The Evolutionary Path of the Center of Gravity for Water Use, the Population, and the Economy, and Their Decomposed Contributions in China from 1965 to 2019

Abstract

Sustainable development is a hot issue in global research today. As a large developing country, China has increasingly prominent conflicts between water use, the population, and the economy, so it is necessary to solve the sustainable development issues represented by water use, the population, and the economy. To explore the evolutionary process for water use, the population, and the economy in China, we calculated the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019 by using the center of gravity model, and we calculated the decomposed contributions of the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019, which the six major areas in China contributed to, by using the center of gravity decomposed contributions model. The results show the following: (1) As a whole, the center of gravity cumulative yearly moving distance for water use was 835.77 km, and the center of gravity moving direction as well as angle were north by east, 18.95°. The center of gravity cumulative yearly moving distance for the population was 113.40 km, and the center of gravity moving direction as well as angle were south by west, 31.50°. The center of gravity cumulative yearly moving distance for the economy was 449.83 km, and the center of gravity moving direction as well as angle were south by east, 8.63°. (2) From the decomposed value contribution rate of the evolutionary path of the center of gravity in the latitude direction for water use, the population, and the economy in China from 1965 to 2019, which the six major areas in China contributed to, Northeast China contributed the most (42.26%, 34.09%, and 39.37%, respectively). The increasing proportion of total water use consumption in Northeast China most positively affected the evolutionary path of the center of gravity for water use in China, moving northwards from 1965 to 2019, and the decreasing proportion of the total population as well as gross regional product in Northeast China most negatively affected the evolutionary path of the center of gravity for the population and economy in China, moving southwards from 1965 to 2019.

1. Introduction

Water is a basic natural resource [1] and a strategic economic resource [2] on which humans depend for survival and development, being vital to the sustainable development of the population and economic society [3]. With the rapid increase in the population and the rapid development of economic society under the influences of climate change [4], urbanization [5], and other factors, the contradiction between water resource supply and demand is gradually worsening [6]. As such, the rational use and management of water resources pose serious challenges [7]. The limited nature of water resources is imposing strict constraints on the population and economic development [8], thus affecting living standards and hindering the high-quality development of economic society [9]. Especially in recent years, the conflict between water use, the population, and the economy has worsened, and so appropriate measures need to be implemented [10]. Therefore, the evolutionary process of the three must be explored in order to devise suitable solutions.

Many scholars at home and abroad have conducted in-depth research on this issue. Mumbi et al. [11] investigated water demand, water use pattern changes, and water scarcity in terms of Nile transboundary water resources through comparing the situations in Egypt and Kenya. Wang et al. [12] proposed an improved water resources ecological footprint model and obtained more accurate water resource consumption as well as supply results. McDonald [13] investigated the population loss of 13 major central cities in the American manufacturing belt from 1950 to 2020. Ma et al. [14] constructed a population–land–industry indicator system to analyze the degree of coupling and mutual feedback among their urbanization. Xi et al. [15] studied the influence of the crude oil trade pattern change on GDP along the “One Belt One Road” countries based on complex network and econometric theory. Chen et al. [16] analyzed the impact of CO₂ emissions at the national and provincial levels on the Chinese economy from 1997 to 2019 in terms of historical patterns and current drivers. Other scholars have conducted similar studies [17,18,19,20].

Most previous researchers have analyzed the evolutionary process for water use, the population, and the economy through traditional mathematical modeling, but studies considering the spatial scale are scarce. The center of gravity model can be used to analyze the spatial distribution characteristics of a study object and its evolution. Zhang et al. [21] empirically studied the spatial distribution of the population, the economy, and water resources in Northeast China via the use of geometric center of gravity and grey correlation models. Grether et al. [22] proposed a novel and simple world economy center of gravity measuring standard. Yan et al. [23] used the Kriging, spatial autocorrelation, and center of gravity methods to analyze daily air quality index (AQI) data in China from 2015 to 2020. Based on the center of gravity model, we can also use standard deviation ellipses [24], geographic probes [25], and other spatial scale methods. The research on the spatial center of gravity model is relatively mature, with study objects at the global [26], national [27], provincial administrative area [28], urban agglomeration [29], and river basin [30] levels; however, the center of gravity model has rarely been applied on a multiyear time scale, especially from the perspective of a whole country.

China is a developing country experiencing rapid economic and social development; however, the regional gaps in development are becoming increasingly prominent, and the constraint caused by water resources is further increasing the differences in economic growth among areas in China. Therefore, the evolutionary process for water use, the population, and the economy in China must be studied on a multiyear time scale via the use of the center of gravity model.

This paper uses the center of gravity model and the center of gravity decomposed contributions model to solve the sustainable development issue represented by water use, the population, and the economy in China. The center of gravity model was used to calculate the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019. The center of gravity decomposed contributions model was used to calculate the decomposed contributions of the evolutionary path of the center of gravity for water use, the population, and the economy in China, which the six major areas in China contributed to from 1965 to 2019.

The rest of this paper is organized as follows: In Section 2 we report the data sources. In Section 3 we introduce the study methods, including the center of gravity model and the center of gravity decomposed contributions model. In Section 4 we describe the study results, including the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019 in addition to the decomposed contributions of the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019. In Section 5 we discuss the study results, including a comparison of the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019 as well as a comparison of the decomposed contributions of the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019, which the six major areas in China contributed to. Section 6 we outline the study conclusions and future prospects.

2. Data Sources

The data used in this study included the total water use consumption (agriculture, industry, and drinking), the total population, the gross regional product, and the administrative center coordinates of the 31 provincial administrative areas (excluding Hong Kong, Macao, and Taiwan; the same applies below) in China from 1965 to 2019. The total water use consumption data from 1965 to 1996 were obtained from the National Long-term Water Use Dataset of China [31], and those from 1997 to 2019 were obtained from the China Water Resources Bulletin. The total population and gross regional product from 1965 to 2019 were obtained from the China Compendium of Statistics 1949–2008 and the China Statistical Yearbook. To eliminate the effect of price factors, the gross regional product from 1965 to 2019 was uniformly converted into comparable prices to the year 1978 (1978 = 100). The administrative center coordinates of the 31 provincial administrative areas in China were measured by using Google Earth.

To discuss the study results, the data were segmented temporally and partitioned spatially. Temporally, according to the variation in the total water use consumption from 1965 to 2019 in China from the National Long-term Water Use Dataset of China and the China Water Resources Bulletin, we divided the period from 1965 to 2019 into a low-amount and fast-growth phase (1965–1980), a large-amount and slow-growth phase (1980–1997), a brief and stable adjustment phase (1997–2003), a resumed growth phase (2003–2013), and a basically stable phase (2013–2019). Spatially, according to the Chinese traditional division areas, we divided the 31 provincial administrative areas in China into the 6 major areas in China (Figure 1), namely North China (including Beijing, Tianjin, Hebei, Shanxi, Inner Mongolia, Shandong, and Henan), Northeast China (including Liaoning, Jilin, and Heilongjiang), Southeast China (including Shanghai, Jiangsu, Zhejiang, Anhui, Fujian, and Jiangxi), Central South China (including Hubei, Hunan, Guangdong, Guangxi, and Hainan), Southwest China (including Chongqing, Sichuan, Guizhou, Yunnan, and Tibet), and Northwest China (including Shaanxi, Gansu, Qinghai, Ningxia, and Xinjiang).

3. Methods

3.1. The Center of Gravity Model

The center of gravity model [32] is used to calculate the evolutionary path of the center of gravity for each index in the region at a certain time. The calculation formulae are as follows:

$$X_j=\frac{{\displaystyle \sum _{i=1}^n{M}_{ij}{X}_i}}{{\displaystyle \sum _{i=1}^n{M}_{ij}}}$$

(1)

$$Y_j=\frac{{\displaystyle \sum _{i=1}^n{M}_{ij}{Y}_i}}{{\displaystyle \sum _{i=1}^n{M}_{ij}}}$$

(2)

Here, $(X_i,Y_i)$ denotes the administrative center coordinate of the $i$th area in the region, $M_{ij}$ denotes each index’s data of the $i$th area in the region in year $j$, and $(X_j,Y_j)$ denotes the center of gravity coordinate for each index in the region in year $j$.

$${\theta }_{j_1-j_2}=\frac{n\pi }{2}+\arctan \left(\frac{Y_{j_1}-Y_{j_2}}{X_{j_1}-X_{j_2}}\right)(n=0,1,2)$$

(3)

Here, $(X_{j_1},Y_{j_1})$ denotes the center of gravity coordinate for each index in the region in year $j_1$, $(X_{j_2},Y_{j_2})$ denotes the center of gravity coordinate for each index in the region in year $j_2$, and ${\theta }_{j_1-j_2}$ denotes the center of gravity moving angle for each index in the region from year $j_1$ to year $j_2$ (−180° < ${\theta }_{j_1-j_2}$ < 180°). With due east being 0°, counterclockwise rotation is positive and clockwise rotation is negative. The corresponding relationship between the degree of ${\theta }_{j_1-j_2}$ and the center of gravity moving direction is shown in

Table 1. The corresponding relationship between the degree of ${\theta }_{j_1-j_2}$ and the center of gravity moving direction.

$\mathbf{The}\mathbf{Degree}\mathbf{of}{\mathit{\theta }}_{{\mathit{j}}_1-{\mathit{j}}_2}$	The Center of Gravity Moving Direction
$0°<{\theta }_{j_1-j_2}<90°$	North by east
$90°<{\theta }_{j_1-j_2}<180°$	North by west
$-90°<{\theta }_{j_1-j_2}<0°$	South by east
$-180°<{\theta }_{j_1-j_2}<-90°$	South by west
${\theta }_{j_1-j_2}=0°\mathrm{or}\pm 180°$	Due east or due west
${\theta }_{j_1-j_2}=\pm 90°$	Due north or due south

.

$$D_{j_1-j_2}=\mathrm{C}\times \sqrt{{\left(X_{j_1}-X_{j_2}\right)}^2+{\left(Y_{j_1}-Y_{j_2}\right)}^2}$$

(4)

Here, $\mathrm{C}$ is a constant valued at 111.111, which is the coefficient that converts the geographical coordinate (°) into the moving distance (km); $D_{j_1-j_2}$ denotes the center of gravity moving distance for each index in the region from year $j_1$ to year $j_2$.

In this paper, $(X_i,Y_i)$ ($i$ = 1, 2, …, 31) denotes the administrative center coordinate of the $i$th provincial administrative area in China, $M_{ij}$ ($j$ = 1965, 1966, …, 2019) denotes the total water use consumption, the total population, or the gross regional product of the $i$th provincial administrative area in China in year $j$, and $(X_j,Y_j)$ denotes the center of gravity coordinate for water use, the population, or the economy in China in year $j$.

3.2. The Center of Gravity Decomposed Contributions Model

The center of gravity decomposed contributions model is proposed in this research, and it is used to calculate the decomposed contributions of the evolutionary path of the center of gravity for an index in the region which an area in the region contributes to at a certain time, that is, the decomposed value contribution rate of the evolutionary path of the center of gravity for an index in the region in the longitude (latitude) direction. An area in the region exerts force on the evolutionary path of the center of gravity for an index in the region through the proportional change (increase or decrease) in the index in the region at a certain time, after which the force type for the index in the area can be judged according to the proportional change. If the proportion increases the force type is “pulling”, and the area is called a “pulling area”; if the proportion decreases the force type is “pushing”, and the area is called a “pushing area”. Additionally, the force can be decomposed into the longitude (latitude) direction, after which the corresponding decomposed value and its contribution rate appear. If the direction of the decomposed value is the same as that of the center of gravity for the index in the region at a certain time, the area is called a “same direction force decomposition area”; if the direction of the decomposed value is opposite to that of the center of gravity for the index in the region at a certain time, the area is called an “opposite direction force decomposition area”. The calculation formulae are as follows:

$$A_i=\left(\frac{M_{i{j}_2}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_2}}}-\frac{M_{i{j}_1}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_1}}}\right)\times X_i\times \gamma$$

(5)

$$B_i=\left(\frac{M_{i{j}_2}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_2}}}-\frac{M_{i{j}_1}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_1}}}\right)\times Y_i\times \gamma$$

(6)

$$\gamma =\left\{\begin{array}{ll}1& when{X}_i\ge X_{j_1}or{Y}_i\ge Y_{j_1}\\ -1& when{X}_i<X_{j_1}or{Y}_i<Y_{j_1}\end{array}\right.$$

(7)

Here, $\frac{M_{i{j}_1}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_1}}}$($\frac{M_{i{j}_2}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_2}}}$) denotes the proportion for the index in the $i$th area in year $j_1$($j_2$), and $\frac{M_{i{j}_2}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_2}}}-\frac{M_{i{j}_1}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_1}}}$ denotes the proportional change for the index in the $i$th area from year $j_1$ to year $j_2$. If $\frac{M_{i{j}_2}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_2}}}-\frac{M_{i{j}_1}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_1}}}$ > 0, the $i$th area is called a “pulling area”; if $\frac{M_{i{j}_2}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_2}}}-\frac{M_{i{j}_1}}{{\displaystyle \sum _{i=1}^n{M}_{i{j}_1}}}$ < 0, the $i$th area is called a “pushing area”. $\gamma$ denotes the direction vector; $\gamma$ = 1 indicates that the administrative center’s longitude $X_i$ (latitude $Y_i$) of the $i$th area in the region is more than or equal to the center of gravity’s longitude $X_{j_1}$ (latitude $Y_{j_1}$) for the index in the region in year $j_1$, whilst $\gamma$ = −1 indicates that the administrative center’s longitude $X_i$ (latitude $Y_i$) of the $i$th area in the region is less than the center of gravity’s longitude $X_{j_1}$ (latitude $Y_{j_1}$) for the index in the region in year $j_1$. $A_i$($B_i$) denotes the decomposed value of the evolutionary path of the center of gravity in the longitude (latitude) direction for the index in the region that the $i$th area in the region contributes to from year $j_1$ to year $j_2$.

$$Con(A_i)=\frac{\left|A_i\right|}{{\displaystyle \sum _{i=1}^n\left|A_i\right|}}\times 100\%$$

(8)

$$Con(B_i)=\frac{\left|B_i\right|}{{\displaystyle \sum _{i=1}^n\left|B_i\right|}}\times 100\%$$

(9)

Here, $Con(A_i)$ ($Con(B_i)$) denotes the decomposed value contribution rate of the evolutionary path of the center of gravity in the longitude (latitude) direction for the index in the region that the $i$th area in the region contributes to from year $j_1$ to year $j_2$.

In this paper, $A_i$($B_i$) denotes the decomposed value of the evolutionary path of the center of gravity in the longitude (latitude) direction for water use, the population, or the economy in China, which the $i$th provincial administrative area in China contributed to from 1965 to 2019; $Con(A_i)$ ($Con(B_i)$) denotes the decomposed value contribution rate of the evolutionary path of the center of gravity in the longitude (latitude) direction for water use, the population, or the economy in China, which the $i$th provincial administrative area in China contributed to from 1965 to 2019. As shown in Figure 1, according to Equations (5) and (6), the calculated decomposed value of the evolutionary path of the center of gravity in the longitude (latitude) direction for water use, the population, or the economy in China that the 31 provincial administrative areas in China contributed to from 1965 to 2019 were added for the 6 major areas in China, after which the decomposed value of the evolutionary path of the center of gravity in the longitude (latitude) direction for water use, the population, or the economy in China, which the 6 major areas in China contributed to from 1965 to 2019, was gained. According to Equations (8) and (9), the decomposed value contribution rate of the evolutionary path of the center of gravity in the longitude (latitude) direction for water use, the population, or the economy in China, which the 6 major areas in China contributed to from 1965 to 2019, were calculated.

4. Results

4.1. The Evolutionary Path of the Center of Gravity for Water Use, the Population, and the Economy in China from 1965 to 2019

4.1.1. Water Use

The center of gravity coordinates for water use in China from 1965 to 2019 were all located within the range of 111.37°~112.69° E, 32.53°~33.29° N (

Table 2. The center of gravity coordinates for water use in China from 1965 to 2019.

Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)
1965	111.62	32.53	1979	111.76	33.22	1993	112.69	32.75	2007	112.09	32.96
1966	111.58	32.74	1980	111.82	33.23	1994	112.15	32.98	2008	112.09	32.97
1967	111.49	32.83	1981	111.75	33.25	1995	112.40	32.90	2009	112.17	33.04
1968	111.43	32.83	1982	111.76	33.24	1996	112.41	32.99	2010	112.19	33.07
1969	111.54	32.91	1983	111.69	33.16	1997	112.59	33.04	2011	112.36	33.14
1970	111.72	33.08	1984	111.71	33.14	1998	112.39	33.15	2012	112.06	33.29
1971	111.37	33.12	1985	111.78	33.11	1999	112.18	33.18	2013	112.13	33.28
1972	111.40	33.14	1986	111.78	33.11	2000	112.14	33.16	2014	112.12	33.28
1973	111.70	33.00	1987	111.81	33.12	2001	112.10	33.09	2015	112.06	33.27
1974	112.04	32.94	1988	111.82	33.10	2002	112.06	32.99	2016	112.08	33.28
1975	111.72	33.18	1989	111.84	33.10	2003	111.82	32.97	2017	112.12	33.23
1976	111.73	33.15	1990	111.90	33.15	2004	112.02	32.90	2018	112.09	33.22
1977	111.80	33.25	1991	111.94	33.11	2005	111.96	32.92	2019	111.87	33.25
1978	111.77	33.27	1992	112.03	33.07	2006	112.06	32.99

) in Xiangyang City in Hubei Province (1965) as well as Nanyang City in Henan Province (1966–2019) (Figure 2). In China from 1965 to 2019 as a whole, the center of gravity cumulative yearly moving distance for water use was 835.77 km, with an average of 15.48 km, a maximum of 82.02 km (1992–1993), and a minimum of 0.37 km (1985–1986), and the center of gravity moving direction as well as angle were north by east, 18.95°. In each stage, the center of gravity cumulative yearly moving distance for water use was 281.81 km, 273.85 km, 101.95 km, 131.90 km, and 46.26 km, with an average of 18.79 km, 16.11 km, 16.99 km, 13.19 km, and 7.71 km, and the center of gravity moving direction as well as angle were north by east, 15.60°; south by east, 76.41°; south by west, 84.31°; north by east, 45.02°; and south by west, 84.41° (

Table 3. The evolutionary path of the center of gravity for water use in China from 1965 to 2019.

Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)
1965–1966	24.20	1986–1987	3.31	2007–2008	1.41	1997–2003	101.95
1966–1967	13.92	1987–1988	2.42	2008–2009	11.65	Average	16.99
1967–1968	6.51	1988–1989	1.78	2009–2010	4.44	Direction	South by west
1968–1969	15.18	1989–1990	8.44	2010–2011	20.45	Angle	84.31°
1969–1970	27.24	1990–1991	6.58	2011–2012	37.79	2003–2013	131.90
1970–1971	39.56	1991–1992	9.96	2012–2013	7.78	Average	13.19
1971–1972	3.93	1992–1993	82.02	2013–2014	0.62	Direction	North by east
1972–1973	36.67	1993–1994	65.15	2014–2015	6.95	Angle	45.02°
1973–1974	38.34	1994–1995	29.35	2015–2016	2.60	2013–2019	46.26
1974–1975	44.27	1995–1996	10.87	2016–2017	7.43	Average	7.71
1975–1976	3.20	1996–1997	20.79	2017–2018	3.35	Direction	South by west
1976–1977	13.18	1997–1998	24.72	2018–2019	25.31	Angle	84.41°
1977–1978	4.16	1998–1999	24.23	In Each Stage		As a Whole
1978–1979	5.69	1999–2000	5.33	1965–1980	281.81	1965–2019	835.77
1979–1980	5.75	2000–2001	8.13	Average	18.79	Average	15.48
1980–1981	7.66	2001–2002	12.73	Direction	North by east	Maximum	82.02
1981–1982	1.15	2002–2003	26.80	Angle	15.60°	Year	1992–1993
1982–1983	12.41	2003–2004	23.14	1980–1997	273.85	Minimum	0.37
1983–1984	3.01	2004–2005	6.56	Average	16.11	Year	1985–1986
1984–1985	8.57	2005–2006	14.02	Direction	South by east	Direction	North by East
1985–1986	0.37	2006–2007	4.65	Angle	76.41°	Angle	18.95°

).

4.1.2. Population

The center of gravity coordinates for the population in China from 1965 to 2019 were all located within the range of 113.40°~113.75° E, 32.23°~32.77° N (

Table 4. The center of gravity coordinates for the population in China from 1965 to 2019.

Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)
1965	113.75	32.77	1979	113.56	32.69	1993	113.49	32.59	2007	113.46	32.48
1966	113.73	32.76	1980	113.55	32.69	1994	113.47	32.57	2008	113.46	32.48
1967	113.71	32.76	1981	113.55	32.68	1995	113.47	32.56	2009	113.52	32.47
1968	113.69	32.75	1982	113.55	32.68	1996	113.47	32.55	2010	113.56	32.49
1969	113.68	32.75	1983	113.55	32.68	1997	113.45	32.54	2011	113.55	32.46
1970	113.66	32.74	1984	113.55	32.67	1998	113.44	32.52	2012	113.55	32.43
1971	113.64	32.74	1985	113.54	32.66	1999	113.43	32.51	2013	113.54	32.40
1972	113.62	32.74	1986	113.53	32.65	2000	113.43	32.49	2014	113.53	32.37
1973	113.60	32.73	1987	113.53	32.64	2001	113.42	32.48	2015	113.50	32.35
1974	113.58	32.73	1988	113.52	32.63	2002	113.42	32.47	2016	113.48	32.32
1975	113.56	32.72	1989	113.52	32.63	2003	113.41	32.46	2017	113.46	32.29
1976	113.55	32.71	1990	113.51	32.64	2004	113.40	32.45	2018	113.44	32.26
1977	113.55	32.70	1991	113.50	32.62	2005	113.45	32.49	2019	113.42	32.23
1978	113.55	32.70	1992	113.50	32.61	2006	113.46	32.48

) in Zhumadian City in Henan Province (1965–1993), Nanyang City in Henan Province (1994–2016), and Suizhou City in Hubei Province (2017–2019) (Figure 3). In China from 1965 to 2019 as a whole, the center of gravity cumulative yearly moving distance for the population was 113.40 km, with an average of 2.10 km, a maximum of 7.43 km (2008–2009), and a minimum of 0.43 km (1978–1979), and the center of gravity moving direction as well as angle were south by west, 31.50°. In each stage, the center of gravity cumulative yearly moving distance for the population was 26.21 km, 22.04 km, 10.32 km, 32.33 km, and 22.50 km, with an average of 1.75 km, 1.30 km, 1.72 km, 3.23 km, and 3.75 km, and the center of gravity moving direction as well as angle were south by west, 67.13°; south by west, 32.94°; south by west, 32.25°; south by east, 64.02°; and south by west, 35.01° (

Table 5. The evolutionary path of the center of gravity for the population in China from 1965 to 2019.

Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)
1965–1966	3.27	1986–1987	0.86	2007–2008	0.52	1997–2003	10.32
1966–1967	2.07	1987–1988	1.33	2008–2009	7.43	Average	1.72
1967–1968	1.96	1988–1989	0.49	2009–2010	4.31	Direction	South by west
1968–1969	1.37	1989–1990	1.33	2010–2011	3.71	Angle	32.25°
1969–1970	2.59	1990–1991	1.96	2011–2012	3.60	2003–2013	32.33
1970–1971	1.96	1991–1992	1.79	2012–2013	3.19	Average	3.23
1971–1972	2.18	1992–1993	2.18	2013–2014	3.06	Direction	South by east
1972–1973	2.32	1993–1994	2.67	2014–2015	3.85	Angle	64.02°
1973–1974	2.51	1994–1995	1.08	2015–2016	3.93	2013–2019	22.50
1974–1975	2.17	1995–1996	0.97	2016–2017	4.39	Average	3.75
1975–1976	1.41	1996–1997	2.14	2017–2018	3.96	Direction	South by west
1976–1977	0.95	1997–1998	2.21	2018–2019	3.30	Angle	35.01°
1977–1978	0.53	1998–1999	1.99	In Each Stage		As a Whole
1978–1979	0.43	1999–2000	2.35	1965–1980	26.21	1965–2019	113.40
1979–1980	0.50	2000–2001	1.17	Average	1.75	Average	2.10
1980–1981	0.68	2001–2002	1.22	Direction	South by west	Maximum	7.43
1981–1982	0.46	2002–2003	1.40	Angle	67.13°	Year	2008–2009
1982–1983	0.55	2003–2004	1.46	1980–1997	22.04	Minimum	0.43
1983–1984	0.85	2004–2005	6.78	Average	1.30	Year	1978–1979
1984–1985	1.10	2005–2006	0.64	Direction	South by west	Direction	South by west
1985–1986	1.59	2006–2007	0.69	Angle	32.94°	Angle	31.50°

).

4.1.3. Economy

The center of gravity coordinates for the economy in China from 1965 to 2019 were all located within the range of 114.86°~115.47 °E, 32.26°~33.86 °N (

Table 6. The center of gravity coordinates for the economy in China from 1965 to 2019.

Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)	Year	Longitude (°E)	Latitude (°N)
1965	114.86	33.49	1979	115.25	33.73	1993	115.20	32.82	2007	115.44	32.47
1966	114.94	33.62	1980	115.27	33.69	1994	115.26	32.72	2008	115.45	32.49
1967	114.92	33.51	1981	115.28	33.55	1995	115.28	32.66	2009	115.45	32.54
1968	115.25	33.58	1982	115.20	33.48	1996	115.31	32.64	2010	115.43	32.52
1969	115.28	33.65	1983	115.20	33.58	1997	115.33	32.62	2011	115.38	32.52
1970	115.33	33.81	1984	115.22	33.58	1998	115.33	32.60	2012	115.32	32.54
1971	115.29	33.80	1985	115.22	33.49	1999	115.35	32.58	2013	115.29	32.53
1972	115.29	33.62	1986	115.21	33.43	2000	115.37	32.57	2014	115.25	32.50
1973	115.35	33.73	1987	115.25	33.41	2001	115.39	32.57	2015	115.19	32.44
1974	115.47	33.78	1988	115.28	33.38	2002	115.40	32.55	2016	115.11	32.36
1975	115.38	33.86	1989	115.24	33.36	2003	115.42	32.50	2017	115.09	32.32
1976	115.40	33.86	1990	115.14	33.27	2004	115.43	32.49	2018	115.08	32.28
1977	115.27	33.80	1991	115.12	33.16	2005	115.44	32.50	2019	115.05	32.26
1978	115.27	33.78	1992	115.16	32.99	2006	115.44	32.49

) in Zhoukou City in Henan Province (1965–1991), Fuyang City in Anhui Province (1992–1999, 2009), and Xinyang City in Henan Province (2000–2008, 2010–2019) (Figure 4). In China from 1965 to 2019 as a whole, the center of gravity cumulative yearly moving distance for the economy was 449.83 km, with an average of 8.33 km, a maximum of 37.86 km (1967–1968), and a minimum of 1.36 km (2004–2005), and the center of gravity moving direction as well as angle was south by east, 8.63°. In each stage, the center of gravity cumulative yearly moving distance for the economy was 191.83 km, 163.88 km, 18.79 km, 33.92 km, and 41.42 km, with an average of 12.79 km, 9.64 km, 3.13 km, 3.39 km, and 6.90 km, and the center of gravity moving direction as well as angle were north by east, 64.23°; south by east, 2.95°; south by east, 37.62°; north by west, 76.35°; and south by west, 41.82° (

Table 7. The evolutionary path of the center of gravity for the economy in China from 1965 to 2019.

Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)	Year	Cumulative Yearly Moving Distance (km)
1965–1966	16.55	1986–1987	5.73	2007–2008	2.20	1997–2003	18.79
1966–1967	12.46	1987–1988	4.70	2008–2009	5.38	Average	3.13
1967–1968	37.86	1988–1989	5.34	2009–2010	3.14	Direction	South by east
1968–1969	8.50	1989–1990	15.02	2010–2011	6.54	Angle	37.62°
1969–1970	18.53	1990–1991	12.21	2011–2012	6.03	2003–2013	33.92
1970–1971	4.08	1991–1992	19.28	2012–2013	3.83	Average	3.39
1971–1972	20.23	1992–1993	19.82	2013–2014	5.72	Direction	North by west
1972–1973	14.41	1993–1994	12.72	2014–2015	9.02	Angle	76.35°
1973–1974	14.45	1994–1995	7.57	2015–2016	12.90	2013–2019	41.42
1974–1975	13.53	1995–1996	3.03	2016–2017	5.38	Average	6.90
1975–1976	1.66	1996–1997	3.26	2017–2018	4.17	Direction	South by west
1976–1977	16.00	1997–1998	2.93	2018–2019	4.23	Angle	41.82°
1977–1978	2.14	1998–1999	2.87	In Each Stage		As a Whole
1978–1979	6.23	1999–2000	2.58	1965–1980	191.83	1965–2019	449.83
1979–1980	5.20	2000–2001	1.76	Average	12.79	Average	8.33
1980–1981	15.36	2001–2002	3.47	Direction	North by east	Maximum	37.86
1981–1982	11.75	2002–2003	5.18	Angle	64.23°	Year	1967–1968
1982–1983	10.46	2003–2004	2.31	1980–1997	163.88	Minimum	1.36
1983–1984	1.55	2004–2005	1.36	Average	9.64	Year	2004–2005
1984–1985	10.15	2005–2006	1.42	Direction	South by east	Direction	South by east
1985–1986	5.93	2006–2007	1.72	Angle	2.95°	Angle	8.63°

).

4.2. The Decomposed Contributions of the Evolutionary Path of the Center of Gravity for Water Use, the Population, and the Economy in China from 1965 to 2019

4.2.1. Water Use

As shown in

Table 8. The decomposed contributions of the evolutionary path of the center of gravity for water use in China from 1965 to 2019, which the 31 provincial administrative areas in China contributed to.

Area	Force Type	Decomposed Value in the Longitude Direction				Decomposed Value in the Latitude Direction
		Value (°E)	Direction	Area	Contribution Rate (%)	Value (°N)	Direction	Area	Contribution Rate (%)
Beijing	Pushing	−0.57	West	Opposite	1.99	−0.20	South	Opposite	2.40
Tianjin	Pushing	−0.29	West	Opposite	1.00	−0.10	South	Opposite	1.18
Hebei	Pushing	−0.53	West	Opposite	1.84	−0.18	South	Opposite	2.15
Shanxi	Pushing	−0.19	West	Opposite	0.67	−0.07	South	Opposite	0.80
Inner Mongolia	Pushing	−0.43	West	Opposite	1.50	−0.16	South	Opposite	1.93
Liaoning	Pushing	−0.23	West	Opposite	0.78	−0.08	South	Opposite	0.93
Jilin	Pulling	1.10	East	Same	3.81	0.38	North	Same	4.69
Heilongjiang	Pulling	4.38	East	Same	15.17	1.59	North	Same	19.32
Shanghai	Pushing	−1.18	West	Opposite	4.10	0.30	North	Same	3.71
Jiangsu	Pulling	0.91	East	Same	3.14	−0.24	South	Opposite	2.98
Zhejiang	Pushing	−0.83	West	Opposite	2.87	0.21	North	Same	2.55
Anhui	Pushing	−0.38	West	Opposite	1.31	0.10	North	Same	1.26
Fujian	Pushing	−3.06	West	Opposite	10.61	0.67	North	Same	8.16
Jiangxi	Pulling	0.35	East	Same	1.22	−0.09	South	Opposite	1.06
Shandong	Pulling	0.80	East	Same	2.78	0.25	North	Same	3.06
Henan	Pulling	1.51	East	Same	5.23	0.46	North	Same	5.62
Hubei	Pulling	1.29	East	Same	4.48	−0.35	South	Opposite	4.22
Hunan	Pushing	−2.41	West	Opposite	8.36	0.60	North	Same	7.35
Guangdong	Pushing	−2.02	West	Opposite	6.98	0.41	North	Same	5.02
Guangxi	Pulling	−1.20	West	Opposite	4.16	−0.25	South	Opposite	3.08
Hainan	Pushing	0.89	East	Same	3.09	0.16	North	Same	1.97
Chongqing	Pulling	−0.47	West	Opposite	1.64	−0.13	South	Opposite	1.60
Sichuan	Pulling	−0.76	West	Opposite	2.64	−0.22	South	Opposite	2.74
Guizhou	Pulling	−1.03	West	Opposite	3.56	−0.26	South	Opposite	3.13
Yunnan	Pushing	0.09	East	Same	0.31	0.02	North	Same	0.27
Tibet	Pulling	−0.31	West	Opposite	1.07	−0.10	South	Opposite	1.22
Shaanxi	Pulling	−0.45	West	Opposite	1.54	0.14	North	Same	1.71
Gansu	Pushing	0.40	East	Same	1.39	−0.14	South	Opposite	1.69
Qinghai	Pushing	0.18	East	Same	0.63	−0.07	South	Opposite	0.80
Ningxia	Pushing	0.17	East	Same	0.59	−0.06	South	Opposite	0.75
Xinjiang	Pushing	0.44	East	Same	1.53	−0.22	South	Opposite	2.68

, among the decomposed contributions of the evolutionary path of the center of gravity for water use in China from 1965 to 2019, which the 31 provincial administrative areas in China contributed to, in terms of the force type, 13 areas, including Jilin, were “pulling areas”, whilst 18 areas, including Beijing, were “pushing areas”. In terms of the decomposed value in the longitude direction, 13 areas, including Jilin, were “same direction force decomposition areas”, whilst 18 areas, including Beijing, were “opposite direction force decomposition areas”. Longitudinally, Heilongjiang contributed the most to water use in China from 1965 to 2019 (15.17%). In terms of the decomposed value in the latitude direction, 13 areas, including Jilin, were “same direction force decomposition areas”, whilst 18 areas, including Beijing, were “opposite direction force decomposition areas”. Latitudinally, Heilongjiang contributed the most to water use in China from 1965 to 2019 (19.32%). Table 7 provides more detailed information.

As shown in

Table 9. The decomposed contributions of the evolutionary path of the center of gravity for water use in China from 1965 to 2019, which the six major areas in China contributed to.

Area	Force Type	Decomposed Value in the Longitude Direction				Decomposed Value in the Latitude Direction
		Value (°E)	Direction	Area	Contribution Rate (%)	Value (°N)	Direction	Area	Contribution Rate (%)
North China	Pulling	0.29	East	Same	1.74	0.02	North	Same	0.41
Northeast China	Pulling	5.25	East	Same	32.02	1.89	North	Same	42.26
Southeast China	Pushing	−4.20	West	Opposite	25.58	0.95	North	Same	21.30
Central South China	Pushing	−3.44	West	Opposite	20.99	0.58	North	Same	12.89
Southwest China	Pulling	−2.48	West	Opposite	15.12	−0.69	South	Opposite	15.42
Northwest China	Pushing	0.75	East	Same	4.55	−0.35	South	Opposite	7.72

and Figure 5, among the decomposed contributions of the evolutionary path of the center of gravity for water use in China from 1965 to 2019, which the six major areas in China contributed to, in terms of the force type, North China, Northeast China, and Southwest China were “pulling areas”, whilst Southeast China, Central South China, and Northwest China were “pushing areas”. In terms of the decomposed value in the longitude direction, North China, Northeast China, and Northwest China were “same direction force decomposition areas”, whilst Southeast China, Central South China, and Southwest China were “opposite direction force decomposition areas”. Longitudinally, Northeast China contributed the most to water use in China from 1965 to 2019 (32.02%). In terms of the decomposed value in the latitude direction, North China, Northeast China, Southeast China, and Central South China were “same direction force decomposition areas”, whilst Southwest China and Northwest China were “opposite direction force decomposition areas”. Latitudinally, Northeast China contributed the most to water use in China from 1965 to 2019 (42.26%). Table 8 provides detailed information.

4.2.2. Population

As shown in

Table 10. The decomposed contributions of the evolutionary path of the center of gravity for the population in China from 1965 to 2019, which the 31 provincial administrative areas in China contributed to.

Area	Force Type	Decomposed Value in the Longitude Direction				Decomposed Value in the Latitude Direction
		Value (°E)	Direction	Area	Contribution Rate (%)	Value (°N)	Direction	Area	Contribution Rate (%)
Beijing	Pulling	0.54	East	Opposite	3.23	0.19	North	Opposite	3.94
Tianjin	Pulling	0.12	East	Opposite	0.70	0.04	North	Opposite	0.83
Hebei	Pushing	−0.42	West	Same	2.53	−0.14	South	Same	2.99
Shanxi	Pushing	0.12	East	Opposite	0.73	−0.04	South	Same	0.87
Inner Mongolia	Pushing	0.09	East	Opposite	0.53	−0.03	South	Same	0.69
Liaoning	Pushing	−1.05	West	Same	6.27	−0.36	South	Same	7.54
Jilin	Pushing	−0.67	West	Same	3.97	−0.23	South	Same	4.93
Heilongjiang	Pushing	−0.81	West	Same	4.86	−0.29	South	Same	6.24
Shanghai	Pulling	0.30	East	Opposite	1.79	−0.08	South	Same	1.64
Jiangsu	Pushing	−0.46	West	Same	2.75	0.12	North	Opposite	2.64
Zhejiang	Pulling	0.52	East	Opposite	3.10	−0.13	South	Same	2.77
Anhui	Pushing	−0.26	West	Same	1.57	0.07	North	Opposite	1.51
Fujian	Pulling	0.60	East	Opposite	3.58	−0.13	South	Same	2.78
Jiangxi	Pulling	0.17	East	Opposite	1.02	−0.04	South	Same	0.90
Shandong	Pushing	−0.86	West	Same	5.10	−0.27	South	Same	5.68
Henan	Pushing	0.25	East	Opposite	1.52	−0.08	South	Same	1.65
Hubei	Pushing	−0.74	West	Same	4.39	0.20	North	Opposite	4.17
Hunan	Pushing	0.78	East	Opposite	4.63	0.19	North	Opposite	4.11
Guangdong	Pulling	−3.98	West	Same	23.77	−0.81	South	Same	17.24
Guangxi	Pulling	−0.17	West	Same	0.99	−0.03	South	Same	0.74
Hainan	Pulling	−0.22	West	Same	1.32	−0.04	South	Same	0.85
Chongqing	Pushing	0.50	East	Opposite	2.99	0.14	North	Opposite	2.95
Sichuan	Pushing	1.27	East	Opposite	7.56	0.37	North	Opposite	7.91
Guizhou	Pulling	−0.23	West	Same	1.35	−0.06	South	Same	1.20
Yunnan	Pulling	−0.37	West	Same	2.18	−0.09	South	Same	1.89
Tibet	Pulling	−0.06	West	Same	0.36	−0.02	South	Same	0.42
Shaanxi	Pushing	0.18	East	Opposite	1.09	−0.06	South	Same	1.22
Gansu	Pushing	0.08	East	Opposite	0.50	−0.03	South	Same	0.62
Qinghai	Pulling	−0.10	West	Same	0.61	0.04	North	Opposite	0.78
Ningxia	Pulling	−0.21	West	Same	1.24	0.08	North	Opposite	1.59
Xinjiang	Pulling	−0.63	West	Same	3.79	0.32	North	Opposite	6.72

, among the decomposed contributions of the evolutionary path of the center of gravity for the population in China from 1965 to 2019, which the 31 provincial administrative areas in China contributed to, in terms of the force type, 15 areas, including Beijing, were “pulling areas”, whilst 16 areas, including Hebei, were “pushing areas”. In terms of the decomposed value in the longitude direction, 17 areas, including Hebei, were “same direction force decomposition areas”, whilst 14 areas, including Beijing, were “opposite direction force decomposition areas”. Longitudinally, Guangdong contributed the most to the population in China from 1965 to 2019 (23.77%). In terms of the decomposed value in the latitude direction, 20 areas, including Hebei, were “same direction force decomposition areas”, whilst 11 areas, including Beijing, were “opposite direction force decomposition areas”. Latitudinally, Guangdong contributed the most to the population in China from 1965 to 2019 (17.24%). Table 9 provides detailed information.

As shown in

Table 11. The decomposed contributions of the evolutionary path of the center of gravity for the population in China from 1965 to 2019, which the six major areas in China contributed to.

Area	Force Type	Decompose Value in the Longitude Direction				Decompose Value in the Latitude Direction
		Value (°E)	Direction	Area	Contribution Rate (%)	Value (°N)	Direction	Area	Contribution Rate (%)
North China	Pushing	−0.15	West	Same	1.59	−0.34	South	Same	12.95
Northeast China	Pushing	−2.53	West	Same	26.16	−0.88	South	Same	34.09
Southeast China	Pulling	0.87	East	Opposite	8.96	−0.19	South	Same	7.17
Central South China	Pulling	−4.33	West	Same	44.76	−0.50	South	Same	19.20
Southwest China	Pushing	1.12	East	Opposite	11.54	0.35	North	Opposite	13.39
Northwest China	Pulling	−0.68	West	Same	6.99	0.34	North	Opposite	13.20

and Figure 6, among the decomposed contributions of the evolutionary path of the center of gravity for the population in China from 1965 to 2019, which the six major areas in China contributed to, in terms of the force type, Southeast China, Central South China, and Northwest China were “pulling areas”, whilst North China, Northeast China, and Southwest China were “pushing areas”. In terms of the decomposed value in the longitude direction, North China, Northeast China, Central South China, and Northwest China were “same direction force decomposition areas”, whilst Southeast China and Southwest China were “opposite direction force decomposition areas”. Longitudinally, Central South China contributed the most to the population in China from 1965 to 2019 (44.76%). In terms of the decomposed value in the latitude direction, North China, Northeast China, Southeast China, and Central South China were “same direction force decomposition areas”, whilst Southwest China and Northwest China were “opposite direction force decomposition areas”. Latitudinally, Northeast China contributed the most to the population in China from 1965 to 2019 (34.09%). Table 10 provides detailed information.

4.2.3. Economy

As shown in

Table 12. The decomposed contributions of the evolutionary path of the center of gravity for the economy in China from 1965 to 2019, which the 31 provincial administrative areas in China contributed to.

Area	Force Type	Decomposed Value in the Longitude Direction				Decomposed Value in the Latitude Direction
		Value (°E)	Direction	Area	Contribution Rate (%)	Value (°N)	Direction	Area	Contribution Rate (%)
Beijing	Pushing	−0.55	West	Opposite	1.26	−0.19	South	Same	1.53
Tianjin	Pulling	0.35	East	Same	0.81	0.12	North	Opposite	0.95
Hebei	Pushing	0.23	East	Same	0.52	−0.08	South	Same	0.61
Shanxi	Pushing	1.80	East	Same	4.13	−0.60	South	Same	4.91
Inner Mongolia	Pulling	−0.16	West	Opposite	0.36	0.06	North	Opposite	0.46
Liaoning	Pushing	−2.69	West	Opposite	6.19	−0.91	South	Same	7.41
Jilin	Pushing	−1.48	West	Opposite	3.39	−0.52	South	Same	4.19
Heilongjiang	Pushing	−3.88	West	Opposite	8.93	−1.41	South	Same	11.43
Shanghai	Pushing	−2.83	West	Opposite	6.51	0.73	North	Opposite	5.91
Jiangsu	Pulling	6.76	East	Same	15.54	−1.82	South	Same	14.83
Zhejiang	Pulling	2.50	East	Same	5.74	−0.63	South	Same	5.12
Anhui	Pushing	−0.33	West	Opposite	0.76	0.09	North	Opposite	0.73
Fujian	Pulling	2.29	East	Same	5.25	−0.50	South	Same	4.06
Jiangxi	Pushing	−1.11	West	Opposite	2.56	0.28	North	Opposite	2.24
Shandong	Pulling	2.89	East	Same	6.65	0.91	North	Opposite	7.36
Henan	Pulling	−0.96	West	Opposite	2.20	0.29	North	Opposite	2.37
Hubei	Pushing	0.91	East	Same	2.08	0.24	North	Opposite	1.97
Hunan	Pushing	0.89	East	Same	2.04	0.22	North	Opposite	1.81
Guangdong	Pulling	−5.81	West	Opposite	13.37	−1.19	South	Same	9.65
Guangxi	Pushing	0.61	East	Same	1.40	0.13	North	Opposite	1.04
Hainan	Pulling	−0.13	West	Opposite	0.30	−0.02	South	Same	0.19
Chongqing	Pushing	0.37	East	Same	0.86	0.10	North	Opposite	0.84
Sichuan	Pushing	0.96	East	Same	2.20	0.28	North	Opposite	2.29
Guizhou	Pushing	0.62	East	Same	1.43	0.16	North	Opposite	1.26
Yunnan	Pushing	0.82	East	Same	1.89	0.20	North	Opposite	1.63
Tibet	Pushing	0.02	East	Same	0.05	0.01	North	Opposite	0.05
Shaanxi	Pushing	0.25	East	Same	0.57	−0.08	South	Same	0.63
Gansu	Pushing	0.47	East	Same	1.07	−0.16	South	Same	1.32
Qinghai	Pushing	0.14	East	Same	0.32	−0.05	South	Same	0.41
Ningxia	Pushing	0.07	East	Same	0.17	−0.03	South	Same	0.22
Xinjiang	Pushing	0.63	East	Same	1.46	−0.32	South	Same	2.57

, among the decomposed contributions of the evolutionary path of the center of gravity for the economy in China from 1965 to 2019, which the 31 provincial administrative areas in China contributed to, in terms of the force type, 9 areas, including Tianjin, were “pulling areas”, whilst 22 areas, including Beijing, were “pushing areas”. In terms of the decomposed value in the longitude direction, 20 areas, including Tianjin, were “same direction force decomposition areas”, whilst 11 areas, including Beijing, were “opposite direction force decomposition areas”. Longitudinally, Jiangsu contributed the most to the economy in China from 1965 to 2019 (15.54%). In terms of the decomposed value in the latitude direction, 16 areas, including Beijing, were “same direction force decomposition areas”, whilst 15 areas, including Tianjin, were “opposite direction force decomposition areas”. Latitudinally, Jiangsu contributed the most to the economy in China from 1965 to 2019 (14.83%). Table 11 provides detailed information.

As shown in

Table 13. The decomposed contributions of the evolutionary path of the center of gravity for the economy in China from 1965 to 2019, which the six major areas in China contributed to.

Area	Force Type	Decomposed Value in the Longitude Direction				Decomposed Value in the Latitude Direction
		Value (°E)	Direction	Area	Contribution Rate (%)	Value (°E)	Direction	Area	Contribution Rate (%)
North China	Pulling	3.61	East	Same	13.44	0.50	North	Opposite	7.01
Northeast China	Pushing	−8.05	West	Opposite	30.02	−2.83	South	Same	39.37
Southeast China	Pulling	7.27	East	Same	27.10	−1.86	South	Same	25.84
Central South China	Pulling	−3.54	West	Opposite	13.21	−0.62	South	Same	8.59
Southwest China	Pushing	2.79	East	Same	10.41	0.75	North	Opposite	10.38
Northwest China	Pushing	1.56	East	Same	5.82	−0.63	South	Same	8.80

and Figure 7, among the decomposed contributions of the evolutionary path of the center of gravity for the economy in China from 1965 to 2019, which the six major areas in China contributed to, in terms of the force type, North China, Southeast China, and Central South China were “pulling areas”, whilst Northeast China, Southwest China, and Northwest China were “pushing areas”. In terms of the decomposed value in the longitude direction, North China, Southeast China, Southwest China, and Northwest China were “same direction force decomposition areas”, whilst Northeast China and Central South China were “opposite direction force decomposition areas”. Longitudinally, Northeast China contributed the most to the economy in China from 1965 to 2019 (30.02%). In terms of the decomposed value in the latitude direction, Northeast China, Southeast China, Central South China, and Northwest China were “same direction force decomposition areas”, whilst North China and Southwest China were “opposite direction force decomposition areas”. Latitudinally, Northeast China contributed the most to the economy in China from 1965 to 2019 (39.37%). Table 12 provides detailed information.

5. Discussion

5.1. Comparison of the Evolutionary Path of the Center of Gravity for Water Use, the Population, and the Economy in China from 1965 to 2019

From the center of gravity cumulative yearly moving distance for water use, the population, and the economy in China from 1965 to 2019 as a whole, water resources are mobile and renewable resources, showing complex links with the environment and ecology; water resources are difficult to regulate, resulting in the center of gravity cumulative yearly moving distance for water use (835.77 km) being larger than that of the population (113.40 km) and economy (449.83 km). Compared with the agglomeration of the economic factor, more factors limit the movement of population flow, and population migration has a certain degree of inertia, resulting in the center of gravity cumulative yearly moving distance for the economy (449.83 km) being larger than that of the population (113.40 km).

From the center of gravity moving direction for water use, the population, and the economy in China from 1965 to 2019 as a whole, North China and Northeast China, as important agricultural cultivation areas and industrial bases in China, needed more water for agriculture and industry, resulting in the center of gravity moving direction for water use being north by east [33]. After China proposed the “Family Planning” policy, Southwest China, which had a large minority population, was less constrained, resulting in the center of gravity moving direction for the population being south by west [34]. After China proposed the “Reform and Opening Up” policy, the economy of Southeast China strengthened, resulting in the center of gravity moving direction for the economy being south by east [35].

From the center of gravity moving direction for water use, the population, and the economy in China from 1965 to 2019 in each stage, China launched a pilot scheme for the employment of migrant workers in cities at the beginning of the 21st century; thereafter, many migrant workers moved to cities in Southeast China for employment, resulting in the center of gravity moving direction for the population being south by east from 2003 to 2013. China had attached considerable importance to the economy and infrastructure construction in Northeast China since its founding in 1949, resulting in the center of gravity moving direction for the economy being north by east from 1965 to 1980. China proposed the “Western Development” policy at the beginning of the 21st century; the gross regional product in the western part of China increased rapidly, resulting in the center of gravity moving direction for the economy being north by west from 2003 to 2013. China proposed the “Precise Poverty Alleviation” policy in 2014; many families in the western part of China were lifted out of poverty, resulting in the center of gravity moving direction for the economy being south by west from 2013 to 2019 (generally consistent with the results in the literature [36]). Because water use patterns are influenced by the population, the economy, and other factors, resulting in the center of gravity moving direction for water use being south by east from 1980 to 1997 (the same moving direction as the center of gravity for the economy from 1980 to 1997), south by west from 1997 to 2003 (the same moving direction as the center of gravity for the population from 1997 to 2003), and south by west from 2013 to 2019 (the same moving direction as the center of gravity for the population and the economy from 2013 to 2019). The center of gravity moving direction for water use, the population, and the economy in China from 1965 to 2019 in each stage in other cases was consistent with those from 1965 to 2019 as a whole.

5.2. Comparison on the Decomposed Contributions of the Evolutionary Path of the Center of Gravity for Water Use, the Population, and the Economy in China from 1965 to 2019, Which the Six Major Areas in China Contributed to

From the decomposed value contribution rate of the evolutionary path of the center of gravity in the latitude direction for water use, the population, and the economy in China from 1965 to 2019, which the six major areas in China contributed to, Northeast China contributed the most (42.26%, 34.09%, and 39.37%, respectively). China had built cross-basin water transfer projects, such as diverting water from the south to the north, resulting in an increase in the proportion of the total water use consumption of Northeast China to the whole country, and the direction of the decomposed value contribution rate of the evolutionary path of the center of gravity in the latitude direction for water use was north, which was the same direction as the center of gravity moving direction for water use in China from 1965 to 2019 as a whole. This showed that the increasing proportion of total water use consumption in Northeast China most positively affected the evolutionary path of the center of gravity for water use in China moving northwards from 1965 to 2019. The implementation of the “Family Planning” policy in Northeast China was stricter than the other five major areas in China, and the lack of natural resources led to a southward tendency of economic activity, resulting in a decrease in the proportion of the total population as well as gross regional product in Northeast China to the whole country, and the direction of the decomposed value contribution rate of the evolutionary path of the center of gravity in the latitude direction for the population and the economy was south, which was the same direction as the center of gravity moving direction for the population and the economy in China from 1965 to 2019 as a whole. This showed that the decreasing proportion of the total population and the gross regional product in Northeast China most negatively affected the evolutionary path of the center of gravity for the population and the economy in China moving southwards from 1965 to 2019.

6. Conclusions and Future Prospects

6.1. Conclusions

We calculated the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019 via the use of the center of gravity model. The evolutionary path of the center of gravity for water use was mainly affected by water resource regulation difficulties, the population, the economy and so on. As a whole, the center of gravity cumulative yearly moving distance for water use was 835.77 km, and the center of gravity moving direction as well as angle were north by east, 18.95°. In each stage, the center of gravity moving direction as well as angle was north by east, 15.60°; south by east, 76.41°; south by west, 84.31°; north by east, 45.02°; and south by west, 84.41°. The evolutionary path of the center of gravity for the population was mainly affected by population migration inertia, the “Family Planning” policy, and so on. As a whole, the center of gravity cumulative yearly moving distance for the population was 113.40 km, and the center of gravity moving direction as well as angle were south by west, 31.50°. In each stage, the center of gravity moving direction as well as angle were south by west, 67.13°; south by west, 32.94°; south by west, 32.25°; south by east, 64.02°; and south by west, 35.01°. The evolutionary path of the center of gravity for the economy was mainly affected by factor agglomeration, the “Reform and Opening up” policy, the “Western Development” policy, the “Precise Poverty Alleviation” policy, and so on. As a whole, the center of gravity cumulative yearly moving distance for the economy was 449.83 km, and the center of gravity moving direction as well as angle were south by east, 8.63°. In each stage, the center of gravity moving direction as well as angle were north by east, 64.23°; south by east, 2.95°; south by east, 37.62°; north by west, 76.35°; and south by west, 41.82°.

We calculated the decomposed contributions of the evolutionary path of the center of gravity for water use, the population, and the economy in China from 1965 to 2019, which the six major areas in China contributed to by using the center of gravity decomposed contribution model. From the decomposed value contribution rate of the evolutionary path of the center of gravity in the latitude direction for water use, the population, and the economy in China from 1965 to 2019, which the six major areas in China contributed to, Northeast China contributed the most (42.26%, 34.09%, and 39.37%, respectively). The increasing proportion of total water use consumption in Northeast China most positively affected the evolutionary path of the center of gravity for water use in China moving northwards from 1965 to 2019, and the decreasing proportion of the total population as well as the gross regional product in Northeast China most negatively affected the evolutionary path of the center of gravity for population and economy in China moving southwards from 1965 to 2019.

6.2. Future Prospects

The center of gravity model can reflect the multiyear spatiotemporal evolution for Chinese water use, the population, and the economy in China from the perspective of time and space. In recent years, more and more people in Northern China are migrating to Southern China, which has better geographical conditions for living, and the economic growth gap between Northern China and Southern China has gradually become more pronounced, presenting an expanding trend. Our conclusion that the centers of gravity for the population and the economy in China from 1965 to 2019 as a whole were moving southwards demonstrates the seriousness of the problem. At the same time, the foundation of water resource endowment in Northern China is relatively weak. Compared with Southern China, Northern China needs more water use to maintain its population and economic development. Therefore, the center of gravity for water use in China from 1965 to 2019 as a whole was moving northwards.

The center of gravity moving direction for water use was opposite to those for the population and the economy in China from 1965 to 2019 as a whole, resulting in a longer distance between the center of gravity for water use and the center of gravity for the population and the economy, which further illustrates the increasingly prominent contradictions between water use, the population, and the economy in China, so we should pay attention to the impact caused by water resource constraints on the economic growth gap between Northern China and Southern China. The center of gravity model could not completely explain how water use, the population, and the economy affect each other, so we need to study the internal influence mechanisms of the above three via the integration of other mathematical models in the future, and corresponding policies must be formulated and improved for coordinated regional development and water resource management based on understanding the overview of water use, the population, and the economy between Northern China and Southern China, so as to better serve the synergistic issue between the sustainable utilization of water resources and the sustainable development of the population as well as the economy.