98.20%, respectively, while those of Guangdong-Hong Kong-Macao Greater Bay Area increase by 13.15, 71.38, and 70.15%, respectively.(3)
The results of 3E system coupling analysis show that the 3E system coupling of Greater Bay Area around Hangzhou Bay and Guangdong-Hong Kong-Macao Greater Bay Area presents a nonlinear development trend that is increasing (R2 > 0.99) year by year. The 3 E system coupling level of the two areas is still low both in the primary/weak coordination state, but the overall growth rate of 3E system coupling of Greater Bay Area around Hangzhou Bay is higher than that of Guangdong-Hong Kong-Macao Greater Bay Area.



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*Source: 7738240-2022-05-20.xml*