Quantitative Research of Traditional Village Morphology Based on Spatial Genes: A Case Study of Shaanxi Province, China

Abstract

As urbanization accelerates, many traditional villages face the threat of destruction or disappearance. To better protect and utilize the cultural heritage of traditional villages, it is essential to deeply analyze the inherent patterns of their spatial morphology. This paper selects Nihegou Village in Yulin City, Shaanxi Province, China, as a case study. Utilizing the theory of spatial genes, a quantitative inheritance model was developed, integrating natural, physical, and intangible spatial factors. Through the collection of multidimensional spatial data, such as village topography, slope, and aspect, combined with GIS spatial analysis and the AHP-Fuzzy Comprehensive Evaluation method, the spatial morphological characteristics and genetic inheritance of Nihegou Village were identified, decoded, and quantitatively assessed. Based on the assessment results, corresponding conservation and development strategies were formulated. The findings show that the formation and development of Nihegou Village’s spatial pattern are closely related to factors like the natural environment, social policies, and economic technologies. The terrain and the process of urban modernization have impacted the inheritance and development of Nihegou Village’s intangible spatial genes. The application of spatial quantitative analysis methods to formulate strategies for the preservation and inheritance of traditional village spatial characteristics not only provides theoretical guidance for village planning and conservation rooted in cultural heritage, but also effectively safeguards and revitalizes the spatial gene inheritance of Nihegou Village, contributing to the village’s sustainable development.

1. Introduction

Traditional villages represent living embodiments and serve as important carriers of agricultural culture, developed through prolonged interactions between humans and their natural environment [1]. These villages also represent cultural heritage in both tangible and intangible forms, possessing irreplaceable historical, cultural, scientific, artistic, and research value [2]. The village landscape represents a sustainable cultural landscape [3]. The diversity of cultures forms a vibrant and colorful world, serving as one of the foundations of global development and a significant force driving sustainable growth. However, with the deepening of globalization, developing countries such as China are becoming more and more urbanized, and numerous substantial transformations have occurred in rural regions, affecting both agricultural production and lifestyles. During urbanization and modernization, traditional village and rural cultures are either vanishing or being integrated [4]. Traditional villages are facing many problems such as constructive destruction, ecological pollution, aging of traditional buildings, and functional degradation [5,6]. At present, China has carried out a great deal of work in the protection of traditional villages. Since 2012, the Ministry of Housing and Urban-Rural Development (MOHURD), the former Ministry of Culture (now the Ministry of Culture and Tourism, MOCT), and the Ministry of Finance (MOF) of the People’s Republic of China have jointly announced, in six batches, the selection of 8155 traditional Chinese villages for rescue and preservation efforts [7]. In 2017, to enhance the protection and development of traditional villages, China launched the “rural revitalization strategy” [8].

Traditional villages are also an important carrier of the vernacular memory and history and culture of Chinese civilization [1]. They are also a concentrated manifestation of rural inheritance. Scholars from disciplines such as geography, architecture, urban planning, tourism, and design have been actively seeking targeted strategies for the preservation and development of traditional villages [9,10]. Recently, the “landscape gene” theory has seen growing application in research focused on conserving traditional villages, thus promoting the study of their spatial structures [11]. The application of landscape gene theory has offered new insights for recognizing traditional settlement landscapes. In the last ten years, substantial progress have been made in studying the spatial genes of traditional villages [12]. However, challenges remain, including the incomplete development of settlement gene theory, a lack of systematic and practical research.

Therefore, we explore the following aspects of traditional villages: (i) the spatial characteristics of traditional villages, (ii) the construction of a recognition system based on spatial genes, (iii) the pathways for the protection and inheritance of traditional villages guided by spatial genes. We identify the value connotations of traditional village heritage through spatial gene analysis, beginning with the material and intangible spatial genes, and create a model for quantifying spatial gene inheritance. Finally, using Nihegou Village in Yulin City, Shaanxi Province, China, as a case study, we deconstruct and quantify traditional villages, exploring new approaches for revisiting spatial research in traditional villages, refining spatial gene theory, and providing useful references for the inheritance and preservation of traditional villages.

2. Literature Review

The concept of spatial genes originated from urban morphology theory [13], referring to detectable spatial markers, configurations, and relational indices that shape the form and structure of human habitats. The term “gene” (originally “Gen”) was proposed by Johannsen in his 1909 work, “Elemente”, as an abbreviation for “pangene” [14]. In 1976, Richard Dawkins introduced the term “meme” in his book “The Selfish Gene”, identifying cultural genes as the fundamental units of cultural transmission [15]. Susan Blackmore later drew parallels between biological gene and “meme”, suggesting that while biological gene govern evolution, “meme” dictate cultural transmission [16]. Spatial gene technology aims to decode the “DNA” or the latent “condensed social facts” that generate observable traditional village forms [11].

The study of spatial genes originated from the Morphogenesis Theory proposed by Conzen in 1988. This theory explains how the architectural environment evolves into a unique spatial logic under the influences of geographical, socio-cultural, and historical forces [17]. The concept of spatial genes is deeply rooted in urban morphology and cultural landscape gene theory (CLGTS), serving as a key framework for understanding how traditional villages adapt and evolve in response to socio-economic and environmental changes. Spatial genes are an extension of the concept of cultural genes. This approach not only studies the physical forms of space but also interprets these forms as expressions of underlying social structures and relationships, reflecting the convergence of geographical, cultural, and historical forces [18]. In 2003, PL Liu first proposed the concept of Traditional Settlement Cultural Landscape Genes (CLCTS), identifying and categorizing the spatial structures of traditional villages [19]. Zui Hu and colleagues applied semiotics to visualize CLCTS and create a database, greatly advancing research in this field [20]. Xiang et al. [21] selected six traditional Dong villages within Pingtan River Basin as case studies to quantify the spatial gene diversity. By using the spatial gene diversity index, they assessed the present condition of the villages’ conservation and growth. This approach enables a deeper understanding of how these villages serve as repositories for cultural continuity and heritage. These studies demonstrate how traditional villages can be decoded like DNA, revealing the “cultural DNA” or “condensed social facts” that shape the observable forms of traditional villages.

Academic studies on rural settlements began in the 19th century [22]. Analyzing the spatial forms and architectural structures of traditional settlements helps deepen our understanding of the human adaptation process to the environment, community social structures, and the crystallization intangible heritage values within material culture. Foundational descriptive works, such as Jean Brunhes’s “Principles of Human Geography” and Carl Sauer’s “The Morphology of Landscape” [23]. These works laid the foundation for more quantitative studies in the 1960s, though research initially focused on descriptive analysis rather than generative process. Recently, these methods have advanced through the use of quantitative spatial analysis techniques and Geographic Information Systems (GIS) by Deniz Kılıc et al., who applied these techniques in selecting rural settlement locations and designing eco-villages in Erzincan, Turkey [24]. Moving beyond the descriptive cataloging of spatial forms, PL Liu presented the concept of “cultural landscape genes” related to traditional villages [25]. The early stages of landscape gene theory focused on “landscape imagery”, while later stages examined the mechanisms of identifying and expressing landscape genes in traditional settlements across different regions. Based on the concept of landscape genes, Hao Wu et al. explored the spatial characteristics of traditional villages in Huizhou and their inheritance and protection mechanisms, including the cultural value of the landscape of ancient Huizhou villages and the process of its formation [26]. Zhang et al., using Qianxiewan Village in Pingdingshan City as a case study, applied the landscape gene theory to analyze various aspects of the village, including its environmental setting, spatial layout, main buildings, and cultural background. They established a landscape gene identification system for Qianxiewan Village [27]. However, critics argue that inductive methods relying on subjective interpretation overlook the need for hypothesis testing for the quantifiable generative mechanisms behind the observed settlement forms.

To seek more rigorous analytical methods, studies on village morphology have utilized measurable indicators of layout, shape, land use, and architecture in spatial science. Dawid Soszyński et al. employed cartographic spatial analysis and conducted semi-structured interviews with local residents to examine the spatial features of rural tourism sites in 17 tourist villages located in the Łęczna-Włodawa Lake District, Eastern Poland [28]. While these analyses ensure consistency, they remain confined to specific variables that are not integrated. Recent village studies have also incorporated concepts from urban morphology, integrating spatial genes with quantitative techniques such as space syntax, geographic information systems, and statistical analysis. Researchers like Liu [29], Duan [30], and Wu [31] have employed methods including space syntax, statistical analysis, and GIS technology to conduct quantitative studies and contemporary mapping of the spatial morphology of traditional villages in areas such as the Guanzhong region of Shaanxi Province, the Fuzhou area of Jiangxi Province, and Guizhou Province, offering innovative ideas for rural spatial planning through more scientific approaches [32]. These techniques aim to decode the generative principles that produces observable residential forms. However, expanding the application of these methods across different villages remains necessary. Techniques from space syntax and geographic information systems offer greater rigor than earlier descriptive studies.

With the influence of urbanization, traditional village landscapes have suffered various degrees of damage, accelerating their disappearance. During the early 1980s, Yisan Ruan conducted research on the ancient town of Zhouzhuang in Jiangnan and formulated a conservation plan [33]. He proposed a sixteen-character principle: “preserve the ancient town, develop new areas, boost the economy, and promote tourism”, which established a solid foundation for the preservation and study of traditional village. In 2006, Jicai Feng and Yisan Ruan published the “Xitang Declaration”, the first declaration in China’s cultural heritage conservation history advocating for the protection of ancient villages with support from society and international academia. Subsequent studies on traditional village conservation and development adopted diverse perspectives and methodologies, integrating multidisciplinary approaches. For example, Wang Ping et al. emphasized the significant cultural value of traditional villages. From an archival science perspective, they assessed the advantages and limitations of the intangible cultural heritage protection model, the traditional village directory protection model, and the ecological museum protection model, further exploring the feasibility and rationale of archival protection strategies for traditional ethnic minority villages in Southwest China. [34]. Kanhua Yu analyzed the current state and challenges of traditional village development from an urban and rural planning perspective. Using Lianhu Village as a case study, they proposed conservation and revitalization strategies for the village, examining these from the perspective of changes in village life, industrial structure, and multiple dimensions of villagers’ livelihoods [35].

Simultaneously, the United Nations Educational, Scientific and Cultural Organization (UNESCO) protects traditional villages by implementing regulations and promoting the sustainable use of these cultural and natural heritage sites [36]. From a broader perspective, Amy Strecker in “The Oxford Handbook of International Cultural Heritage Law” discusses how legal frameworks support the protection of cultural landscapes across jurisdictions, underscoring the crucial role of international law in shielding these sites from environmental and human threats [37].

Consequently, facing the pressures of urbanization and modernization, traditional villages, as spatial carriers of cultural heritage, urgently require a quantitative analysis of their spatial genes. This analysis is essential to reveal the generative logic of traditional village spatial genes, thereby establishing a sustainable assessment framework and formulating a balanced strategy that simultaneously ensures the protection and development.

3. Quantitative Inheritance System Modeling of Spatial Genes of Nihegou Village

Based on comprehensive analysis of current research and relevant literature, a novel integrative framework has been developed for the quantitative examination of spatial genetic inheritance in traditional settlement patterns (Figure 1). The spatial genes of traditional villages are categorized into three primary groups: natural environment genes (e.g., altitude, slope, hydrophilicity), physical space genes (e.g., buildings, streets, village boundaries), and intangible spatial genes (e.g., local customs, folk beliefs). The spatial genes of traditional villages are deeply embedded hereditary characteristics of the village’s culture and spatial form, reflecting the interactions between the village and its natural, social, and cultural environments across different historical periods. Among these, intangible culture is a crucial component of spatial genes. It is manifests not only in the village’s folk activities and lifestyle but also in the overall spatial layout and morphological features. For instance, the traditional sacrificial rituals and daily practices of Nihegou Village’s residents have significantly influenced the spatial organization of the village, becoming integral to its spatial genes and ultimately shaping its unique spatial form. Each of these spatial genes exhibits stable patterns that have persisted to the present day. For example, the natural environment genes of Nihegou Village, such as its distinct terrain and hydrophilic characteristics, have shaped the village’s spatial layout and remained stable over time. Similarly, the traditional loess cave dwellings, representing physical space genes, embody architectural styles that have been preserved across generations.

The first step involves the precise identification and deconstruction of these spatial genome elements. For instance, the natural environment genome can be broken down into fundamental components such as altitude, slope, aspect, and hydrophilicity. Similarly, the physical space genome is decomposed into elements that include buildings, streets, and village boundaries. Subsequently, these genomic components are decoded and quantified. Customized metrics are developed to enable precise measurement and coding of the characteristics of each gene. Using this approach, each gene in a traditional settlement is precisely quantified, providing a robust foundation for further analysis.

In conclusion, through processes of replication and variation, these meticulously encoded spatial characteristics manifest in the distinct forms of traditional villages. This model not only unravels the logic underpinning village morphogenesis but also provides a quantifiable, scientific approach to preserving and perpetuating the essence of traditional villages.

4. Materials and Methods

4.1. Study Area

Nihegou Village is located in Yulin City, Shaanxi Province, China. It is bordered by the Yellow River to the east and surrounded by mountains on the south, west, and north. The village is situated at an elevation of approximately 800 m on the Loess Plateau, and experiences a typical temperate continental semi-arid monsoon climate (Figure 2). Nihegou Village consists of 213 households, divided into six groups, with a total population of 806 individuals. However, the current permanent population stands at approximately 170 people, merely one-fifth of the registered population. Nihegou Village was listed as one of China’s third batch of designated traditional villages in 2014. Its unique geographical location has protected it from wartime devastation, allowing for the preservation of ancient historical relics and a long-standing folk culture. Additionally, its proximity to the Yellow River facilitated the transportation of goods by water, establishing it as an important ancient ferry crossing and contributing to a relatively prosperous economy. Today, Nihegou Village retains numerous century-old residential cave dwellings and public historical buildings such as ancient opera stages, with architectural decorations and materials that have been well preserved through generations. Furthermore, Nihegou has a strong regional cultural character of northern Shaanxi, with abundant local folk cultural resources, numerous surrounding cultural relics, and natural landscapes. It is home to Shaanxi’s largest group of cliff carvings, historical landmarks, grottoes, and revolutionary sites. Notably, the village preserves intangible cultural heritage of northern Shaanxi, including yangko dance and paper-cutting [38]. During the “Dajiao” sacrificial ceremonies, old artists from the surrounding villages are invited to perform with the suona horn and trumpet. The specific names of the intangible cultural heritage and their inheritors are listed in

Table 1. Statistics on the main intangible cultural heritage inherited in Nihegou Village.

Intangible Cultural Heritage	Main Features	Main Inheritors
North Shaanxi folk song	Rough, high-pitched, spontaneous, extremely sing-song	Xiangrong Wang
yangko	Grandiose, fast-paced, enthusiastic, and varied formations	Junyi He, Zengheng Li, Jianming Wei
Xintianyou	The language is natural, simple, vivid and graphic	Gui Liu
storytelling	Bold, rough, simple language, but delicate feelings	Jungong Zhang
paper-cut	Simplicity and skillfulness with a focus on living customs	Fengying Li, Hongxia Cao
suona horn	Bright tone, good imitation of the human voice, and animal calls	Shifa Wang, Qishan Li

.

4.2. Data Sources

The research data include village administrative boundaries, rivers, roads, DEM data, satellite imagery, traditional village point data, photos from field surveys, manually supplemented building and compound outlines derived from satellite imagery. All these datasets are vector data. The research data were primarily gathered via field surveys, onsite inspections, questionnaires, and literature reviews. In September 2023, the research team carried out an extensive field survey, including on-site interviews and questionnaires, spanning more than 20 days. Data related to intangible spatial genes were collected from various sources, combining literature reviews, on-site interviews, and questionnaires. Information on the historical development, cultural heritage, and social dynamics of Nihegou Village was gathered using literature and questionnaire methods. This information was used to identify the key factors influencing the intangible spatial genes of traditional villages. Additional sources of information consist of the Digital Museum of Chinese Traditional Villages (http://www.dmctv.cn) and the Shaanxi Province Intangible Cultural Heritage Data (https://www.sxlib.org.cn/dfzy/feiwuzhi/sjyp/ (accessed on 6 September 2023)). Topographic data were sourced from geospatial data clouds (https://www.gscloud.cn/ (accessed 6 September 2023)). The digital elevation model data were acquired through the National Geographic Information Resources Catalogue Service System (https://www.webmap.cn/). Satellite imagery was acquired from Google Earth with a precision of 18 m, allowing for the subsequent addition of vector data like building and compound outlines in the study area. Furthermore, all vector data were meticulously corrected in Arc GIS 10.8 to maintain data consistency and validity.

4.3. Methods

Based on the spatial gene quantification model proposed in this study, we analyze the morphology of traditional villages and explore the underlying principles that shaping their abstract forms. In considering the methodology, we considered alternative approaches including spatial autocorrelation analysis and multivariate statistical analysis. Although these methods offer different perspectives, they have inherent limitations in capturing the multidimensional nature of spatial genes. The system model incorporates urban geography, landscape ecology, fractal geometry, spatial syntax, computer programming, statistics, and other interdisciplinary methods, enabling a more comprehensive and accurate quantification of spatial genes in traditional villages. This approach encompasses all stages from morphology mapping to quantitative analysis. All data calculations and analyses were conducted using Arc GIS, DethmapX-0.7.0 and Rhino 7. Figure 3 presents the methodological chart.

4.3.1. DEM Data

The DEM (digital elevation model) is a three-dimensional digital model describing the terrain elevation information [39]. The DEM expresses the undulation of the terrain, which mainly includes the following two forms: (1) regular grid DEM data: the terrain surface is divided into regular grids, and each grid contains the elevation information of the corresponding points, which expresses the terrain information through the grid point elevation values; (2) irregular triangular mesh DEM data: the irregular triangular mesh is used to express the terrain information, which is the most common form of DEM data at present. It generates a triangular irregular network TIN through the interpolation method, and each triangle contains the elevation values of three fixed points, so as to establish the digital expression of the terrain.

4.3.2. The Shape Index

This paper is based on Prof. Pu Xincheng’s grounded theory research [40]. The shape index is a mathematical metric in landscape ecology that assesses the complexity of a patch’s shape by determining its deviation from a circle or square with the same area. The shape index value increases with the complexity and irregularity of the patch shape. For example, referencing a circle of the same area, the ratio of the shape’s perimeter to that of the circle is calculated. This ratio, derived from the outline’s perimeter, determines roundness. Roundness indicates how much a shape deviates from an equivalent-area circle, also referred to as “shape deviation” [41]. To scientifically deconstruct the boundary shape of traditional villages, this paper study uses ellipses of equivalent area and aspect ratio as references, creating virtual boundaries at macro, meso, and micro scales (100 m; 30 m; 12 m). And then calculate the shape index of these three boundaries. The calculation formula is as follows:

$$\begin{gathered} \lambda ={\displaystyle \frac{a}{b}} \\ S={\displaystyle \frac{P}{(1.5\lambda -\sqrt{\lambda }+1.5)}}\sqrt{{\displaystyle \frac{\lambda }{\mathsf{A}\pi }}} \end{gathered}$$

(1)

In which, $a$ and $b$ represent the length (m) and width (m) of the smallest enclosing rectangle of the traditional village boundary (m); P stands for the perimeter of the traditional village boundary (m); A denotes the area within the traditional village boundary (${\mathrm{m}}^2$); and λ signifies the width-to-height ratio of the traditional village boundary.

4.3.3. Distance Analysis

Distance analysis is a fundamental technique within the domain of spatial science, widely employed across geography, ecology, urban planning, and notably within geographic information systems (GIS) [42]. Using ArcGIS, distances between a series of geographic features or points depicted on a map are calculated and analyzed, enabling the interpretation and understanding of complex spatial relationship networks and the patterns that emerge from them. Distance analysis, as a crucial tool in the quantitative study of traditional village spatial genetics, facilitates the examination spatial continuity. The significance of distance analysis is anchored in its proficiency to convert complex spatial information into measurable matrices [43].

Thus, distance analysis transcends mere spatial measurement; it serves as a quantitative framework that associates physical distances with the qualitative facets of traditional village existence. To scientifically assess the hydrophilicity of traditional villages, this study uses the average minimum distance from the center points of village structures to the riverbank boundary as an indicator of the hydrophilicity. A shorter distance indicates higher hydrophilicity. Distance analysis not only provides quantifiable data on the physical distances between settlement structures and water sources, but it also reveals how natural and anthropogenic factors shape the spatial layout of settlements.

4.3.4. AHP-FUZZY Method

The AHP-Fuzzy Comprehensive Evaluation (FAHP) method combines the Analytic Hierarchy Process (AHP) and the Fuzzy Comprehensive Evaluation (FCE), both valued for their unique strengths in multifactorial analysis. This hybrid method employs hierarchical analysis to systematically decompose elements related to the overarching objectives into a cascading, multilevel structural model, establishing explicit relationships and weightings at each stratum [44].

With this approach, decision making moves beyond traditional binary limitations and embracing the subtleties of fuzziness that more closely mimic the complexities of real-world scenarios. AHP brings to the table its robustness in structuring problems hierarchically and in assigning logical quantitative values to subjective judgments, while FCE contributes its capability to handle imprecision and ambiguity inherent in human reasoning [45].

While determining the relative weights of the indicators, the standards’ relative importance was assigned based on the AHP scale. This scale helps decision-makers create pairwise comparison matrices (PCMs). The PCMs indicate whether each element is equally strong, moderately stronger, significantly stronger, much stronger, or extremely stronger than other elements. These relative strengths are subsequently converted into numerical values, as demonstrated in

Table 2. Intensity of importance definition table.

Intensity of Importance	Definition
1	Equal importance
3	Moderate importance
5	Strong importance
7	Very strong importance
9	Absolute importance
2, 4, 6, 8	Intermediate values

.

The following steps are used to determine the relative weights of the indicators through the AHP process:

(1)

Constructing the judgement matrix

The judgment matrix is an important basis for weight calculation, layer by layer, the evaluation criteria layers B₁, B₂…B₈ and its subordinate evaluation indicators C₁, C₂…C₂₄ are compared two by two and assigned values of importance. The judgment matrix C_ij (i, j = 1, 2, …, n) is constructed, indicating the relative importance of C_i to C_j for the affiliated guideline layer; Here, n denotes the number of indicators. The judgment matrix is derived, and the calculation formula is given as follows:

$$C=C_{ij}\left[\begin{array}{ccc}{C}_{11}& \cdots & C_{1n}\\ ⋮& \ddots & ⋮\\ C_{1n}& \cdots & C_{nn}\end{array}\right]$$

(2)

(2)

Detecting consistency in judgement matrices

This research uses the product approach to perform a consistency verification on the judgment matrix, ensuring the rationality of the evaluation data. The calculation is as follows. Normalize each column of the matrix, where i, j = 1, 2, …, n:

$${\overline{C}}_{ij}={\displaystyle \frac{C_{ij}}{{\sum }_{i=1}^n{C}_{ij}}}$$

(3)

Perform summation:

$$W_i=\sum _{j=1}^n{\overline{C}}_{ij}$$

(4)

Normalize the vector:

$$W_i={\displaystyle \frac{{\overline{W}}_i}{{\sum }_{j=i}^n{\overline{W}}_j}}$$

(5)

Calculate the Consistency Ratio (CR) using Formula (2). This checks if the constructed PCM is consistent. If the CR < 0.1, then it is considered consistent.

$$CR={\displaystyle \frac{CI}{RI}}$$

(6)

The Random Index (RI) and the Consistency Index (CI) are applied in the calculation by using Formula (7).

$$CI={\displaystyle \frac{\left({\lambda }_{max}-n\right)}{\left(n-1\right)}}$$

(7)

Here, ${\lambda }_{max}$ represents the maximum eigenvalue of the PCM.

(3)

Detecting consistency in judgement matrices

Several techniques can be used to derive FAHP weights from a pairwise comparison matrix. The result is either a set of fuzzy weights or crisp weights. Establish the fuzzy evaluation matrix R for each indicator, and perform fuzzy operations between the weight vector W and matrix $R$ to derive the comprehensive evaluation vector $V$. Label the comprehensive evaluation vector for each indicator at the sub-criterion layer as $V_{C1}$, $V_{C2}$, $V_{C3}$, …, $V_{Cn}$, where n represents the total number of evaluation indicators. The formula for calculating fuzzy weights is:

$$V=W°R=(V_{C1}, V_{C2}, V_{C3}\dots \dots V_{Cn})$$

(8)

5. Results

5.1. Natural Environmental Genomes

This section presents the calculated results of elevation, slope, slope direction, and hydrophilic intensity of Nihegou Village, Yulin City, Shaanxi Province, China. The natural environmental elements of Nihegou Village have remained relatively stable over time. The elevation and slope features of the village have remained consistent, primarily due to the natural terrain of the Loess Plateau.

5.1.1. Altitude Gene

Based on DEM analysis, the study area’s minimum elevation is 695 m, while the maximum elevation reaches 984 m. The study area is subdivided into 15 intervals based on topographic features using the Jenks natural breaks method in ArcGIS. The spatial distributions of residential houses at various elevations are then derived by overlaying them with residential house data, reflecting the elevation-related distribution characteristics in the study area (Figure 4).

As shown in Figure 4, the settlements of Nihegou Village are concentrated between 720 and 840 m above sea level, with the lowest dwellings located in the foothills at 720 m and the highest in the Shiwa flatlands at 840 m. Based on the elevation data of the study area, the dwellings are spread across the central and lower elevation zones.

5.1.2. Slope Gene

According to the slope classification by the International Geographical Union Commission on Detailed Topographic Mapping for Geomorphological Surveys and Geomorphological Survey Mapping Applications (CDPM) [46], slopes are categorized into five intervals: $\le 2°$, $2°~6°$, $6°~15°$, $15°~25°$ and $>25°$. Slopes of $\le 2°$ are flat, 2°~6° are gentle slopes, 6°~15° are slopes, 15°~25° are moderately steep slopes and >25° are steep slopes [47]. The spatial distribution of residential buildings across different slopes can be determined after superimposed analysis (Figure 5).

It is observed that 57% of Nihegou Village residents live on slopes ranging from 6°~15°, even though the village of Nihegou has slopes of more than 25°, and the degree of surface runoff and erosion is relatively small.

5.1.3. Slope Orientation Gene

Based on the slope orientation as the defining criterion (

Table 3. Slope orientation definition criteria.

Slope	Direction	Azimuth Angle (°)
Sunny Slope	South	157.5–202.5
	Southeast	112.5–157.5
	Southwest	202.5–247.5
	West	247.5–292.5
Shady Slopes	North	337.5–22.5
	Northwest	292.5–337.5
	Northeast	22.5–67.5
	East	67.5–112.5

), the slope orientation is categorized into shady slopes and sunny slopes. The results are illustrated in Figure 6. Furthermore, disregarding sunshine duration, the ratio of buildings situated on sunny slopes was calculated using the sunny slope ratio. For the buildings situated on partially shaded and partially sunny slopes, we take half of their count and add it to the number of buildings on sunny slopes to determine the sunny slope rate. Following this calculation, it was determined that the insolation slope ratio in Nihegou Village is 0.63.

5.1.4. Hydrophilic Gene

This study employed distance analysis to determine the minimum distance from the center point of the structure to the river’s edge [48]. The hydrophilicity index is was calculated based on the shortest distance from the center of a building to the river boundary. The shorter the distance, the greater the hydrophilicity. For each campsite, this study calculated the average hydrophilicity to represent the hydrophilicity of the entire village. Following the analysis, the results are displayed in Figure 7. The average value of the shortest distance of the buildings from the river in Nihegou Village is 96.98 m, indicating a relatively high degree of hydrophilicity.

5.2. Physical Space Genome

The physical space genome, including building styles, village boundaries, and street networks, has evolved throughout different historical periods. For example, the traditional loess kilns in Nihegou Village reflect architectural forms from the Ming and Qing Dynasties, illustrating continuity in building styles over time. However, newer structures have adopted more modern architectural styles while maintaining traditional design elements. The village boundary has also adapted to socio-economic changes, expanding or contracting in response to population dynamics. This indicates a dynamic yet continuous evolution of the physical space genome.

5.2.1. Building Gene

Nihegou Village households are in residential compounds due to the shape of the situation, facing different, staggered heights, and their distribution is relatively scattered, with more than 60 percent of the residential buildings using kiln buildings, in the formation of the ancient kiln cave community. There are 228 courtyards, 61 built during the Qing Dynasty, 40 built during the Ming Dynasty, and 13 immovable cultural relics exist in Nihegou Village.

5.2.2. Village Bounder Gene

This section presents the results of shape index calculations. The delineation of Nihegou Village’s large, medium and small boundaries is illustrated in Figure 8. By employing the shape index calculation method detailed in this paper [49], the boundary’s morphological characteristics and related indicators of Nihegou Village are computed mathematically. In addition, the three shape indices were weighted in order to derive a composite index. The outcomes of the calculations are displayed in

Table 4. Morphological indexes of a border.

	$\mathit{\lambda }$	S1	S2	S3	S
Nihegou Village	1.70	5.98	3.25	1.40	1.74

$\lambda$: aspect ratio, S₁: shape index for small borders, S₂: shape index for middle borders, S₃: shape index for big borders, and S: weighted shape index.

.

5.2.3. Street Gene

By using the spatial texture map and field survey data from Nihegou Village, we employed axes to illustrate the network structure of the village’s streets and lanes, thus creating its spatial axis map. This map was subsequently imported into DepthmapX-0.7.0 software to calculate integration and comprehensibility, leading to the production of an axial map displaying connection values, a global integration map, and a regression analysis for comprehensibility (Figure 9). Furthermore, using the photographs from the field survey, a typical street profile of Nihegou Village was delineated (refer to Figure 10).

After the calculation, the street gene indicators in Nihegou Village are shown in Figure 9. The higher the integration degree, the greater the spatial accessibility and comprehensibility [50], indicating that the local spatial structure supports the establishment of overall space perception, and when the correlation coefficient is greater than 0.45 (the formation of a 45° straight line by scattering points is considered to be the most desirable state), the comprehensibility of the whole street system is higher [51]. Based on the calculation results, Nihegou Village’s street system accessibility is high, and its spatial structure is also more complete. The street system in Nihegou Village is clear and unambiguous, either due to the topography of the land or in situ, and most streets are between 1.5 and 3.5 m. The street system in Nihegou Village has a high degree of comprehensibility.

5.3. Intangible Spatial Genome

This section will show the evaluation results of intangible spatial genes in Nihegou Village, Yulin City, Shaanxi Province, China. The AHP method constructs the evaluation system for intangible spatial genes, calculates the weights and relative weights of each layer’s indicators, and uses Fuzzy Comprehensive Analysis to assess the intangible spatial genome of Nihegou Village.

5.3.1. Establishment of the Evaluation System

The evaluation system is a relatively complex system with many influencing factors. To establish a comprehensive, scientific, objective, and systematic evaluation system for the intangible spatial genetic value of Nihegou Village, in-depth research on the current situation and the cultural environment of the village was conducted. A significant amount of information and data were obtained through field research. During these investigations, we conducted in-depth interviews and discussions with local villagers, cultural heritage inheritors, and members of the village committee, collecting extensive firsthand information on Nihegou Village’s intangible cultural heritage, spatial layout, folk activities, and historical development. Additionally, we carried out detailed field surveys and documentation of the village’s architectural styles, road networks, and natural environment. These research efforts provided us with a substantial amount of valuable data, providing a solid foundation for the construction of the evaluation system. Following thorough research and referring to the “Indicator System for Evaluation and Recognition of Traditional Villages (Trial)”, “Typological Characteristics and Evaluation Criteria for Cultural Landscapes”, “Classification, Investigation and Evaluation of Tourism Resources”, “Operational Guidelines for the Implementation of the Convention for the Protection of the World Cultural and Natural Heritage” [52], and other standards related to evaluation of traditional villages, and combining with the actual situation of Nihegou Village, this paper follow the four standards of wholeness, practicability, hierarchical, and objectivity to construct a system that includes folk arts, folk stories, and folk culture. An evaluation system of indicators for evaluating the genetic status of intangible spatial genes in the village was constructed, including 8 guideline layers and 24 evaluation factors, such as folk art, folk stories and local dialects, and the questionnaire was designed according to the factors included, and the evaluation indicators were selected to carry out the evaluation (

Table 5. Index system of immaterial spatial gene evaluation of Nihegou Village.

Target Layer	Criterion Layer	Evaluation Indicator Layer
A Evaluation of Intangible Spatial Genetics in Nihegou Village	B1 Folk Art	C1 Historical Continuity
		C2 Artistic Creativity
		C3 Public Participation
	B2 Folktale	C4 Originality of Stories
		C5 Effectiveness of Oral Communication
		C6 Cultural and Educational Value
	B3 Local Dialect	C7 Frequency of Use
		C8 Status of Dialect Preservation
		C9 Mechanism of Language Inheritance
	B4 Dietary Features	C10 Diversity of Diet
		C11 Culinary Skills
		C12 Social and Cultural Influence
	B5 Production Techniques	C13 Degree of Skill Preservation
		C14 Ability for Skill Innovation
		C15 Economic and Practical Value
	B6 Local Custom	C16 Degree of Custom Inheritance
		C17 Social Cohesion
		C18 Cultural Representation
	B7 Folk Beliefs	C19 Depth of Belief History
		C20 Degree of Public Participation
		C21 Social and Cultural Influence
	B8 Legal System	C22 Integrity of Systems
		C23 Social Adaptability
		C24 Inheritance of Rituals and Laws

).

5.3.2. Determining the Relative Weights of Indicators Using the AHP Approach

After establishing the system of evaluation indicators [53], the indicators were compared two by two by distributing expert questionnaires, constructing matrices and quantitative studies, as illustrated in

Table 6. Indicator weights of the evaluation index system of intangible spatial genes.

Target Layer	Criterion Layer	Weights	Evaluation Indicator Layer	Weights
A Evaluation of Intangible Spatial Genetics in Nihegou Village	B1 Folk Art	0.108	C1	0.557
			C2	0.320
			C3	0.122
	B2 Folktale	0.158	C4	0.297
			C5	0.539
			C6	0.163
	B3 Local Dialect	0.328	C7	0.594
			C8	0.276
			C9	0.128
	B4 Dietary Features	0.228	C10	0.309
			C11	0.109
			C12	0.581
	B5 Production Techniques	0.026	C13	0.216
			C14	0.102
			C15	0.681
	B6 Local Custom	0.070	C16	0.260
			C17	0.663
			C18	0.106
	B7 Folk Beliefs	0.042	C19	0.126
			C20	0.457
			C21	0.416
	B8 Legal System	0.037	C22	0.106
			C23	0.193
			C24	0.699

.

The AHP approach was employed to compute the weight values for the guideline and indicator layers [54]. To ensure the objectivity of results, eight experts were consulted, comprising specialists in the intangible cultural heritage of Nihegou Village, architectural experts, and members of Nihegou Village Cultural Preservation Committee. These individuals were selected due to their significant academic contributions and extensive practical experience in traditional village preservation and intangible cultural heritage. We conducted in-depth interviews and distributed structured questionnaires to collect their professional judgments, which were subsequently used to construct the judgment matrices for the AHP analysis. Based on the scoring results, the maximum eigenvalue ${\lambda }_{max}$ and eigenvector W of each matrix were calculated and a consistency test is performed. The results of expert scoring were sorted and counted, and the weight results of the evaluation index system of intangible spatial genes in Nihegou Village were determined using the AHP mathematical model in conjunction with Yahp10.3 software, as shown in Table 6.

5.3.3. Weight Analysis

In Table 6, the weight values of layers B and C reflect their share of data in the evaluation system. The guideline layer B is ranked in order of importance as Local Dialect > Dietary Features > Folktale > Folk art > Local Customs > Folk Beliefs > Legal System > Production Techniques. This shows the important position of local dialect in the intangible spatial genes of Nihegou Village. Among the evaluation indicators of the local dialect, the frequency of dialect use and the preservation status are in the top two places, which shows that the frequency of dialect use and the preservation status are the most important, and they are the key to the inheritance of intangible spatial genes in the village. In dietary characteristics, the order of importance of each evaluation index is Diversity of Diet > Social and Cultural Influence > Culinary Skills, which shows that in the evaluation of intangible spatial genes of Nihegou Village, the dietary characteristics and socio-cultural influence of Nihegou Village are the most important; and among the evaluation indices of folktales, the effectiveness of oral dissemination is the most important factor.

5.3.4. Fuzzy Evaluation Results and Analysis

Scoring data were obtained through questionnaire research. In September 2023, two rounds of random surveys were conducted in Nihegou Village (see Appendix A for details). A total of 206 questionnaires were distributed, and 197 valid responses were collected, achieving a response rate of 95.6%. The scores from the data and scoring criteria were weighted and converted into a composite score (

Table 7. Combined score for the criterion layer of non-physical spatial genes.

Index	Score	Ranking
B1 Folk Art	76.446	3
B2 Folktale	73.845	6
B3 Local Dialect	71.853	7
B4 Dietary Features	76.783	1
B5 Production Techniques	76.577	2
B6 Local Custom	76.076	5
B7 Folk Belief	76.302	4
B8 Legal System	65.496	8

and

Table 8. Combined score for the evaluation indicator layer of non-physical space genes.

Index	Score	Ranking	Index	Score	Ranking
C1 Historical Continuity	75.1	10	C13 Degree of Skill Preservation	77.4	6
C2 Artistic Creativity	79.1	1	C14 Ability for Skill Innovation	72.7	15
C3 Public Participation	75.7	9	C15 Economic and Practical Value	76.9	7
C4 Originality of Stories	74.7	12	C16 Degree of Custom Inheritance	70.9	21
C5 Effectiveness of Oral Communication	73.8	14	C17 Social Cohesion	77.8	5
C6 Cultural and Educational Value	72.4	17	C18 Cultural Representation	78.5	2
C7 Frequency of Use	71.5	20	C19 Depth of Belief History	72.3	18
C8 Status of Dialect Preservation	72.5	16	C20 Degree of Public Participation	78.5	3
C9 Mechanism of Language Inheritance	72.1	19	C21 Social and Cultural Influence	75.1	11
C10 Diversity of Diet	74.5	13	C22 Integrity of Systems	62.5	24
C11 Culinary Skills	76.7	8	C23 Social Adaptability	64.6	23
C12 Social and Cultural Influence	78	4	C24 Inheritance of Rituals and Laws	66.2	22

) that clearly reflects the current status of intangible spatial genetics in Nihegou Village.

According to the research, the preservation of dietary characteristics and production techniques has led both tourists and villagers to perceive that the social and cultural influence of dietary characteristics and the preservation of production skills are relatively high. However, other intangible cultural elements, such as local customs, folklore, and the etiquette system, have experienced significant adverse changes due to the complex market environment and diverse external pressures. The factors can be attributed to two aspects. First, due to the geographical influence, the water of the Junhui River in the village has been dry in recent years, resulting in a serious imbalance in the biosphere and environmental degradation. Nihegou Village has always had inconvenient transportation, with only one daily bus along the Yellow River Road and Futang Temple Mountain Road, and the village only has one bus trip per day, “going out early and returning late”. Second, as urban modernization accelerates, younger villagers often leave the village for work, showing less interest in local customs and traditional practices. This migration disrupts the intergenerational transmission of intangible cultural elements, such as orally transmitted folk tales and rituals. The population structure has changed, leaving behind children and elderly residents, which has further weakened the practice and transmission of cultural customs. The physical spaces associated with cultural practices, including sacrificial and belief spaces, have also deteriorated, as public buildings are poorly maintained and infrequent use for cultural activities. Consequently, the vitality of the village diminishes, impacting the stability and transmission of its intangible cultural genes.

6. Discussion and Conclusions

6.1. Discussion

Quantitative analysis indicates that the spatial layouts of traditional villages are shaped by factors such as the natural environment, scientific and technological progress, economic conditions, and traditional cultural influences. The concept of spatial genes functions as a foundational framework in this study, revealing the inherent laws and evolutionary processes of traditional village spatial structures. By quantifying these spatial genes, this research not only identifies the key elements influencing village morphology but also enhances the broader understanding of how traditional villages adapt to socio-economic changes over time.

(1)

The natural environment forms the foundation for the spatial form of traditional villages. The geographic features, water systems, and climate directly impact village site selection, layout, and architectural styles, and impose substantial constraints on regional socio-economic development and cultural formation. Nihegou Village is located on the periphery of the Loess Plateau, characterized by hills and ravines in its terrain. This unique natural environment dictates that village layouts predominantly follow valley contours, with most houses constructed on slopes, resulting in a spatial arrangement uniquely adapted to the loess plateau topography.

(2)

Scientific and technological advancements coupled with economic development significantly influence the spatial morphology of traditional villages. Technological progress opens new possibilities for village planning and development, resulting in more scientifically rational layouts that better adapt to environmental changes and meet residents’ needs. For example, the ancient jujube orchard irrigation system in Nihegou Village utilizes the Chehuigou water source, which optimizes water resource management and effectively improves the spatial layout of the village. Economically, the villagers primarily earn their livelihood from jujube cultivation and migrant labor, with reliance on traditional production methods and infrastructure somewhat limiting modernization and scale expansion of the village. Currently, Nihegou is actively exploring innovations, developing specialized agriculture and aquaculture to enrich the village cooperative’s projects and drive industrial upgrading. It is also vigorously developing the tertiary sector, enhancing rural tourism infrastructure and services to further promote comprehensive socio-economic development.

(3)

Traditional culture plays a pivotal role in shaping the spatial form of traditional villages. The traditional culture of Nihegou Village is reflected in the architectural style of the village, the living habits of the villagers and the way of celebrating traditional festivals. For example, most of the old houses in the village are traditional loess kilns with good heat preservation properties; every special festival in the Nihegou Jujube Forest still maintains the most ancient rituals (praying for blessings), such as the “Dajiao” ritual.

Previous research on spatial features focused on qualitative methods, describing and interpreting the spatial features of traditional villages through field surveys, literature reviews, or from the perspective of spatial semiotics [18,55]. In contrast, recent research has increasingly adopted quantitative methods to better understand the complex mechanisms underlying village morphology [56]. Although this transition is underway, there remains a significant lack of systematic studies in the literature that integrate quantitative analysis with the spatial genetics of traditional villages. This study addresses this gap by introducing the concept of “spatial genes” and emphasizing quantitative analysis. By prioritizing data collection and employing technical tools such as Geographic Information Systems (GIS) and spatial analysis, this research aims to quantitatively describe and identify patterns in village spatial forms, thereby delving into the generative mechanisms underlying spatial morphology and uncovering the inherent laws and evolutionary processes governing village spatial structures.

Additionally, this study highlights several key points. First, the concept of “spatial genes” draws on biological genetics, allowing for a more objective and precise quantification of village spatial data to reveal the characteristics and patterns of village spatial morphology. Second, by utilizing the FAHP evaluation method, it is possible to scientifically rank the impact weights of various factors [44], thereby more accurately identifying the key elements that influence village development. This method combines the advantages of qualitative and quantitative analyses, enhancing the rationality and adaptability of decision-making processes. Unlike traditional qualitative studies, our approach enables a detailed exploration of the relationships between the natural environment, technological advancements, intangible culture, and the spatial morphology of traditional villages. These factors shape the spatial genes of the village, ultimately influencing its spatial form.

Shaanxi Province, with its rich history and numerous traditional villages, faces significant challenges in preservation and of cultural heritage inheritance [57]. This study is limited by the researcher’s knowledge and capabilities. First, in theoretical terms, while it builds on existing research to propose novel solutions, its analysis remains superficial and its theoretical contributions require enhancement. Additionally, the research scope is relatively narrow, with a limited sample size. Future studies should expand the sample base to develop a more comprehensive theoretical framework that could better support the preservation and inheritance of traditional village landscape genes in Yulin City and throughout Shaanxi Province.

6.2. Conclusions

Table 9. Gene coding table of Nihegou Village.

Genomic Indicators	Gene Code	Parameter	Quantified Value
A Natural Environmental Genome	A1	Altitude	720~840 m
	A2	Slope	2°~25°
	A3	Slope Orientation	0.63
	A4	Hydrophilic	96.98 m
B Physical Space Genome	B1	Building	228
	B2	Village Boundary	1.74
	B3	Street	0.064
C Intangible Spatial Genome	C1	People’s Lives	74.16

presents the quantitative values of each spatial gene in Nihegou Village, identifying key spatial characteristics of traditional villages, including natural environment, architectural styles, and street patterns. These characteristics collectively constitute the unique essence of traditional villages. The findings provide a scientific basis for formulating strategies to protect and revitalize the village’s spatial features. Based on these quantitative values, we have proposed strategies for the preservation and transmission of spatial genes in Nihegou Village:

(1)

Cultural Project Login, Revitalizing Cultural Heritage

To effectively preserve and revitalize the cultural heritage of Nihegou Village, a comprehensive registration and archival process of its cultural projects is essential. By leveraging modern technologies such as AR and VR, the original memory data can be preserved, and the status of inheritance activities and the progress of cultural inheritors can be thoroughly documented. Creating a database allows for the digitization of these cultural assets, thereby facilitating broader dissemination and educational opportunities. Concurrently, cultural revitalization initiatives, including traditional festivals, handicraft workshops, and cultural lectures, will be launched, allowing both villagers and tourists to actively engage in cultural inheritance. This engagement will enhance their cultural identity and sense of belonging.

(2)

Preserve Architectural Style, Reorganize Spatial Functions

The spatial essence of Nihegou Village manifested not only in its cultural aspects but also in its architectural style and spatial layout. Preserving traditional architecture and maintaining its historical appearance are crucial for heritage conservation [58]. Modern preservation techniques should be employed to reinforce and restore old buildings while retaining their original charm. Building on this foundation, reorganizing spatial functions—by transforming certain traditional buildings into cultural exhibition halls, craft shops, or community centers—preserves these structures and simultaneously endows them with new social functions, creating mutual benefits for culture and economy.

(3)

Optimize Street and Alley Texture, Establish Orderly Guidance

Streets and alleys function as the basic units of spatial organization in villages, and their layout and form significantly impact the overall appearance of the village and the daily lives of its residents. By optimizing the design of streets and alleys, such as improving traffic layouts, adding green belts, and planning public spaces rationally, the living environment of the village can be enhanced, increasing the accessibility and comfort of the space. Furthermore, establishing an orderly guidance system, such as installing signage and interpretive panels introducing cultural history, not only facilitates tourist navigation but also promotes the dissemination and education of the village’s cultural heritage, deepening public understanding and awareness of Nihegou Village.

The implementation of these strategies can effectively protect and revitalize the spatial essence of Nihegou Village. This not only contributes to the preservation of its unique cultural characteristics but also supports the village’s sustainable development. Furthermore, these strategies for cultural heritage preservation, which balance respect for history with a forward-looking perspective, offer valuable insights for other villages possessing unique cultural and spatial qualities.