A Quantitative Method for Characterizing the Spatial Layout Features of Ethnic Minority Rural Settlements in Southern China

Abstract

The site selection and spatial arrangement of rural settlements embody the ethnic characteristics and cultural heritage of ethnic minority groups. Investigating their spatial layout features and underlying determinants can provide both theoretical foundations and practical methodologies for the conservation and development planning of these settlements. This paper takes the representative ethnic minority villages in the first batch of key traditional villages in Liuzhou, Guangxi, as the example, and employs a combination of qualitative and quantitative methods to study the spatial layout characteristics of ethnic minority villages in southern China. This study utilizes GIS-based analytical methods to calculate quantitative indicators based on planar graphs and digital elevation model (DEM) of ethnic minority settlements. The research results show that the spatial distribution of ethnic minority villages in southern China is closely correlated with natural geographical conditions. To be specific, ethnic minority villages in southern China generally distribute in accordance with the terrain and form specific spatial relationships with roads, topography, mountains, and water. Regardless of whether minority residents live on mountain tops or in valleys, they generally prefer gently sloping terrain. In addition, factors such as natural environment (sunshine and water sources, etc.) and traffic conditions are considered comprehensively in the settlement location. On this basis, the spatial layout features of rural settlement are extracted, and corresponding characteristic maps are constructed. The construction framework of the spatial characteristics map established based on “overall layout, architecture, roads and architecture-natural pattern” in this paper can be applied to general rural settlements. The findings can provide both theoretical foundations and practical references for the planning and development of rural settlements across different regions and ethnic groups.

1. Introduction

The culture of ethnic minorities is an indispensable part of traditional Chinese culture. An in-depth understanding and systematic study of China’s ethnic minority characteristics and culture holds significant value for both strengthening the consciousness of a Chinese national community and enhancing cultural identity. Furthermore, it also has significant value for the inheritance and promotion of global ethnic culture. As a place of living and continuous development of ethnic minorities, rural settlements reflect the ethnic characteristics and cultural heritage of ethnic minorities from the aspects of location layout, settlement environment, structural morphology, and residential buildings. Guangxi is a typical multi-ethnic convergence zone in southern China, in which the number of ethnic minorities is large, and the ethnic distribution is wide. At the same time, the terrain and geomorphology of Guangxi are unique, and a great number of mountains, valleys and plains distribute widely. And this phenomenon is well reflected in the widely circulated folk proverb in Guangxi: “High mountains for the Yao, low hills for the Miao, plains for the Han, valleys for the Zhuang and Dong”.

The existing research on rural settlements can be roughly divided into two major categories: one concentrates on the harmonious coexistence between rural settlements and the humanistic and natural environment, as well as exploring the preservation and sustainable development of these settlements [1,2,3], while the other focuses on the spatial layout and morphological features of rural settlements. Urbanization has a certain degree of impact on the landscapes of traditional villages. The protection of traditional villages primarily focuses on cultural heritage and settlement landscapes, and a protecting methodology has been developed [4]. Sustainable integration of rural settlements into metropolises is one of the most challenging issues in the global south, and urban maps have been applied to put forward a typology of villages-in-the-city [5]. Regarding the integration and resistance between local and foreign cultures, one viable approach is to study the origins of an ethnic group within the landscapes along natural boundaries (such as mountains and rivers), as well as analyzing the relationship between settlements and adjacent cultural core zones [6]. In the evolutionary development of rural settlement boundaries, some researchers integrate Lefebvre’s theory of space production with the local border perspective to investigate the dynamic impacts of social development on space patterns [7].

In the study of spatial layout for settlement, researchers predominantly analyze the distribution characteristics of settlements and their relationship with the natural environment. The research methods can be broadly categorized into qualitative and quantitative approaches. Quantitative approaches include GIS technology [8,9,10,11], space syntax [12], and statistical methods [13]. Most existing literature focuses on macro-level analysis at the county scale or larger, conducting quantitative characterizations based on inter-settlement distances and spatial relationships. The factors influencing settlement distribution include both natural factors (such as elevation, slope gradient, water sources, sunlight and land [14,15,16,17]) and socio-cultural factors (including population, ethnic composition, transportation, economic level, and farming practices [18,19,20,21,22]). Regarding the formation and evolution of rural settlement patterns, a series of studies have also been conducted [23,24]. Many of these studies focus on the transformation processes of rural areas [25,26,27,28], the architectural characteristics of settlements [29], and the landscape features of rural settlements [30].

It is more intuitive to apply visualization or graphical methods to study the characteristics and relations of the settlements. For example, academician Chang Qing proposed to carry out genealogical research on vernacular architecture, which can specifically study the types of rural houses, architectural structures, construction techniques, etc. [31]. This method not only expresses the basic characteristics and distribution rules of rural architecture, but also provides the comparison of different settlement forms and residential characteristics. In addition, landscape genes have the theoretical guidance value for the expression of spatial layout characteristics and genetic patterns [32,33], and landscape genetic map also reflects the logic and order of landscape genes in settlements [34,35,36]. Later, many scholars have successively established landscape genetic maps including geographical features, spatial distribution, and settlement heritage [37,38,39], which can not only analyze the characteristics and laws of settlement landscapes [40], but also understand the inter-relationships between landscape features and the culture and geography of village [41]. Among these studies, quantitative research methods provide a fixed way and process for the construction of genetic maps [30,40,41,42].

On the basis of current research, this paper selects 10 representative traditional settlements in Liuzhou, Guangxi, analyzing the spatial layout characteristics from the perspective of each settlement. This paper applies the GIS analysis method to quantitatively study the characteristics in terms of geographic elements, location layout, and spatial structure for ethnic minority rural settlements, and construct the corresponding characteristics maps. This research method can provide a theoretical basis for the future development planning of settlements and can also be extended to horizontal comparisons of ethnic minority settlements across different ethnic groups and regions in the future. Through the spatial characteristic maps of ethnic minority rural settlements constructed in this study, we can understand the ethnic characteristics and cultural connotations of ethnic minorities, offering practical approaches for the planning and development of rural settlements in other ethnic groups.

2. Materials and Methods

The spatial layout characteristics map of rural settlements reflects the regularity and logic of their distribution within geographic space, and is a product of the interdependence between humans and nature. The essence of constructing characteristics maps is to excavate the elements which can best represent the settlement’s spatial distribution characteristics and analyze their relations with nature, nation, and culture. In addition, various internal and external influence factors are also considered, and then the characteristics and links are expressed as diagrams. The construction of the map can facilitate researchers to make horizontal and vertical comparisons in order to study the differences and connections between different rural settlements so they can have an overall and intuitive grasp of the spatial characteristics of settlements within the study area.

2.1. GIS Characterization of Spatial Elements for Rural Settlements

In the previous study [1], the planar quantitative method has already analyzed and summarized the planar morphological characteristics of rural settlements, but it is impossible to describe the spatial layout and elevation features; it is also difficult to directly analyze the causes of the planar morphological features, so it is necessary to introduce the three-dimensional spatial quantitative method. The study of three-dimensional spatial layout characteristics of ethnic minority rural settlements requires geographical characteristics of the settlement, and GIS technology integrates relatively complete geographic information, so it can be applied to calculate the geographic environment of ethnic minority rural settlements in Guangxi. Based on the calculation results, the spatial layout characteristics can be refined, summarized, and classified to analyze the formation causes of the spatial patterns and the ethnic culture embedded in them. At the same time, it is also possible to construct the characteristics map of the spatial layout of ethnic minority rural settlements based on the GIS calculation results.

This paper applies ArcGIS10.2 software to analyze the spatial characteristics of ethnic minority rural settlements. The specific natural environment includes topography, elevation, mountains, rivers, etc., and the most important geographic elements that can reflect the features of the settlement environment are the elevation and the surface topography characteristics derived from it. According to the relevant concepts in geography, the contour line, slope gradient, and the degree of surface undulation have a clear pointing significance in describing the natural geographic features. Thus, the analysis indexes used in this paper include elevation, slope gradient, slope direction, ground fluctuation, and ground roughness, and the specific index definitions and calculation methods are shown in Table 1.

Table 1. Calculation methods and meanings of GIS quantitative indicators.

Index	Formula	Symbol Description	Meaning
Elevation	H	H is the height of Earth’s surface or altitude.	GIS elevation data is a digital model, which represents the height information of the earth surface in digital form.
Slope gradient	$\begin{array}{l}{S}_d=\\ \mathrm{a}\mathrm{t}\mathrm{a}\mathrm{n}\left(\sqrt{{(\mathrm{d}z/\mathrm{d}x)}^2+{(\mathrm{d}z/\mathrm{d}y)}^2}\right)\\ \times 57.29578\end{array}$	dz is the distance change in the height direction, dx is the distance change in the x-direction, dy is the distance change in the y-direction.	For each pixel, calculating the maximum variation rate in the direction from the pixel to its adjacent pixel.
Slope direction	$\begin{array}{l}{A}_s=57.29578\times \\ \mathrm{a}\mathrm{t}\mathrm{a}{\mathrm{n}}^2\left(\mathrm{d}z/\mathrm{d}y-\mathrm{d}z/\mathrm{d}x\right)\end{array}$	dz is the distance change in the height direction, dx is the distance change in the x-direction, dy is the distance change in the y-direction.	It is used to identify the downhill direction with the largest variation rate in the direction from each pixel to its adjacent pixel.
Ground fluctuation	$R_{Fi}=H_{\max }-H_{\min }$	$R_{Fi}$ $\mathrm{is}\mathrm{ground}\mathrm{fluctuation},H_{\max }$ $\mathrm{is}\mathrm{the}\mathrm{maximum}\mathrm{elevation}\mathrm{value}\mathrm{in}\mathrm{the}\mathrm{analysis}\mathrm{window},H_{\min }$ is the minimum elevation value.	It refers to the difference between the highest altitude and the lowest altitude in a specific area, and it is a macroscopic index to describe the topographic characteristics of a region.
Ground roughness	$\begin{array}{l}R={\displaystyle \frac{S_{curve}}{S_{hori}}}\\ \approx {\displaystyle \frac{1}{\cos (S\times 3.14159/180)}}\end{array}$	$S_{curve}$$\mathrm{is}\mathrm{the}\mathrm{surface}\mathrm{area}\mathrm{of}\mathrm{the}\mathrm{ground},S_{hori}$ is the projected area of the ground on the horizontal plane and S is the slope factor (in degree) in the DEM file.	It is the ratio of the Earth’s surface area to its projected area on the horizontal plane in a specific area, and it is a macroscopic index of surface shape.

2.2. Construction Logic of Spatial Layout Characteristics Map for Rural Settlement Based on GIS

This paper constructs maps of layout characteristics for rural settlements from both planar and spatial perspectives. The planar features focus on the shape, boundaries, and overall distribution patterns of the settlements, while the spatial characteristics emphasize the positional relationships between residential buildings and topographic features such as landforms, mountains, and rivers. In terms of spatial layout features, this paper employs GIS analysis methods to calculate the indicators listed in Table 1. Based on the quantitative results, the types and manifestations of settlement layout characteristics are summarized. Thus, the spatial layout characteristic maps of representative settlements can be established. Based on the existing research on planar morphological characteristics [43], the framework for constructing the characteristic map and the research approach of this paper are illustrated in Figure 1:

Figure 1. Construction framework of the spatial layout characteristics map for rural settlements based on planar quantitative methods and GIS technology.

3. Spatial Distribution Characteristics of Ethnic Minority Rural Settlements in Southern China

3.1. Case Selection

This paper takes the ethnic minority rural settlements in Liuzhou, Guangxi as the example to explore the general characteristics of the spatial distribution for ethnic minority villages in south of China. Liuzhou is located in the north-central region of Guangxi Zhuang Autonomous Region. There is a large number of ethnic minorities living in the mountainous and hilly areas of Guangxi, specifically the Han, Zhuang, Miao, Dong, etc. The cultural characteristics of various ethnic groups are very significant, the differences between them are also relatively obvious, and the regionality has a very significant impact on the spatial layout characteristics of rural settlements. This paper takes ten traditional villages in Rong’an County, Rongshui Miao Autonomous County and Sanjiang Dong Autonomous County in Liuzhou, Guangxi Zhuang Autonomous Region, as the study cases, which are also representative of the first group of key traditional villages in Liuzhou, Guangxi. The specific ethnic groups contain Han, Zhuang, Miao, and Dong, as shown in Table 2, and their location in Liuzhou is shown in Figure 2:

Table 2. Selection and distribution of representative villages.

County	Village Name
Rong’an County	Tongban Tun (Han), Longmiao Tun (Zhuang), Dapao Tun (Miao), Xigupo Tun (Zhuang)
Rongshui Miao Autonomous County	Gandong Tun (Miao), Guoli Tun (Miao), Songmei Tun (Miao), Pingmao Tun (Dong)
Sanjiang Dong Autonomous County	Gaoding Village (Dong), Gaoyou Village (Dong)

Figure 2. Schematic distribution of rural settlements in Liuzhou.

3.2. Calculation Results of GIS-Based Spatial Features of Rural Settlements

In this section, we use ArcGIS 10.2 software to extract contour lines and calculate slope gradient, slope direction, ground fluctuation, and ground roughness from the DEM elevation data files (resolution of 12.5 m) of each rural settlement in Figure 2, and then integrate and analyze the spatial distribution characteristic elements of the rural settlements. First of all, we take Gandong Tun in Liuzhou as an example and apply ArcGIS to carry out quantitative calculations according to the definition and physical meaning of the quantitative indicators in Table 1. After calculations and data processing, the calculation results of Gandong Tun are shown in Table 3:

Table 3. Calculation results of Gandong Tun based on GIS indicators.

Village Map	Elevation Data	Slope Gradient
Slope direction	Ground fluctuation	Ground roughness

Similarly, the same indicator calculation and cloud map drawing are carried out for the other nine villages in Table 2. Based on the GIS calculation results for the ten traditional villages, which are extracted and integrated, we can summarize the variation range and representative value of each indicator in each village according to the spatial distribution of each indicator in the villages. Furthermore, we can also summarize them to provide theoretical and numerical bases for horizontal and vertical comparisons between villages, and here the study area is still defined according to three counties, as shown in Table 4, Table 5 and Table 6:

Table 4. Spatial structural characteristics of villages in Rong’an County based on GIS.

Village Name	Tongban Tun (Han)	Longmiao Tun (Zhuang)	Xigupo Tun (Zhuang)	Dapao Tun (Miao)
Village map
Elevation (meter)	355–430	130–150	150–160	90–150
Slope gradient (degree)	11–27	6–17	0–17	0–22
Slope direction	South, Southwest	West, Northwest	South, Southeast	East, West
Ground fluctuation (meter)	25–90	0–25	0–25	5–35
Ground roughness	1–1.2	1–1.06	1.03–1.1	1–1.09

Table 5. Spatial structural characteristics of villages in Rongshui Miao Autonomous County based on GIS.

Village Name	Gandong Tun (Miao)	Guoli Tun (Miao)	Songmei Tun (Miao)	Pingmao Tun (Dong)
Village map
Elevation (meter)	460–480	560–640	750–850	150–190
Slope gradient (degree)	0–17	0–22	0–27	0–27
Slope direction	Northwest, East, Northeast	East, Southeast, Northeast	South, Southeast, Southwest	East, Southeast, Northwest
Ground fluctuation (meter)	5–50	16–70	16–90	16–70
Ground roughness	1–1.06	1–1.2	1.0–1.2	1–1.11

Table 6. Spatial structural characteristics of villages in Sanjiang Dong Autonomous County based on GIS.

Village Name	Gaoding Village (Dong)	Gaoyou Village (Dong)
Village map
Elevation (meter)	450–550	490–540
Slope gradient (degree)	0–17	0–30
Slope direction	Northwest, East, Northeast	East, Southeast, North, Northwest
Ground fluctuation (meter)	16–70	16–50
Ground roughness	1–1.06	1–1.11

3.3. Analysis of the Relationship Between the Spatial Layout Characteristics and Natural Environment

The widely circulated folk proverb vividly reflects the distinctive ethnic characteristics in settlement spatial distribution in Guangxi: “High mountains for the Yao, low hills for the Miao, plains for the Han, valleys for the Zhuang and Dong”. Ethnic minorities in Guangxi engaged in prolonged competition with the Han over natural resources and environments, yet found themselves at a disadvantage, ultimately being relegated to mountainous terrain. Among these minorities, as the most populous indigenous group, the Zhuang predominantly settled at mountain bases. Migrant groups that migrated into the region, such as the Miao and Yao people, typically settled at mountainside and mountaintop, respectively. The Dong people are primarily distributed in Sanjiang Dong Autonomous County and Longsheng County. These areas boast abundant natural resources and convenient transportation along waterways, and are situated between mountains and rivers. The Dong settlements typically exhibit substantial scale, ranging from larger villages of approximately 100 households to smaller hamlets comprising 50–60 households. The distinct topographic distribution characteristics of ethnic minority settlements provide typological references and evidential foundations for the subsequent map construction in this study.

3.3.1. Terrain and Geomorphology

Topography is an important aspect of the natural environment of rural settlements, and each village has a specific topography. Plateaus, mountains, hills, plains and basins are the most common five types of terrain, but in Guangxi, mountains, hills and plains are more obvious. According to the calculated data, Rongshui Miao Autonomous County and Sanjiang Dong Autonomous County are located in mountainous areas, while most regions of Rong’an County are hilly areas. The layout of residential buildings is closely related to the topography. Taking Songmei Tun and Guoli Tun in Table 5 as an example, most of the residential buildings are built on the top of the mountain, the orientation of each household is not completely toward south, and the house layout in the villages is more in line with the direction of the contour line, so the distribution trend of the residential buildings in the villages are the products influenced by terrain factors.

3.3.2. Slope and Slope Direction

According to the results in Table 4, Table 5 and Table 6, it can be concluded that in the 10 traditional villages listed in this paper, the slope is mostly concentrated in the range of 0–25 degrees, the mountainous areas where the villages are located generally have relatively obvious slopes, and there are very few completely horizontal areas. Moreover, in the village distribution area, the slope of the village location is the lowest compared with other locations. Regardless of the region, the slope direction of the residential houses is relatively scattered, and villagers do not completely choose to settle on the hillside facing the south; on the contrary, they settle in all directions, with no clear pattern of concentration. Regardless of the orientation of the mountain slope, villagers generally choose to settle their residential buildings on the hillside, and the buildings also present specific variations with the change in slope.

3.3.3. Ground Fluctuation and Ground Roughness

Ground roughness is a quantitative index reflecting the degree of surface undulation and erosion, with a low roughness indicating that the undulation of the surface is low and smooth. According to the results in Table 4, Table 5 and Table 6, it can be seen that the roughness values for the 10 traditional villages listed in this paper are all very low, and the residential buildings are distributed in the areas with low roughness, which shows that the ethnic minority villages in Liuzhou generally choose the areas with flatter and smoother terrain. The ground roughness of Tongban Tun, Guoli Tun, and Songmei Tun is higher, reaching a maximum value of 1.2. The highest roughness value for the rest of the villages is near 1.1, but it has not changed in essence, so there is no significant difference in the spatial characteristics of the villages from the perspective of roughness. Table 4, Table 5 and Table 6 show that the ground fluctuation of four villages in Rong’an County is low, being slightly higher in two villages in Sanjiang Dong Autonomous County, while the ground fluctuation of four villages in Rongshui Miao Autonomous County is the highest, which also coincides with the topographic features of the three counties. Compared with the specific elevation value of each village, the ground fluctuation is not directly related to it. In addition, the location of residential buildings also has the lowest fluctuation in each village, so the villagers generally choose the position with the flattest ground to construct their residential buildings.

3.3.4. Rivers and Lakes

Water is an indispensable natural resource for the development of villages, so rivers and lakes have a significant influence on the layout and morphological characteristics of villages. For Dapao Tun and Pingmao Tun, rivers play important roles in the village, serving not only as water sources, but also as tourism resources; therefore, the layouts of the villages are centered around rivers and lakes. In those villages which are close to water sources, dwellings are usually built next to rivers or lakes for the convenience of fetching water. After the analysis, we found that most of the typical ethnic minorities in Liuzhou would choose to build villages close to water sources, except for a few villages (Guoli Tun, Songmei Tun, Gaoding Village, and Gaoyou Village) that were built on high mountains.

4. The Construction of Spatial Layout Characteristics Map for Ethnic Minority Rural Settlements

This section focuses on the spatial layout characteristics of ethnic minority rural settlements in southern China, in order to make up for the shortcomings of the previous two-dimensional planar studies. So, the construction of spatial layout characteristics maps focuses on its three-dimensional features, and the spatial relationship between residential buildings, roads, mountains, and rivers in rural settlements can be analyzed from the perspective of overlooking and elevation. In this way, we can then combine the calculation results of the specific indexes and the clear geographic information to classify the map category in detail, which mainly includes the map of “architectural spatial layout”, “road structure”, and “architecture-nature pattern”.

4.1. “Architectural Spatial Layout” Map of Villages

Firstly, based on the spatial layout of the residential buildings in the village, the corresponding characteristic map is established. Although this paper applies the GIS method to quantitatively calculate and study the characteristics of the topography and geomorphology of the villages, some aspects of the characteristics can still be obtained through qualitative methods. Now, we investigate the distribution of residential buildings in the 10 villages, including the overall layout and the arrangement of buildings. The overall layout mainly describes the relative position and overall distribution of residential buildings in the settlement, while the arrangement and layout mainly focus on the arrangement and orientation of buildings in the settlement. The above two layout modes can be expressed by the means of characteristics map, as shown in Table 7 and Table 8:

Table 7. Overall layout map of the village buildings.

Type	Spatial Pattern	Typical Village	Distribution	Cause Analysis
Aggregation type	The houses are clustered together and arranged relatively closely, with no particularly obvious grouping features.	Tongban Tun Longmiao Tun	They are generally located in the flat terrain (near the mountains and by the water), on the gentler hillside, or in the hilly land surrounded by mountains.	The dwellings in the settlement are arranged sequentially, relying on favorable terrain and water sources and showing significant aggregation characteristics; the mountains and water bodies did not block or divide the village into blocks.
Partitioned type	The houses in the settlement are grouped together on a smaller scale to form a number of sub-blocks.	Pingmao Tun Guoli Tun	They are generally located on both sides of rivers with more complex directions, or on high mountains with higher terrain.	Due to the obstruction of terrain, road or rivers, the village space is divided into several small blocks, which are separated according to the river terrain. Meanwhile, the existence of families and clans makes villagers live together along the road.

The black boxes represent residential buildings, the green curves represent the village roads, and the red curves are the village boundary lines. The illustrations in Table 8 and Table 9 are the same.

Table 8. The arrangement and layout map of village buildings.

Type	Spatial Pattern	Typical Village	Distribution	Cause Analysis
Radiation type	Buildings spread out from the center of the settlement, mostly found in cluster villages.	Gaoding Village	They are generally located in the lower terrain of the valley, that is, the intersection of two mountains, and the residential houses distribute along the col.	The residential houses in the settlement are arranged in the lower terrain, and the buildings are built between the two mountains. As the mountains continue to extend away, the buildings also expand from the center to the surrounding area, thus forming a typical radial shape.
Skeleton type	There are obvious trunk and branch phenomena of dwellings within the settlement.	Gaoyou Village Pingmao Tun	They are generally found in river valleys with low relief, or on high mountains, or at the intersection of two mountain slopes.	Due to the distribution of terrain and rivers, most of the village buildings are arranged along the hillside or along the rivers, forming the main skeleton of the village spatial arrangement, and the remaining few buildings are distributed on both sides of the main body, thus forming a skeleton-shaped development pattern.
Chaotic type	The distribution of buildings in the settlement is chaotic, with no apparent order or symmetry.	Gandong Tun	It is generally located at the intersection of mountains and rivers, and the buildings constantly meander along the terrain, so the pattern is more chaotic.	The distribution of rivers and terrain is complex, resulting in a haphazard pattern of building development and layout.

The planar morphological characteristics of rural settlements study the geometric features of planar figures formed by settlements and their boundaries, while the spatial layout characteristics of buildings more concentrated on the spatial distribution and interrelation of residential buildings. Although the settlement types can be calculated by quantitative indicators, this section directly gives several basic types and their causes through qualitative analyses, and can roughly summarize the characteristics of residential buildings in typical rural settlements. From the above analyses, it can be seen that the spatial layout of residential buildings is also closely related to their geographic features, and the clan lineage factor also has a great impact on them.

4.2. “Road Structure” Map of Villages

As an important part of rural settlements, roads play an irreplaceable role in the development and progress of villages, and the study on the structural characteristics of roads in rural settlements also has certain reference value for grasping the characteristics and culture of ethnic minorities. According to the study on the planar morphological characteristics of rural settlements [18], the distribution features of buildings and roads only describe the distribution conditions of buildings along the roads, or can express the numerical relationship between the buildings and roads. However, for the general village space, it is more intuitive to study the spatial relationship between roads and buildings, and the structural characteristics of roads also reflect the beliefs and pursuits of ethnic minorities to a certain extent. According to the structural characteristics of the roads in ten typical villages, they are roughly divided into three categories, and their distribution and formation reasons are shown in Table 9:

Table 9. Spatial relationship map of buildings and roads in villages.

Type	Spatial Pattern	Typical Village	Distribution	Cause Analysis
Roads in residential areas	The roads distribute within the building groups and are integrated into the buildings.	Guoli Tun Songmei Tun	They are generally located on the hillside with low slope, or on high mountains with high terrain.	The houses are built on high mountains, and villagers rely on roads to travel, while the roads in the village are in the shape of steps or slopes, and the buildings are connected by a cascade of contour lines.
Roads surrounding the houses	The alignment of the roads revolves around the house layout, that is, the roads are centered on the dwellings.	Longmiao Tun	It is generally found on the banks of low and flat river valleys.	In this case, there will be a river near the village, and the road distribution along the river can not only reduce the construction cost, but also reduce the travelling distance.
Houses surrounding the roads	The houses are arranged sequentially against the road and are regularly located on both sides of the roads.	Gandong Tun Pingmao Tun	They are located in low-lying valleys, the roads are built along the mountains, and the buildings spread out along the roads.	The buildings are spread around the road in sequence. Firstly, due to the topography and landform, the roads are built in the low-lying areas; secondly, the buildings are distributed next to the roads for easy travelling.

As can be seen from Table 9, there are many forms of road structures in typical villages, but we focus on the most typical and key types to extract and illustrate, taking “roads surrounding the houses” and “houses surrounding the roads” as the example, it seems that roads and buildings are interdependent, but the key lies in which side is dominant. Taking Longmiao Tun as an example, the distribution of terrain and river makes the buildings in the village close to the river, and the edges are relatively regular, so building roads outside the village is the most direct and convenient choice, which not only connects the households in the village, but also makes the passage of the main road smoother and safer. In the case of Gandong Tun and Pingmao Tun, the roads are obviously better suited to the terrain and water sources than the buildings, so the buildings are built around the roads.

4.3. “Building-Nature Pattern” Map of Villages

When villagers of ethnic minorities choose the location of village settlements and construct residential buildings, the natural environment is the first factor to be considered. Therefore, studying the interrelationship between natural environment elements and the village architecture is of great significance for understanding the spatial layout and inner characteristics of rural settlements. Based on the literature research, field investigation and GIS calculation results, we can obtain the topographic features of the designated village and the distribution of buildings along the terrain and landform. According to above research results, we classify the “building–nature pattern” type of the village into three categories—“building-mountain and river pattern”, “building–mountain pattern” and “building–terrain pattern”—and each major category is divided into a number of subcategories, as shown below.

4.3.1. “Building–Mountain and River Pattern” Map

The “Building–mountain and river pattern” mainly considers the overall interrelationship between village buildings and the natural environment, focusing on the location of the contour lines and mountains near the settlement, as well as the arrangement rules of residential buildings. In the areas inhabited by ethnic minorities in southern China, the landscape features are the main embodiment and portrayal of the natural environment. We classify the interrelationships and patterns between the residential buildings and landscape into the following categories, as shown in Table 10:

Table 10. “Building–mountain and river pattern” map of the villages.

Village Topography	Schematic Diagram	Representative Villages		Characterization
Mountain intersection type	(The green lines are contour lines, and the black squares are village dwellings)			Most villages of this type are surrounded by mountains, or there is a part of the boundaries of the villages limited by the mountains, and the villages remain in high consistency with the contour lines; in general, the layout of the villages is greatly influenced by the natural environment.
		Gandong Tun	Songmei Tun
		Guoli Tun	Gaoding Village
River valley and flatland type	(The green lines are contour lines, blue lines are rivers, and the black squares are village dwellings)			This type of village is located in a relatively flat river valley; it is arranged along the river and located at the foot of the mountain; the surrounding terrain rises in the distance.
		Longmiao Tun	Xigupo Tun
		Dapao Tun
Mountain and river surrounding type	(The green lines are contour lines, blue lines are rivers, and the black squares are village dwellings)			The village is built on a mountainous terrain or near the river, and the elevation is not decisive at this time.
		Tongban Tun	Pingmao Tun

4.3.2. “Building–Mountain Pattern” Map

Since there are plenty of mountainous areas in southern China inhabited by ethnic minorities, and most of the ethnic minority dwellings are built on the mountains, the relationship between buildings and mountains is extracted and studied separately here, and the distribution characteristics and pattern features of the buildings on hillsides are mainly taken into account. According to the specific values of slope gradient and ground fluctuation in Table 4, Table 5 and Table 6—where the slope gradient describes the steepness of the mountains, and the ground fluctuation reflects the absolute elevation difference, which are both different and related—we combined and analyzed the two sides and classified them according to the standards shown in Table 11:

Table 11. “Building–mountain pattern” map of the villages.

Mountain Features	Schematic Diagram	Representative Villages		Characterization
$\mathrm{High}\mathrm{gradient}\mathrm{and}\mathrm{high}\mathrm{fluctuation}(S_d\ge 22$, $R_{Fi}\ge 50$)				This type of village is located on a mountain with a large slope, the hillside is relatively continuous as a whole, and the height continues to increase.
		Tongban Tun	Songmei Tun
High gradient and low fluctuation ($S_d\ge 22$, $R_{Fi}<50$)				The settlement is on a steep hillside, but the length of the mountain is low, and the height of the mountain does not increase too much.
		Gaoyou Village
Low gradient and high fluctuation ($S_d<22$, $R_{Fi}\ge 50$)				The village is built on a mountain with a gentle slope, but the length of the mountain is large, so the mountain constantly rises.
		Guoli Tun	Gaoding Village
Low gradient and low fluctuation ($S_d<22$, $R_{Fi}<50$)				Villages are usually located in hilly areas with gentle slopes and small scale, and the height fluctuation is low.
		Longmiao Tun	Xigupo Tun

For the first two types in Table 11, although the slopes are both high, the actual ground fluctuation can be quite different due to the inconsistent scale of the mountain, and the situation is similar when the slopes are low. Therefore, the contributions of the two types should be considered comprehensively, and the map of the building–mountain pattern cannot be classified according to one index only.

4.3.3. “Building–Terrain Pattern” Map

The “building–mountain pattern” characterizes the construction and distribution of residential buildings along the mountain, but the indicators inside can only express the characteristics of the mountain at the macro level, but the characteristics and details of the specific distribution of residential buildings cannot be described. Therefore, it is necessary to carry out detailed classification research on the distribution terrain of buildings. The relationship between residential buildings and topography in villages is also an important factor affecting the location and sustainable development of villages, and different ethnic groups prefer different mountain locations. According to the results of field investigation and GIS calculation, the typical building–terrain relationship in Liuzhou is classified into six categories, which are expressed graphically as shown in Table 12:

Table 12. “Building–terrain pattern” map of the villages.

Relationship Between Architecture and Terrain	Schematic Diagram	Representative Villages		Characterization
Valley agglomeration type				The villages are located in valley areas, and the residential buildings are concentrated in the valleys, with less distribution on both sides of the mountain.
		Gandong Tun	Gaoding Village
Mountainside type				The buildings are located on the hillside and in the valleys, and the entire surface of the mountain, except for the top, is covered by dwellings.
		Gaoyou Village
Downhill type				The buildings are arranged along the side of the mountain and are distributed downward.
		Tongban Tun	Xigupo Tun
Mountaintop agglomeration type				The buildings are concentrated at the top of the mountain, and there are no buildings on the hillside or valley floor.
		Guoli Tun	Songmei Tun
Flatland and riverside type				The slopes of the hills where the dwellings are located are relatively low, and they are gathered only on one side of the hill, with water sources distributed at the bottom of the hill.
		Longmiao Tun
Valley and riverside type				The dwellings are located on the slopes on both sides of the valley floor in the middle of the mountains, the slopes are slightly steep, and water sources are distributed at the valley floor.
		Pingmao Tun	Dapao Tun

As shown in Table 12, there are large differences in the terrain distribution characteristics of the ten typical settlements, and when the number of samples increases, it can be expected that the number of basic types will still increase. In addition, the settlements in a certain category basically do not satisfy the characteristics of the same ethnic group or the same region, except Guoli Tun and Songmei Tun. So, it can be concluded that the characteristics of the building–terrain pattern are the most complex, being affected by various factors, and need to be studied further.

4.4. Construction System and Process of the Planar Morphological and Spatial Layout Characteristics Map of Rural Settlements

On the basis of the research content of planar morphology in rural settlements, a relatively complete characteristics map of planar and spatial distribution can be constructed by combining the two-dimensional and three-dimensional studies, and its main categories and expressions are shown in Figure 3. Figure 3 integrates the planar morphology map from Reference [43] with the spatial layout characteristic map developed in this study. The characteristic map construction needs to encompass the main elements within the spatial scope of settlements, such as buildings, roads, mountains, and rivers. Based on the overall layout, settlement buildings, settlement roads, and the building–nature relationship, the spatial characteristic maps are divided into four categories—the first three represent planar characteristics, while the last one represents spatial characteristics. Each type of characteristic map is further classified into three levels, from the meso-, micro-, and specific manifestation perspectives. The outermost ring of Figure 3 employs schematic diagrams to visually represent corresponding spatial characteristics.

Figure 3. Planar and spatial characteristics map system of rural settlements. (In the figure, the black squares represent residential buildings, the blue curves represent the rivers, and the red curves are the village boundary lines. In the road structure map, the green curves represent the village roads; while in the building-nature pattern map, the green curves represent the contour lines.).

According to Figure 3, the map system of ethnic minority rural settlements in southern China was constructed based on planar and spatial layout features of settlements, and this method and system can be applied to typical ethnic minority rural settlements. Therefore, the general method and process of constructing characteristics maps for rural settlements in this paper can be summarized as shown in Figure 4. To construct the spatial characteristic maps, it is necessary to analyze both the natural environment and the layout features of the settlements themselves. From the spatial layout characteristics of rural settlements, we can extract planar shapes, boundaries, and elevation distribution features, while elements such as topography, mountains, and rivers can be derived from the natural environment. The spatial layout characteristics serve as the expressive forms of the maps, while the natural environment acts as an external driving force and influencing factor. By establishing connections between these two aspects, the categories of the maps and their corresponding characteristics can be systematically summarized. The diagram on the right side in Figure 4 provides a refined synthesis of the four categories presented in Figure 3, employing simplified schematic representations for visual expression.

Figure 4. Logic and process of constructing planar and spatial characteristics map for rural settlements.

5. Discussion

Numerous studies have discovered that spatial forms of rural settlements are related to various factors, such as the settlement’s geographical location, social environment, and ethnic culture [44,45,46,47]. In multi-ethnic settlements, the natural environment determines the “regional” aspect of the settlements. However, the ethnic culture is the concentrated expression of the “ethnic character” of the settlements. Hence, ethnic cultural characteristics inherent in ethnic groups should be considered, in addition to the focus on “regional” characteristics, when studying rural settlements of multi-ethnic areas [48]. Therefore, the research on the spatial form of settlements under the influence of different regional and ethnic features is also a very important aspect. The results of the village classification in Table 2 according to region and ethnicity are shown in Table 13:

Table 13. The ethnic and regional distribution of representative villages.

County	Settlement of Han	Settlement of Zhuang	Settlement of Miao	Settlement of Dong
Rong’an County	Tongban Tun	Longmiao Tun, Xigupo Tun	Dapao Tun
Rongshui Miao Autonomous County			Gandong Tun, Guoli Tun, Songmei Tun	Pingmao Tun
Sanjiang Dong Autonomous County				Gaoding Village, Gaoyou Village

According to Table 4 and Table 10 in the paper, the spatial layout characteristics of settlements in Rong’an County exhibit similarities. Especially for the three settlements of Longmiao Tun, Xigupo Tun, and Dapao Tun, they show a high degree of resemblance in terms of elevation, slope gradient, ground fluctuation, and ground roughness. We take the Miao settlements of Gandong Tun, Songmei Tun, and Dapao Tun as examples. Dapao Tun is a Miao settlement in a county dominated by Han people. Compared with the Miao settlements in Rongshui Miao Autonomous County, the elevation and ground undulations of Dapao Tun have decreased significantly.

These findings demonstrate that spatial layout characteristics exhibit certain similarities among settlements of different ethnic groups within the same geographic region. On the other hand, the spatial layout characteristics show distinct variations among settlements of the same ethnic group across different regions. This suggests that within a shared geographical context, different ethnic groups gradually develop converging settlement location preferences through long-term integration. These findings provide clear evidence of the significant influence of ethnic factors on the spatial layout of rural settlements, establishing a foundation for future expanded and extended research based on the current study.

In multicultural convergence zones, the ethnic and regional characteristics of ethnic minority rural settlements are particularly pronounced. Future research could examine their influences from diverse analytical perspectives. Given that regional and ethnic factors often interact synergistically, initial studies should employ a single-variable control approach to isolate the effects of ethnicity. This method would enable systematic analysis of how ethnic factors independently affect settlement spatial patterns. Subsequent research could then investigate the combined effects of both factors, examining their interaction and synergistic influences on settlement patterns. Furthermore, genetic map approaches could be employed to analyze these relationships, offering the unique advantage of probing beyond superficial spatial characteristics to uncover intrinsic genetic determinants. This would help us explore the operative mechanisms and mutual influence between regional and ethnic factors.

The southern region of China represents a significant zone of multicultural convergence, where pronounced ethnic integration has occurred through both environmental adaptation and interethnic exchange. Based on the research in this paper, conducting research on the influence mechanism of ethnic characteristics on the spatial layout characteristics for ethnic minority rural settlements can provide a theoretical basis for the planning and construction of rural settlements. Furthermore, this can also offer practical references for the coordinated development among multiple ethnic groups, promoting complementary advantages and common progress among multi-ethnic settlements.

6. Conclusions

This paper takes the ethnic minority rural settlements in southern China as the research object and the traditional ethnic minority villages in Liuzhou, Guangxi, as specific cases. At the spatial scale level of the settlements, GIS analysis method is applied to calculate geographic information elements and classify and summarize the spatial features. On this basis, the map system of the planar morphology and spatial layout characteristics has been systematically constructed for ethnic minority rural settlements in southern China. The main research results are concluded as follows:

(1)

ArcGIS software is applied to calculate geographic indicators (slope gradient, slope direction, ground fluctuation, and ground roughness) that can express the topographic and geomorphological features of the settlement. On one hand, these geographic indicators can explain the cause of spatial layout characteristics of the settlement; on the other hand, they extract the factors that can reflect the spatial layout features of rural settlements. Subsequently, the spatial layout characteristics map of the settlement can be constructed according to the manifestation of the factors.

(2)

The research shows that ethnic minority rural settlements in southern China generally follow contour lines in their distribution, and they give priority to the gently sloping terrain regardless of the surrounding topography. The slope direction of the settlement site is not limited to the south, and all directions are available, which shows that the site selection of rural settlements does not only consider the sunshine factor, but also takes into account the factors of sunshine, traffic, and water source comprehensively.

(3)

This study adopts a single-settlement perspective, focusing on the spatial relationships between residential buildings and topographic features such as landforms, mountains, and rivers. The characteristic map types are classified based on the composition of various elements within the settlement space, while the spatial layout characteristics are quantified and expressed through calculated results of specific indicators. The proposed methodology provides a theoretical foundation for optimizing the utilization of spatial resources in settlements and guiding the planning and development of rural settlements. The method proposed in this paper is general and can be extended to the general study of rural settlements.