Analysis on the Evolution of Rural Settlement Pattern and Its Influencing Factors in China from 1995 to 2015

Abstract

Since the early 1990s, China has experienced rapid industrialization and urbanization. As cities have expanded rapidly, the spatial patterns of rural settlements also changed significantly. This study uses land use data from satellite imagery interpretation, socioeconomic statistics, and field survey data, together with techniques including landscape pattern analysis, kernel density estimation, and spatial measurement models, to analyze the evolving spatial patterns of rural settlements influencing factors in China from 1995 to 2015. The results indicate the following: First, China’s rural settlements experienced significant changes in the period 1995–2015, as 88.92% of Prefectural-level administrative district units saw an increase in rural settlement area, with total settlement size increasing by 1.35 million hectares, and settlement area sprawl index values can be summarized as “high in the west and low in the east”. Second, in the two-decade study period, the population agglomeration capacity of rural settlements in China continuously weakened, and the shape and structure of rural settlement became more complex and irregular. The scale and scope of the disappearance of rural settlement areas in the northeast and southeast regions was relatively drastic, and the kernel density value of settlements dropped significantly. Third, the increase in rural settlement land area is concentrated in low-altitude and low-slope areas, with a significant tendency to be near water and roads. Fourth, social and economic factors, such as per capita net income of rural residents, the proportion of the population employed in agriculture, the size and structure of the permanent rural population, local fiscal revenue, and urbanization level, are the main factors that cause changes of rural settlement patterns. The results of this study can serve as a reference for promoting regional rural sustainable development policies and advancing rural spatial governance and comprehensive revitalization.

1. Introduction

Since industrialization began, urbanization has altered urban spaces, but it has also profoundly affected rural settlements land [1]. Usually, a rural settlement is a population of a certain size that is engaged in work related to agriculture production, and it is the phenomenon, form, and process of people gathering in a specific geographical space. The spatio-temporal evolution of rural settlements can be viewed as reflective of the man-land relationship in rural space during the process of rapid urbanization, as it reflects the relationship between human activities and the surrounding environment under different productivity conditions [2,3,4]. This study considers that rural settlements are the living places of various forms of human beings in rural areas, including all villages and a small number of industrial enterprises and commercial service facilities. The formation and evolution of rural settlements are hindered and restricted by various factors. Settlement evolution is a concentrated expression of economic and social development, and it reflects the activities of the rural population and their distribution in geographic spatial units during a certain period of time [5,6].

Due to global industrialization, urbanization, and population growth, the social relationship between urban and rural areas has undergone drastic changes, with variations in the structure of rural settlements due to rapid urbanization becoming a common phenomenon. The developed countries and regions of the world have paid attention to rural settlements for a long time and made progress in their research in that area. In terms of methods, the description of village distribution and original form has been transformed into quantitative analysis, behavioral revolution, and cultural transformation. Landscape types and land use patterns of rural settlements are explored based on GIS technology, and landscape ecology and kernel density analysis are often applied to rural settlements [7,8]. In content, the international community has long been concerned about the changes in the size and number of rural settlements. For example, researchers have tracked and monitored rural settlements in Central and Eastern Europe and the United States and found that the size of rural settlements is generally increasing, with some villages gradually growing into key settlements [9,10]. The shape of rural settlements was simple because it was not subject to significant human disturbance during the period of traditional agriculture. However, under the influence of rapid urbanization, rural settlements have become increasingly complex and diverse [11]. In the course of socioeconomic transformation, there are disorderly flows of rural elements of production and unequal urban and rural development. Rural space reconstruction is realized through the reconstruction of residential spaces, improvements to rural structural networks, and the co-development and sharing of factors of production between urban and rural areas [12,13]. Studies on the settlement location selection and spatial distribution, the importance of natural conditions, natural resources, and accessibility are emphasized. Research also suggests that factors such as topography, climate, water resources, and transportation facilities play a decisive role in the formation and development of settlements [14,15]. In addition, the changing size of rural settlements has been shown to be impacting ecosystems [16].

Since the Chinese government began implementing market-oriented reforms, China’s industrialization and urbanization have accelerated, and it has experienced unprecedented urban and rural economic and social development, which has had a significant and far-reaching effect on rural settlement patterns. One study has revealed the hollowing out of rural settlements in the course of China’s rapid urbanization [17], and another analyzed the spatial layout of specialized villages in China [18]. Scholars have analyzed changes in the land use patterns of rural settlements in the Beijing–Tianjin–Hebei region and the Yellow River basin [19,20], looked at changes in rural settlements and the environment [21,22], and analyzed the spatial heterogeneity of rural settlements in terms of their landscape ecology [23,24]. Other studies have discussed factors affecting the development and formation of rural settlements, such as the natural geographic environment, economic conditions, and policy mechanisms [25,26,27]. Through a literature review, we found that previous studies on rural settlements focused on specific areas, such as the Yangtze River Delta, the Beijing–Tianjin–Hebei region, or a single county. However, due to the complexity and diversity of regional types in China, it is necessary to adopt different development policies based on different locational conditions, natural endowments, and economic social development levels to promote the sustainable development of rural areas. There are few studies on changes in the scale, shape, and distribution of rural settlements in China, which has limited our understanding of the overall pattern and regional differences of rural settlements across China from a vertical perspective.

This study used detailed national land use data from satellite imagery interpretation, socioeconomic statistics, and field survey data to reveal the spatio-temporal patterns governing rural settlements in China, from the perspectives of settlement expansion, population agglomeration capacity, shape changes, spatial pattern changes, and the directional characteristics of settlement location choice and to assess the impact of key socioeconomic factors on the evolution of those spatio-temporal patterns. The research took prefecture-level cities or counties directly administered by provinces as the analysis unit, with a total of 361 subjects. It is hoped that this study will contribute to the future revitalization of China’s rural areas and the reconstruction of settlement spaces, as well as serve as a reference for the structural optimization of rural settlements in the course of rapid urbanization in developing countries.

2. Materials and Methods

2.1. Data Sources and Preprocessing

Three types of data were used in this study: (1) Rural settlement spatial data derived from China’s land use remote sensing interpretation data from the Resource and Environment Science and Data Center of the Chinese Academy of Sciences (http://www.resdc.cn/Default.aspx (accessed on 3 July 2021)). This set of data divides land use into six categories and 25 subcategories. Rural settlement land is a subcategory of construction land [28]. (2) Socioeconomic statistics, including on rural permanent population, population over 65 years old, level of urbanization, per capita income of rural residents, agricultural employees, and local fiscal revenue, are from the China Statistical Yearbook (1996–2016) and population sample survey data. (3) Field survey data and materials mainly consist of data obtained by researchers conducting field surveys in typical areas. What we need to explain is that both remote sensing data and social and economic data are uniformly obtained from the national level, and data source standards are consistent to ensure data quality.

Data preprocessing includes: (1) Rural settlement land information extraction. With the support of ArcGIS10.2 software, rural settlement land information was extracted based on remote sensing interpretation data. The extracted rural settlement land information was in a grid format with a spatial resolution of 30 m. (2) Spatialization of statistical data. The sorted social and economic statistical data were associated with the vector spatial data of administrative divisions for the purpose of statistical analysis of rural settlement changes. (3) Sorting typical survey data. The survey materials of typical villages from different regions were collected, and high-resolution remote sensing images of three sample villages were sorted.

2.2. Methods

2.2.1. Rural Settlement Indices

1.

The rural settlement sprawl index (RSI)

RSI is the ratio of the land area of rural settlements at the end of the study period to the land area of rural settlements at the start of the study period. It is used to reflect overall changes in the size of rural settlements. When the RSI is greater than 1, it indicates that the land area of settlements expanded; when the RSI is less than 1, it indicates that the land area of settlements shrank. The specific calculation formula is as follows:

$$\mathrm{RSI}={\mathrm{RSA}}_{\mathrm{ie}}/{\mathrm{RSA}}_{\mathrm{is}}$$

${\mathrm{RSA}}_{\mathrm{ie}}$ and ${\mathrm{RSA}}_{\mathrm{is}}$ are the extent of rural settlement land area in the last year and first year of the study period, respectively.

2.

The rural settlement capacity index (RCI)

RCI reflects changes in the population agglomeration capacity of rural settlements and is a functional indicator of rural settlements. When the RCI is greater than 1, it indicates that the population agglomeration capacity of the area is enhanced, and settlement land use efficiency is improved; when the RCI is less than 1, it indicates that the population agglomeration capacity is reduced, land use efficiency is reduced, and hollowing out is a serious problem. It is calculated as follows:

$$\mathrm{RCI}=\frac{{\mathrm{POP}}_{\mathrm{ie}}}{{\mathrm{RSA}}_{\mathrm{ie}}}/\frac{{\mathrm{POP}}_{\mathrm{is}}}{{\mathrm{RSA}}_{\mathrm{is}}}$$

${\mathrm{POP}}_{\mathrm{ie}}$ and ${\mathrm{POP}}_{\mathrm{is}}$ stand for the total rural population of unit i at the end and start of the research period, respectively.

3.

The landscape shape index (LSI)

LSI is used to characterize changes in the spatial shape of rural settlements. Fragstats v4.2.1 software was used to calculate the landscape index values at the end and the beginning of the study and obtain the dynamic change values [29]. The two indicators of mean shape index (MSI) and mean patch fractal dimension (MPFD) are selected to represent the complexity and the regularity of the landscape shape of settlements, respectively. The higher the value, the greater the interference of human activities on settlement space, the more irregular the shape of the settlement, and the more complex the shape of the settlement [30].

① Mean Shape Index (MSI)

$$\mathrm{MSI}=\frac{{\sum }_{\mathrm{j}=1}^{\mathrm{n}}\frac{{\mathrm{p}}_{\mathrm{j}}}{\sqrt[2]{{\mathrm{na}}_{\mathrm{j}}}}}{\mathrm{n}}$$

${\mathrm{p}}_{\mathrm{j}}=$ perimeter of rural settlement patch j; ${\mathrm{a}}_{\mathrm{i}}=$ area of rural settlement patch; n = number of rural settlement patches.

② Mean Patch Fractal Dimension (MPFD)

$$\mathrm{MPFD}={\displaystyle \sum }_{\mathrm{i}=1}^{\mathrm{m}}{\displaystyle \sum }_{\mathrm{j}=1}^{\mathrm{n}}\left(\frac{2\ln \left(0.25{\mathrm{p}}_{\mathrm{ij}}\right)}{{\mathrm{lna}}_{\mathrm{ij}}}\right)\frac{{\mathrm{a}}_{\mathrm{ij}}}{\mathrm{A}}$$

m = the number of patch types; n = the number of patches of a class; ${\mathrm{p}}_{\mathrm{ij}}=$ the perimeter of patch ij; ${\mathrm{a}}_{\mathrm{ij}}=$ the area of patch ij; A = total landscape area.

4.

The rural settlement distribution change index (RDCI)

The kernel density estimation method is used to measure the density of rural settlement spatial distribution points of neighboring areas to evaluate changes in the spatial distribution of settlements. Based on ArcGIS 10.2, grid calculation of rural settlement area in the late and early stages of the study was carried out. The factor transition point tool was used to extract the central point of th rural settlement patch, and th kernel density tool was used to generate the spatial distribution map of rural settlement kernel density. In the process of estimating the spatial distribution of rural settlements, the density estimation of rural settlements is selected after the area weighting of rural settlements [31].

$${\mathrm{f}}_{\mathrm{n}}\left(\mathrm{x}\right)=\frac{1}{\mathrm{nh}}{\displaystyle \sum }_{\mathrm{i}=1}^{\mathrm{n}}\mathrm{k}\left(\frac{\mathrm{x}-{\mathrm{x}}_{\mathrm{i}}}{\mathrm{h}}\right)$$

wherein $\mathrm{k}\left(\frac{\mathrm{x}-{\mathrm{x}}_{\mathrm{i}}}{\mathrm{h}}\right)$ is the kernel function; h > 0 is the bandwidth or smoothing parameter; n is the number of rural settlement patches; and $\left(\mathrm{x}-{\mathrm{x}}_{\mathrm{i}}\right)$ is the distance from the estimated point to the first known point.

2.2.2. Analysis Model of Socioeconomic Factors Affecting Rural Settlement Change

The transformation and development of the rural economy and rural society are the major factors in changing the spatial pattern of rural settlements. This study assumes that changes in the spatial pattern of rural settlements are primarily affected by the level of rural economic development, the number and structure of the rural permanent population, urbanization level, and the overall level of regional development. (1) The level of rural economic development is consider to be the most direct factor affecting the evolution of settlements. As farmers’ incomes increase, the ability to renew residential housing in rural areas has increased, which has directly led to changes in the scale, shape, and spatial distribution of rural settlements; therefore, this study uses the two indicators of rural residents’ per capita income (INCOME) and the proportion of the population employed in agriculture (EMPLOY) as indicators of this change. (2) Change in settlement space is closely related to the rural population. The size of the rural population affects the size of the settlement space, and the population structure affects the settlement agglomeration capacity and the degree of human interference in settlement space, so the number of permanent rural residents (POP) and proportion of the rural population who are elderly (AGPOP) were selected as the two indicators of this change. (3) Regional overall development level affects the flow direction of urban and rural development elements, which determine the spatial equilibrium state of urban and rural development and inevitably affect the evolving spatial pattern of rural settlements, so the indicators of level of urbanization (URBAN) and local fiscal revenue (REV) have been chosen as the indicators of this change. The level of urbanization refers to the proportion of urban population in the total population. Based on the above analysis, a regression analysis model for analyzing factors that influence rural settlement change was constructed. The model’s formula is as follows:

$$ln{I}_{it}={\alpha }_{it}+{\beta }_{1}lnINCOM{E}_{it}+{\beta }_{2}lnEMPLO{Y}_{it}+{\beta }_{3}lnPO{P}_{it}+{\beta }_{4}lnAGPO{P}_{it}+{\beta }_{5}lnURBA{N}_{it}+{\beta }_{6}lnRE{V}_{it}+{\epsilon }_{it}$$

wherein $ln{I}_{it}$ is the dependent variable, which represents the rural settlement pattern index in year i and region t; $lnINCOME$ is the natural logarithm of the per capita net income of rural residents; $lnEMPLOY$ is the natural logarithm of the proportion of the population employed in agriculture; $lnPOP$ is the natural logarithm of the permanent rural population; $lnAGPOP$ is the natural logarithm of the proportion of the rural population who are elderly; $lnURBAN$ is the natural logarithm of the regional urbanization level; $lnREV$ is the natural logarithm of local fiscal revenue; α and β are the constant terms; ε represents the random error term; and i and t are the observed individual and observation time.

3. Results

3.1. Spatio-Temporal Features of Changes in Rural Settlement Scale

Between 1995 and 2015, the land area of rural settlements in China trended higher. During those two decades, their total area increased by 1,353,800 hectares, accounting for 9.77% of the total rural settlement area. The land area of rural settlements in 321 (88.92%) of the prefectural-level administrative districts in China increased, 114 (31.58%) prefectural-level administrative districts of them had an RSI value greater than 1.25, and 18 prefectural-level administrative districts of them had an RSI value greater than 2, which indicates that the area of rural settlements increased significantly. The RSI value results have the obvious feature of being “high in the west and low in the east” (Figure 1). Using the Hu Line (Population Density Contrast Line) as a boundary, we can see that RSI values in the area west of the line, which have an average value of over 1.25, are significantly higher than values in the area east of it, which are generally low, as there has been more migration to the big cities. Specifically, the area of many rural settlements in northeast China shrank, and the area of rural settlements in hilly and mountainous areas, such as Hunan, Jiangxi, and Guangxi provinces, remained basically stable but shrank in some areas. The RSI scores of cities in the Beijing–Tianjin–Hebei region and the Yangtze River Delta were higher than in their surrounding areas. Due to greater demand from residents in western China for better living conditions, RSI value increased significantly, with some areas having value greater than 2. Moreover, western China is a concentrated residential area of ethnic minorities, and the population policy to encourage fertility is also a factor that cannot be ignored to promote the expansion of rural settlements.

3.2. Spatio-Temporal Features of Changes in Rural Settlement Capacity

As China’s population has urbanized, the ability of rural settlements to attract people has generally weakened. For the period 1995–2015, 326 (90.30%) prefectural-level administrative districts had a rural settlement capacity index (RCI) value below 1, and 167 (46.26%) prefectural-level administrative districts of them had an RCI value of less than 0.75. Despite increases in the land area of rural settlements, the permanent rural population rapidly decreased, resulting in a decline in the ability of rural settlements to retain people. Areas with high RCI values were mainly concentrated in South China. With the advancement of the Great Western Development Strategy and the implementation of nomadic settlement projects, the settlement capacity of western provinces, such as Xinjiang, Qinghai, and Tibet, was enhanced. In the northeast region, which is an important agricultural production base, the rural population fell but by less than in other regions, while the land area of rural settlements expanded only slightly or even shrank in the two decades, which resulted in slightly higher RCI values (Figure 2).

3.3. Changes in Rural Settlement Landscape Shape Metrics

This study uses the ratio of the mean shape index (MSI) and mean patch fractal dimension (MPFD) of rural settlements at the start and end of the study period to identify changes in the spatial morphology of settlements (Figure 3). The results show that between 1995 and 2015, the MSI and MPFD of China’s rural settlement showed an overall upward trend, especially in the inland northwest region, in the Yellow River basin, and the Yangtze River Delta. This shows that human interference in rural settlements gradually increased, and the shape of rural settlements became more complex and irregular.

Since the mid-1990s, due to the urgent need to improve housing in rural China and the lack of residential planning rules, rural house building has been disorderly. Some villagers have built houses along roads and rivers to facilitate transportation, and some have built houses on farmland (Figure 4). As a result, the spatial morphology of rural settlements has changed significantly, and the shape of settlements has become increasingly irregular.

3.4. Changes in Rural Settlement Kernel Density

ArcGIS Version 10.2 software was used to subtract the Chinese rural settlement kernel density values from 2015 to 1995 in order to reveal the dynamically changing spatial distribution of kernel density for the two-decade study period (Figure 5). The result shows that changes in the spatial distribution of Chinese rural settlements stabilized overall and that kernel density values were between 0.00/km² and 0.05/km². Declines in rural settlement density were mainly seen in the northeast and southeast of the country, where the scale and scope of vanishing rural settlement patches were greater, and the largest fall in density was to 0.25/km².

Rural settlements in the Beijing–Tianjin–Hebei region and in the Yangtze River Delta maintained their growth and expansion, forming a core area with high density values within the range of 0.15–0.48/km². In addition, with the in-depth development of regional development strategies, such as the Great Western Development Strategy and the Rise of Central China, there has been rapid economic and social development in central and western China, infrastructure including urban and rural transportation, hydropower, and telecommunications as well as public service facilities has been built, and technological advances continue to weaken restrictions on the growth of rural settlements set by natural factors of production. The desire of residents in rural areas to improve their residential conditions led to the agglomeration and expansion of rural settlements in western China. In the contiguous areas of Ningxia, central Shaanxi, and Gansu Province as well as the Sichuan Basin, there were multiple core areas with small increases in settlement density. The kernel density of the settlements increased in the range of 0.05–0.35/km².

3.5. Directional Characteristics of Rural Settlement Location Choice

Terrain conditions can determine the space for the formation and development of rural settlements, and they can also limit the scope of their expansion [32]. Rural settlements tend to be located on flat or gently sloping terrain. As height and slope increase, the land area of rural settlements gradually declines (

Table 1. Directional characteristics of rural settlement distribution changes in China 1995–2015.

Name	Scope	1995 (104 hm2)	2015 (104 hm2)	Value (104 hm2)
Height	≤200 m	890.75	975.26	84.51
	200–500 m	148.99	162.74	13.75
	500–1000 m	74.17	85.48	11.31
	>1000 m	136.03	161.85	25.81
Slope	≤3°	1145.09	1263.32	118.23
	3–7°	72.17	82.76	10.59
	7–15°	27.53	32.66	5.13
	>15°	5.16	6.59	1.43
Distance from major rivers	≤20 km	404.39	444.22	39.83
	20–30 km	449.40	510.28	60.88
	30–50 km	197.03	212.17	15.14
	>50 km	199.13	218.66	19.53
Distance from major transports lines	≤5 km	625.71	716.79	91.08
	5–8 km	193.03	208.09	15.06
	8–10 km	88.35	94.66	6.30
	>10 km	342.85	365.79	22.94

). In 2015, 82.15% of rural settlements areas were located below 500 m above sea level, and 70.4% of them were below 200 m. A total of 91.19% of rural settlements areas are located on terrain with a slope of less than 3°, and few are in areas with slope above 15°. Looking at how things changed between 1995 and 2015, most rural settlements were located on low-altitude (an elevation below 200 m), low-slope (less than 3° slope) terrain. The area of settlements at an elevation below 200 m increased by 84.51 × 10⁴ hm², and the area of settlements on a slope of less than 3° increased by 118.23 × 10⁴ hm², which accounted for 62.42% and 87.33% of the increase in land area of rural settlements, respectively. In addition, due to growth in demand for rural housing in western China, there was a slight increase in housing in high altitude zones.

Water source conditions relate to both consumption by humans and livestock, and they affect agricultural irrigation and industrial production, so 68.91% of rural settlements in China are within 30 km of the mainstem of a river. In the period 1995–2015, the land area of rural settlements within 30 km of the mainstem of a river increased by 100.71 × 10⁴ hm², accounting for 74.39% of the total area increased of rural settlements. In addition, transport location is a key element that determines the distribution of settlement spaces. To reduce the cost of housebuilding and facilitate rapid travel, rural residents generally choose to build new homes on the side of arterial roads or roads connected to arterial roads. Indeed, 66.76% of rural settlements areas are within 8 km of an arterial road, and the half of them are within 5 km. In the 20-year study period, there was rapid growth of rural settlement land area very close to major transportation lines and rivers, reflecting the strengthening directional characteristics of spatial distribution of rural settlements being near water and near roads.

3.6. Analysis of Factors Influencing Rural Settlement Change

Natural factors deeply influence the initial structure and pattern of rural settlements, while socioeconomic factors are the main factors that drive the spatio-temporal pattern evolution of rural settlements [33]. We used model regression analysis to identify the factors that influenced the spatio-temporal evolution of China’s rural settlements from 1995 to 2015. The random effects model and fixed effects model were used to analyze socioeconomic factors. The model was tested using the chi-square test from the Hausman random effect model (Sig.), with a p value of less than 0.05 indicating rejection of a random effect at a confidence level of 0.05, so a fixed effects model was selected(

Table 2. Relationships between rural settlement landscape metrics and explanatory variables.

Independent Variable	Dependent Variable
	RSI	RCI	MSI	MPFD	KD
LNINCOME	0.1885 *	−0.1898 ***	0.0010	0.0002	0.0028
LNEMPOLY	−0.2327	0.1507 **	−0.0171 ***	−0.0015 *	0.0142 ***
LNPOP	0.2492 *	0.8963 ***	0.0133 ***	0.0016 **	−0.0123 ***
LNAGPOP	0.0450	0.3550 ***	0.0048	0.0008	−0.0051
LNURBAN	0.3830 **	−0.0309	−0.0005	0.0001	0.0025
LNREV	−0.1065 *	0.1177 ***	0.0034 *	0.0003	−0.0005
Constant	−1.3896	−3.9984 ***	0.9214 ***	0.9893 ***	0.2141 ***
R2	0.11	0.68	0.22	0.13	0.12
F test	1.06	3.80	1.01	1.01	397.01

Note: * indicates significance at the 10% level; ** indicates significance at the 5% level; *** indicates significance at the 1% level.

).

Income of rural residents is the most fundamental motivation for the evolution of settlements. As income increases, people have more ability and more desire to renovate, expand, or build houses to improve their living environment. Similarly, people engaged in agricultural production generally stay in rural areas, and the higher the proportion of people employed in agriculture, the higher a village’s settlement capacity and density. However, agriculture is a basic industry; compared with people who work in manufacturing or services, agricultural employees have lower incomes, so there are fewer economic and social activities in rural areas, and the ability of rural settlements to transform themselves is weak. As a result, the higher the proportion of people employed in agriculture, the smaller the change in rural settlement pattern.

The rural population is what makes a settlement, and people’s various economic and social activities directly affect rural settlement space. Naturally, there was a correlation between the size of the rural resident population and the scale of the rural settlement, the pattern of the landscape, and the density of residential areas, all of which passed significance tests at 10%, 5%, and 1%. An increase in the number of permanent rural residents means greater demand for housing, but in the process of expanding in settlement scale and increasing settlement capacity, some adjacent villages expand into each other, forming large residential areas. In addition, some areas are involved in village relocation and amalgamation programs, so small settlements are disappearing, and the total number of settlements is decreasing. This is also greatly changing the pattern of settlement spaces. Since an aging population is less likely to improve living space and participate in economic and social activities, it has less of an impact on the scale and landscape of a rural settlement. Therefore, an increase in the proportion of the rural population that is elderly significantly increases settlement agglomeration capacity, but it has no significant correlation with the rural settlement sprawl index, landscape shape index, or kernel density.

With the rapid deruralization of the population in China, the urbanization level has increased significantly, and it is common knowledge that the size of urban landscapes has gradually expanded [34,35,36]. The statistical results of this study show that in the course of rapid urbanization, the scale of rural settlements also increased. The reason for this may be China’s dual system for urban and rural residents in the past, whereby the household registration system restricted people from the countryside settling in cities and meant they were not entitled to equal access to education, medical care, and other public services. Many migrant workers, therefore, are still “amphibious” residents who need to maintain or renovate their rural homes for the sake of their children’s education and to look after their parents, leading to the expansion of rural settlements. In addition, an increase in local fiscal revenue increased local government intervention in rural areas, resulting in more complex rural settlements. Local fiscal revenue has a significant negative correlation with the rural settlement sprawl index, indicating that as local economic strength grew, fiscal investment was skewed toward rural areas. Governments invested in land consolidation and improvements to rural communities to enhance the living environment and improve quality of life, which attracted people to live in the countryside and improved the population agglomeration capacity of rural settlements.

4. Discussion

In the course of rapid urbanization in China, the core factors involved in rural development have undergone drastic changes, such as population size, land type, and industrial structure, and unbalanced urban and rural development and rural underdevelopment have come to the fore [33,37]. Changes in rural settlement patterns have also become a widespread phenomenon. A large influx of rural residents into cities brought about a rapid expansion in land used for urban construction [36]. Despite a decrease in the rural population, thousands of small villages gradually were abandoned or disappeared, while large villages expanded outward along rivers or roads, and the overall land area of rural settlements grew continuously [38].

Regional development occurs in stages. Under the influence of a variety of the spatial driving forces, residents of different socio-spatial classes have great differences in choosing settlement sites [39]. There is no denying that the development imbalance between China’s east and west has long existed. Unlike the rapid economic and social development of the eastern region, the development of the central and western regions has been slow, and there is still a need to improve housing conditions. The increase in rural settlement area has helped to improve the living conditions and quality of life of individual residents, but it will also have created problems [40]. One such problem is the inefficient use of land resources, which hinders agglomeration and two-way flows of rural core factors of development, affects the integration of primary, secondary, and tertiary industries in rural areas, and further affects the income level of farmers. Another problem is the increased cost of building rural public service facilities and infrastructure construction, which is not conducive to improving the overall environment of rural human settlements. A third problem created by the sprawl of rural settlements is that it leads to significant changes in the spatial pattern of rural settlements, mainly manifested in the decentralization of living space, disorder of production space, and contamination of ecological space [41].

Due to the implementation of dual urban–rural systems and the land use system in China, as well as the lack of substantive village planning mechanisms, the expansion of land area of rural settlements has been disorderly and unrestricted, the hollowing out of rural areas has been exacerbated, and conflict over land used for construction in urban and rural areas has increased [42,43]. China has many people and limited land, so land resources, which are an important factor of production, are extremely precious. However, the decentralized and disorderly expansion of rural settlements has led to issues such as environmental degradation [40]. The land consolidation mode with a single factor and single means makes it difficult to solve the rural decay under the background of rapid urbanization and agricultural modernization. As a result, relying on the current situation of the spatial distribution of rural settlements in the new era, the integration of various factors, clear multiple goals, and the adoption of a variety of ways to promote comprehensive land improvement can improve the efficiency of land use and sustainable development capacity of rural areas [44].

In the next 10–20 years, as China’s industrialization and urbanization continue, the migration of rural residents to cities will still be a major trend of population flows, which will inevitably lead to further evolution and development of rural settlement patterns. The following are the future trends of rural settlements in China: first, in pursuit of a more convenient, comfortable, and safe living environment, the land area of rural settlements in mountainous and hilly areas will decline; second, based on a reliance on the development foundations of traditional agricultural areas and their resource and environment carrying capacities, rural settlements in plain areas will become more intensive; and third, lessons will be learned from the counter-urbanization experienced by developed countries [45], and the land area of rural settlements near developed cities, such as Beijing and Shanghai, will continue to increase.

To more efficiently utilize land resources and enhance the living environment in rural areas, it is necessary to take the following measures with regard to the rational layout of rural settlements. First, governments needs to accurately grasp changing trends in the scale and structure of the rural population; make urban and rural development plans that fully consider the lifestyles, production methods, and living environments of rural residents; and carry out substantive village planning to improve infrastructure and service facilities in rural areas. The second measure concerns policies and systems. To achieve the objective of sustainable use of land resources, it is vital to promote the reform of the rural land use system, establish a multi-tier land use policy system, reform and renew the household registration system, guarantee that rural residents have equal rights to public services, and ensure that people from rural areas who wish to migrate to cities can enter urban areas and stay there. Finally, it is feasible for China to learn from the successful experiences of other countries in rural construction and development, such as “key settlements” in the United Kingdom, and implement diverse development policies for different classifications of villages.

5. Conclusions

This study used rural settlement land area indexes, a landscape shape index, kernel density analysis, and a fixed-effect model to determine the spatio-temporal evolution of rural settlements in China and their influencing factors. The results of this study show that the land area of rural settlements in China increased by 1.35 million hectares from 1995 to 2015, with 88.92% of prefecture-level administrative units seeing an increase in rural settlement area, which was basically consistent with the development trend of rural settlements in western European countries in the mid-20th century [9,10]. Regionally, the expansion in rural settlement area was mainly concentrated in central and western China, which verifies the previous studies on regional rural settlements, such as the Qinghai-Tibet Plateau region and the loess hilly and gully region. The ability of rural settlements to attract residents has weakened, with 90.30% of administrative units experiencing a decline in the population per unit of rural settlement area.

During the study period, the spatial shape of rural settlements became more complex and irregular, settlement landscapes became more fragmented and decentralized, and spatial heterogeneity increased. The directional characteristics of changes in settlement location indicate that settlements have tended to expand into patches of low-lying, flat, and gently sloping land that are increasingly close to arterial roads and mainstem rivers. The change in the scale of the land area of rural settlements was affected by many factors, including the level of rural economic development, the size and structure of the rural population, and regional development capacity. Changes in the shape of settlements and in settlement kernel density were closely linked to factors such as the number of permanent rural residents, the proportion of the population employed in agriculture, and local fiscal revenue.

The key to optimizing the spatial layout of rural settlements is scientific planning and zoning implementation. The spatial distribution of rural settlements in southeast China is seriously decentralized, so it is necessary to coordinate the development space of rural industries and promote the integrated development of urban and rural areas. Northeast China and other regions are traditional agricultural intensive planting areas, with large per capita rural settlement area and serious hollowing out of the countryside. Our top priority is to solve the problem of “hollow villages” and improve the rural living environment. In addition, it is urgent to deal with the relationship between land use and ecological environment protection and rationally plan new rural settlements in northwest China. Understanding spatial differences between rural settlements in China, identifying the key factors that determine the spatial layout of settlements, and making decisions concerning rural development by region and type are of great importance for promoting the comprehensive revitalization of rural areas.