Cultural Diversity Conservation in Historic Districts via Spatial-Gene Perspectives: The Small Wild Goose Pagoda District, Xi’an

Abstract

The accelerating processes of globalization and modernization have imposed unprecedented anthropogenic pressures on the cultural diversity of historic districts, leading to the physical degradation of historical heritage and the fragmentation of cultural transmission chains. To address this challenge, this study establishes an innovative spatial-gene theoretical framework that seeks to balance heritage protection with urban development by integrating landscape characteristics and cultural connotations, thereby enhancing the conservation of cultural diversity in historic districts. Focusing on the historic Small Wild Goose Pagoda district as a case study, we developed a comprehensive methodology integrating field research, historical induction, spatial analysis, and place-making. Through this operational framework, we systematically identified four constitutive spatial genes: the mountain–water pattern, the urban-axis, the li-fang, and the architectural courtyard. These genetic elements inform a dual-regeneration strategy that promotes synergy and dialogue between old and new: (1) place-making guided by historical morphological grammar rules and (2) activity organization that reconfigures the value system of “openness and inclusiveness”. This research not only advances spatial-gene theory but also provides a replicable model for regenerating historic districts oriented toward cultural diversity, effectively combining historical authenticity with contemporary functionality to promote sustainable urban development.

1. Introduction

In the context of the global urban humanistic shift, cultural diversity has become a fundamental component of sustainable development [1,2]. The series of UNESCO documents—the 2001 Universal Declaration on Cultural Diversity, the 2005 Convention on the Protection and Promotion of the Diversity of Cultural Expressions, and the 2030 Agenda for Sustainable Development, adopted in 2015—have collectively established a robust theoretical framework for the conservation of cultural diversity. These documents underscore its strategic importance as a shared heritage of humanity and emphasize its multi-dimensional role in driving urban development [3,4].

As critical carriers for the conservation of cultural diversity [5,6,7], historic districts have undergone a three-stage evolution in their regeneration paradigms: from the conservation of heritage entities established by France’s Malraux Law in 1962, to the dynamic circular system theory proposed by the Beijing Charter in 1999, and finally to the “Historic Urban Landscape (HUL)” methodology introduced by UNESCO in 2011. This cognitive shift from individual preservation to organic renewal offers an innovative approach to balancing heritage protection with contemporary development, facilitating the functional transformation of historic districts from repositories of culture to incubators of diversity.

The core of the HUL approach lies in establishing the correlations among space, time, and perception by defining the historical evolution processes of spatial elements, thereby accurately identifying the characteristics of urban landscapes and their cultural values and providing more effective bases for urban planning and the design of historical heritage. However, due to the inadequacies of the HUL approach in explaining the internal causes of the evolution of spatial elements and the mapping relationships between spatial elements and cultural connotations, the outcome is often the disjunction between the shaping of spatial forms and the inheritance of historical culture, with spatial places and cultural activities being unconnected [8,9,10,11,12,13,14]. Therefore, finding a driving force that not only integrates the characteristics of urban landscapes and cultural connotations [15] but also establishes a balance between urban development and heritage protection [16] has become a key issue in the current regeneration of historic districts.

Duan et al. from Southeast University proposed the concept of spatial genes in 2019. This concept refers to the unique and relatively stable spatial-combination patterns formed by a city during its historical evolution. These replicable patterns carry the genetic information of the long-term interaction between urban space and social culture, and they dominate the expression of regional landscape characteristics and the formation of cultural places. They are considered to have the potential to be applied in the ongoing urban regeneration [17,18,19,20]. Based on the aforementioned theory, this research centers on the intrinsic correlation mechanism between the “spatial genes” and “cultural diversity” of historic districts and puts forward a core proposition: in the course of globalization and modernization, how can the decoding and translation of spatial genes be employed to realize the dynamic conservation of cultural diversity in the process of historic district regeneration?

The research subject of this study is the historic Small Wild Goose Pagoda district in Xi’an, a city recognized as the ancient capital of 13 dynasties in China. Through field research, multi-source historical material collection, and analytical techniques, including historical induction, spatial analysis, and cultural coding, this research identifies and interprets multi-scalar spatial genes inherent to the historic district. Subsequent exploration of the “space–culture” system’s interaction mechanisms under spatial genetic influences enabled heritage transmission analysis anchored in these genetic patterns. Consequently, a systematic framework for cultural diversity conservation within the historic district was formulated. This article seeks to advance spatial-gene theory, facilitate the development of heterogeneous spatial configurations and culturally rooted place identities, and establish an innovative paradigm for safeguarding cultural diversity during historic district regeneration processes.

This article comprises six major sections, beginning with an introduction that delineates the background, problems, and outline of the research. In the second section, the theoretical foundation of the research is introduced, concentrating on the background, core ideas, and main aspects of the concept of spatial genes. The third section presents the research topic and methods, with an emphasis on constructing a spatial-gene identification method based on the translation of multi-source historical materials, encompassing three steps: materials collection and storage, data analysis and clustering, and information condensation and coding. The subsequent two sections constitute the main body of this paper, depicting the identification results for the relevant spatial genes in the historic Small Wild Goose Pagoda district and the cultural diversity conservation framework based on the inheritance of spatial genes, respectively. Finally, this research concludes with the conclusion and research prospects.

2. Theoretical Basis

Spatial genes refer to unique and relatively stable spatial-combination patterns that emerge through the long-term interaction between urban space and social culture [17]. As a hereditary medium, spatial genes carry the evolutionary information of past periods’ alignment between urban space and social culture via constructive memory [21] and path dependence [22], thereby constraining the development of urban space and social culture in future periods. For instance, the spatial genes of Beijing’s Siheyuan are rooted in the Fangxiang system of the Yuan Dynasty. The courtyard layout, characterized by axial symmetry and hierarchical progression, was reinforced by the feudal clan and ritual systems of the Ming and Qing Dynasties, embodying Confucian ethical order. In contemporary urban construction, exemplified by Juer Hutong, the constraining elements of spatial genes—such as axes, gray spaces, and height differences between main and side rooms—continue to influence and shape the future humanistic and ecological patterns of the city.

The discourse on urban heredity initially emerged in the field of land economics in the late 20th century [23]. In 1986, Langton initially probed into the molecular logic in artificial life and proposed that cellular automata (CA) were key tools for achieving research progress [24]. Batty and Longley discerned a spontaneous rule in the process of urban growth, which determined how basic social spatial entities shaped the form and function of cities [25]. Inspired by Darwin’s theory of evolution, scholars began to study cities as complex adaptive systems and quasi-organisms, borrowing the core concept of genes from biological genetics [26,27]. They sought to capture the uniqueness and stability of urban development processes through genetic analogies, using specific indicators and parameters to achieve optimal urban development models and characteristics. In this context, Silva was among the first to propose the concept of regional DNA, defining it as key elements that constrain the operation of urban complex systems and potentially play a significant role in future regional development [28]. Wilson extended this perspective to the urban level, defining urban DNA as diverse combinations of multiple underlying structural variables capable of characterizing cities and explaining their morphological evolution. By identifying and adjusting these variables analogous to urban DNA, the state of the urban system can be planned and optimized [29]. Subsequently, Wu and Silva further categorized urban DNA into two aspects: material urban genes, which exhibit homology with morphological typology research, and immaterial urban genes [30]. D’Acci adopted a marginally different approach, exploring how urban planners could synthesize a genotype to balance the disparities in the spatial distribution of the benefits and negative externalities of urban agglomerations [31].

The discovery of spatial genes stemmed from the reflection on the two traditional research fields of morphological typology, namely, urban morphology and architectural typology. Conzen’s urban morphology emphasized understanding morphological units by capturing the morphological factors on the urban plane and tracking their changes from their initial formation to the present. He contended that the combination of morphological units at three hierarchical levels can exert a framing constraint on the current urban landscape [32]. Caniggia’s architectural typology initially distinguished between basic and special types of urban buildings and held that basic types replicated in space and time in two ways: synchronic variations and diachronic variations. Consequently, types permeate the formation process of the current urban landscape. On this basis, Caniggia proposed a design typology method centered on the leading type, arguing that through the reading and design operation of the leading type, the coordination and unity of new and old buildings and the urban texture can be accomplished [33].

Duan et al. asserted that, despite the considerable progress achieved in explaining the urban form process, traditional morphological typological research still constituted a closed system centered on the physical form of cities (particularly buildings). It regards various socio-economic and folk cultural changes as external factors of form variations, neglecting the counteractive force of the physical form on the socio-economy and folk culture and inadequately considering the future development of historical heritages. Nevertheless, a place with a clear urban context and diverse inclusiveness is of paramount importance for the fostering of new cultures [17]. The core of the spatial-gene concept lies in identifying the genetic factors that sustain the virtuous development of cities. Hence, in urban regeneration, what ought to be protected are not the landscape characteristics or cultural activities but the spatial-combination patterns carrying the genetic information of the city. These are key to evoking public historical and cultural memories in Gestalt psychology. Under the control of spatial genes, landscape characteristics and cultural activities can vary along with changes in people’s production and lifestyle, and this process encompasses the potential for cultural innovation and development, as well as the acceptance of future urban functions.

The inheritance mechanism of spatial genes can be described from three aspects: coding, replication, and expression. First and foremost, spatial genes are encoded by spatial elements of varying scales in accordance with certain rules, presenting a stable spatial-configuration relationship and reflecting profound cultural connotative information. For example, the urban-axis genes in ancient China encompass thoughts such as harmony between humans and nature, the supremacy of the center, and the ritual system. Secondly, spatial-gene information is replicated through dissemination in both synchronic and diachronic dimensions, thereby manifesting the characteristics of a specific group within a particular time and space range. Herein, synchronic dissemination refers to the generation of the same spatial-combination pattern in different regions during the same period, while diachronic dissemination refers to the generation of the same spatial-combination pattern in the same region at different times, similar to the replication process of biological genes. Finally, through the synergy of multiple genes, spatial loci reflect recognizable urban personalities and characteristics and carry abundant social and cultural activities with local imprints [34].

3. Research Subject and Methodology

3.1. Overview of the Historic Small Wild Goose Pagoda District in Xi’an

Xi’an, situated in the hinterland of China, is an ancient capital with a history of being a capital city for over a thousand years, spanning 13 dynasties. It boasts an extremely rich array of historical and cultural heritages, such as the Terracotta Warriors and Horses, Huaqing Pool, the Great Wild Goose Pagoda, and the Small Wild Goose Pagoda. Among these, the Small Wild Goose Pagoda, a Tang Dynasty Buddhist architectural heritage, was listed in one of the first batches of key national cultural relic protection units and was inscribed on the UNESCO World Heritage List in 2014 as a site of the “Silk Road: Chang’an—Tianshan Corridor Route Network”.

The historic Small Wild Goose Pagoda district is situated in the central area of Xi’an, with a total area of approximately 42 hectares. There are multiple historical relics remaining, such as the Tang Dynasty’s Small Wild Goose Pagoda, Zhuque Avenue, Jianfu Temple, Anren Fang, the Seventh Transverse Street, and the Ming and Qing Dynasties’ ancient buildings. Moreover, there are a considerable number of ancient and famous trees, and it is also the location of the Xi’an Museum. Its convenient geographical position, abundant cultural resources, and distinctive urban landscape made the historic Small Wild Goose Pagoda district a core area for the activities of citizens in all dynasties. This indicates that it has great potential for cultural diversity protection and promotion (Figure 1).

3.2. Research Methods

This study adopts a critical realist research paradigm to investigate the interplay between spatial morphology and cultural diversity in the historic district. Grounded in David Harvey’s conceptualization of space as a social construct shaped by the dialectical relationship between material practices and symbolic meanings [35], this paradigm integrates Conzen’s emphasis on structural permanence in urban morphology [32] with Caniggia’s typological analysis of diachronic architectural evolution [33]. It further extends these frameworks through the theory of spatial genes [17]. By combining quantitative geospatial analytics with qualitative hermeneutic techniques, this approach identifies materially encoded spatial invariants (genes) and interprets their mutable socio-cultural expressions across temporal strata.

3.2.1. Field Research

The public participation method advocated by field research is beneficial for the in-depth description, interpretation, evaluation, and design of historic districts, which serves as a prerequisite for cultural diversity conservation [36]. Through intermittent visits spanning half a year, we comprehensively collected both physical and non-physical materials from the historic Small Wild Goose Pagoda district, offering detailed data support for the subsequent identification of spatial genes and analysis of cultural diversity. Conducting small-sample on-site interviews with local residents 2~3 times per month in 2024 and integrating 1064 Weibo posts geolocated at the Small Wild Goose Pagoda from 2019 to 2024, we developed more accurate demographic profiles and public perception insights. This approach provides a multi-dimensional perspective for interpreting spatial genes and formulating urban regeneration strategies. Meanwhile, since the historic district is influenced by the spatial genes of a broader area, we extended the scope of on-site research to the entire historical urban area of Xi’an, investigating its urban morphology and social and cultural characteristics at different development stages, laying a solid foundation for research on spatial genes.

3.2.2. The Method of Spatial-Gene Identification

The principles of integrity and authenticity proposed in the Venice Charter are fundamental requirements for spatial-gene identification. As characteristic spatial-combination patterns accumulated layer by layer in the urban historical process, the diachronicity of intergenerational transmission and the synchronicity of multiple juxtapositions of spatial genes constitute important references for their research. To address confusion regarding spatial genes in the diachronic dimension, we have combined the identification of spatial genes with the collection of historical materials from different periods, fully considering the complex processes of the generation, iteration, and inheritance of spatial genes, and formulated a spatial-gene identification method based on the translation of historical materials. This method enables more accurate identification of spatial genes through three operational steps: “materials collection and storage”, “data analysis and clustering”, and “information condensation and coding” (Figure 2).

(1) Materials Collection and Storage

Rich and reliable historical materials are conducive to a comprehensive understanding of the patterns of spatial genes existing within the spatiotemporal domain. In accordance with the urban spatial hierarchy system, ranging from macro to micro, the information utilized for the identification of spatial genes can be categorized as follows: (a) natural environment information, such as geographical location, climatic conditions, and mountain–water patterns; (b) historical information, including the history of ancient urban construction and significant historical events; (c) urban structural information, including functional organization, neighborhood layout, road traffic networks, and important public spaces; (d) detailed urban information, such as building complexes, gardens, and courtyards; and (e) life scene information, such as residents’ lives, social customs, and traditional festivals. Information acquisition channels encompass but are not limited to historical documents, historical mappings, stone inscriptions, oral history, cultural relics and archaeological materials, poetry, and folk proverbs. In the process of selecting and using historical materials, certain principles should be followed. Firstly, priority should be given to using first-hand historical materials to ensure the authenticity and accuracy of historical events. Secondly, the selected historical materials should be verified or recognized by experts, avoiding reliance on unconfirmed single evidence. Meanwhile, it is imperative to adhere to the principle of relying solely on evidence. A dual-evidence approach that integrates both archaeological findings and literary records should be employed to authenticate the reliability of historical sources.

Considering that the majority of historical materials are attached to printed materials such as books and newspapers, optical character recognition technology was employed to digitize the text and images within historical materials and transform them into a form readable by computers. Specifically, (a) text data exhibit substantial volume with high readability. During processing, textual materials undergo initial cleansing to eliminate extraneous content, followed by segmentation into lexical units or phrases. Subsequent phases involve cultural connotation identification through information extraction, keyword distillation with symbolic representation, and ultimate storage of structured data in relational databases. (b) Image data possess strong visual interpretability but are susceptible to tampering and standardization deficiencies. The preprocessing pipeline incorporates OpenCV-based image acquisition, dimensional scaling with cropping, landmark feature extraction, and grayscaling coupled with quantization, culminating in pixel value normalization for digital image generation. (c) Geographic data require geometric rectification via ArcGIS post-imaging processing. This entails geospatial coordinate system alignment, topographic feature extraction (e.g., thoroughfares, hydrographic elements, and buildings), vector conversion with attribute enrichment, and final archival in standardized formats, including Shapefile and GeoJSON (Figure 3).

(2) Data Analysis and Clustering

The core knowledge ontology of spatial genes is the spatial-combination pattern. Taking the urban-axis gene as an example, there exist remarkable disparities between Western countries and China in the spatial-combination patterns composed of variables like the location, system, orientation, void-solidity, and primary–secondary urban axes. Urban axes in Western countries typically present a form of multi-directional radial extension, with open spaces as the core and buildings on both sides in parallel, whereas urban axes in China mainly adopt an orthogonal system, with building complexes as the core, progressing layer by layer, forming a strict and orderly spatial layout. The acquisition of its information necessitates a series of spatial analysis approaches. In this respect, traditional morphological typology research has amassed abundant analysis methods, such as element analysis, structural analysis, network analysis, etc., which can analyze the explicit characteristics of urban space from both two-dimensional planes and three-dimensional aspects. When there are multiple research objects, it is necessary to investigate the stability of explicit characteristics through cluster analysis and classify spatial elements and their configuration relationships to achieve the effective extraction of spatial-combination patterns (Figure 4).

(3) Information Condensation and Coding

The crux of spatial-gene identification lies in achieving the knowledge construction of spatial genes through specific data, namely, abstracting the identification framework of spatial genes into several relatively explicit norms and explanations. Based on the exposition of the concept of spatial genes by Duan et al. [17], the identification framework mainly encompasses the following four parts:

(a) Gene name: serving as an accurate description of a spatial gene, the gene name represents the basic elemental composition or spatial organizational object of spatial genes in textual form.

(b) Index scene: employed to describe the spatiotemporal coordinates of typical historical scenes where spatial genes are identified, this is of paramount importance for comprehending the origin and formation conditions of spatial genes.

(c) Morphological characterization: this involves describing the urban morphological characteristics generated under the control of spatial genes, typically described by multiple interrelated morphological indicators.

(d) Cultural connotation: the theory of spatial genes posits that space and culture constitute an inseparable unified entity. Hence, it is necessary to utilize a “space–culture” interactive system to reveal the cultural metaphors and values behind the morphological characteristics.

Given the prominent cluster characteristics and systematic correlations of spatial genes in specific regions, holistic encoding of this multi-dimensional interactive information can not only effectively deconstruct the complex context emerging under the backdrop of spatiotemporal superposition but also facilitate systematic cognition and precise positioning of the spatial-gene map. Based on the storage paradigms and invocation mechanisms in database construction, we employ four symbols to represent gene name, index scene, morphological characterization, and cultural connotation, establishing a spatial-gene information coding sequence of “English letters + Arabic numerals”. On this foundation, we have constructed a spatial-gene database with dynamic update capabilities using Python 3.3. This database adopts a NoSQL architecture for unstructured data storage and utilizes the Django framework to build a RESTful API interface, ensuring efficient retrieval and intelligent analysis of multi-source heterogeneous spatial-gene data (Figure 5).

3.3. Research Procedure

This research employs the aforementioned methods and is categorized into four primary phases:

(1) Collection and processing of historical materials. Seven types of historical materials of the historic Small Wild Goose Pagoda district and Xi’an historical urban area were gathered: (a) historical maps; (b) satellite images; (c) research literature; (d) ancient literary and poetry; (e) local chronicles; (f) archaeological discoveries; and (g) ancient paintings (

Table 1. Collection of multi-source historical materials for Xi’an.

Material Category	Examples of Historical Materials	Source	Data Format
Historical maps	The Map of Chang’an by Lü Dafang (the Song Dynasty) The Map of Chang’an by Li Yuanhao (the Yuan Dynasty) The Eight Scenic Spots Map of Guanzhong by Zhu Jiyi (the Qing Dynasty)	Stone tablet rubbings Historical books	Image data Geographic data
Satellite images	Google Earth Satellite Images (1980–2024)	Network	Image data
Research literature	Re-examination of Planning Methods for the Li-Fang in Sui and Tang Chang’an Analysis of Internal Forms in Tang Chang’an’s Li-fang	CNKI Database (Total of 548 articles)	Textual data Image data
Ancient literary and poetry	Early Spring Presented to Water Department’s Zhang Eighteen, an Official by Han Yu Staying at the New Residence of Mr. He, a Scholar of the Previous Generation, in Yanfu by Zhao Xia Climbing Guanyin Terrace to View the City by Bai Juyi	Complete Poems of the Tang Dynasty Collection of Chang’an Collection of Sanqin (Total of 420 related poems)	Textual data
Local chronicles	Chronicles of Chang’an by Li Yuanhao (the Yuan Dynasty) Examination of the Two Capital Cities in the Tang Dynasty by Xu Song (the Qing Dynasty)	Historical books	Textual data
Archaeological discoveries	Brief Record of Archaeology in Tang Chang’an Archaeological Discoveries at the Wuqiao Site in Anrenfang	Archaeological research	Textual data Image data
Ancient paintings	Snowy Scene in the Capital Region by Li Sixun (the Tang Dynasty) Dragon Pool Racing by Li Zhaodao (the Tang Dynasty)	Art collections	Image data

). These materials were processed in diverse formats, such as geographic, textual, and image data, which were stored in geographic, Microsoft Access, and Open Image Dataset databases, respectively.

(2) Analysis of spatial-configuration relationships. Qualitative and quantitative analyses of the spatial-configuration relationships in the historical data were carried out by employing methods such as element analysis based on semantic segmentation, structural analysis based on Depthmap1.0 software, and network analysis based on ROSTCM6 software. The specific analysis contents comprise landscape patterns, urban forms, alignment relations between urban and landscape elements, road network structures, block shapes and tissue, and combinations of buildings and courtyards. Through these analyses, the high-dimensional urban genetic morphemes, semantics, and grammatical information contained in multi-source heterogeneous data such as vector models, text semantics, and raster images were converted into low-dimensional data.

(3) Data clustering and space–culture interaction analysis. Spatial elements and morphological characterization clusters with potential correlations were identified via cluster analysis of the dataset. The corresponding relationships between morphological characterization and cultural connotation were established via space–culture interaction analysis. The identification results were classified into four levels: region, city, block, and building. Each level encompassed contents such as gene names, index scenes, morphological characterizations, and cultural connotations. Finally, the spatial-gene coding database of the historic Small Wild Goose Pagoda district was created.

(4) Spatial-gene inheritance and regeneration strategies for the historic district. The conformance of the identified spatial genes to the future development requirements of the city was evaluated. On this basis, with the aim of perpetuating or restoring these spatial-combination patterns by designing the living environment and cultural scenes at different scales, we put forward regeneration strategies for the historic Small Wild Goose Pagoda district based on spatial-gene inheritance, providing fertile soil for the breeding of diverse cultural manifestations. Ultimately, a qualitative assessment of cultural diversity was conducted to evaluate the changes before and after the historic district regeneration.

4. Results

4.1. Historical and Current Characteristics of the Historic Small Wild Goose Pagoda District

The historic Small Wild Goose Pagoda district has undergone three ups and downs. It not only records the urban memories of the rise and fall of different dynasties but also constitutes an important historical coordinate in the transformation of the urban pattern.

The Small Wild Goose Pagoda was initially constructed during the Tang Dynasty and was primarily utilized for storing Buddhist scriptures and conducting Buddhist activities. During the wars at the end of the Tang Dynasty, the Jianfu Temple sustained severe damage, with the monks scattering and the temple falling into ruin. In the Song Dynasty, due to severe weathering, devout believers undertook large-scale renovations of the Small Wild Goose Pagoda, restoring its eaves and corners and coating it with white soil, conferring a semblance of revival to the pagoda. After the Song Dynasty, the Jianfu Temple gradually fell into disuse during the Jin and Yuan Dynasties, with only the brick pagoda remaining. During the Ming and Qing Dynasties, the Jianfu Temple and the Small Wild Goose Pagoda underwent numerous renovations and became the examination venue for martial arts candidates in the provincial examinations in Shaanxi Province. There was a saying that “academic questions were set at the Great Wild Goose Pagoda, while martial questions were set at the Small Wild Goose Pagoda”. During the Republic of China period, the Small Wild Goose Pagoda once again declined due to wars, and the Jianfu Temple was occupied by the military for an extended period, with the Buddha statues being damaged. In 1961, the Small Wild Goose Pagoda was proclaimed as one of the first batches of key national cultural relic protection units by the State Council of China. In 2007, the Xi’an Museum, whose establishment relied on the Small Wild Goose Pagoda and the Jianfu Temple, emerged as a comprehensive venue integrating cultural relic collection, scientific research, social education, and garden leisure. On 22 June 2014, the Small Wild Goose Pagoda was inscribed on the WHL (Figure 6 and Figure 7).

The historic Small Wild Goose Pagoda district has gradually evolved from a prosperous urban core to an old urban area that is not in harmony with its surroundings. The main problems it confronts are as follows:

(a) The historical pattern within the region has been disrupted. High building density, poor housing quality, and disorderly landscape features have led to a severe waste of cultural resources.

(b) Although adjacent to several landmarks, such as the Xi’an CBD, Xi’an Museum, and Shaanxi Provincial Stadium, the district suffers from insufficient infrastructure and a poor street walking experience, failing to achieve effective joint development with the surroundings.

(c) The district currently comprises approximately 1700 households, characterized by a diverse demographic composition and a wide range of stakeholders. Public perceptions of the historic district’s current state and future preferences exhibit considerable variation (Figure 8). In addition, the built environment includes a variety of structures, such as urban villages, terraced houses, villas, office buildings, military compounds, and flower markets.

Thus, due to problems such as cultural loss, district deterioration, and interwoven interests, the regeneration of the historic Small Wild Goose Pagoda district is confronted with numerous challenges.

4.2. Identification of Relevant Spatial Genes of the Historic Small Wild Goose Pagoda District

Given the distinctive natural environment and cultural ambience, the historical urban area of Xi’an has offered a significant foundation for the perpetuation of the cultural context of the historic Small Wild Goose Pagoda district and integrated it into a multi-dimensional and multi-scale spatial-gene pool [37]. We utilized the spatial-gene identification method derived from the interpretation of historical materials to systematically organize the spatial and cultural characteristics of Xi’an across various historical periods. Comparative analyses were also conducted with Beijing and Nanjing, two other prominent ancient capitals of China, to identify commonalities and distinctions (

Table 2. The comparative analysis of urban form among Xi’an, Beijing, and Nanjing.

Spatial Hierarchy	Description	Xi’an	Beijing	Nanjing
Region	Integrating natural topography and water systems into urban design to create harmonious ecological and aesthetic landscapes.
		Xi’an (Ming Dynasty)	Beijing (Ming Dynasty)	Nanjing (Ming Dynasty)
		Classical, harmonious	Balanced, steady	Flexible
City	Serving as connectors for transportation, culture, and community activities.	Xi’an (Tang Dynasty)	Beijing (Ming Dynasty)	Nanjing (Ming Dynasty)
		Symmetric, orderly	Symmetric, imposing	Partly, parallel
Block	Reflecting the social and spatial structure of communities and their relationship to public spaces.
		Qinren Fang (Tang Dynasty)	Dashilar (Ming Dynasty)	Confucius Temple (Ming Dynasty)
		Orderly, orthotropic	Densely, organic	Free-form, organic
Building	Representing privacy, hierarchy, and the interplay between indoor and outdoor spaces.
		Guanzhong-residential house (Ming Dynasty)	Siheyuan (Qing Dynasty)	Wufenglou (Qing Dynasty)
		Enclosed, narrow	Modular, regularized	Densely, atrium-like

). Based on these findings, we defined gene names, determined their index scenes, and summarized the morphological characterizations and cultural connotations expressed by spatial genes. Ultimately, through systematic gene coding, we established a robust knowledge base for the conservation of cultural diversity in historic district regeneration.

4.2.1. Gene Names

Based on the results of analyzing the historical materials and in accordance with the spatial hierarchical system, ranging from region, city, and block to building, we have categorized the spatial genes associated with the historic Small Wild Goose Pagoda district into four major types: the mountain–water pattern gene, urban-axis gene, li-fang gene, and architectural courtyard gene. The specific classifications are as follows:

(a) Mountain–water pattern gene: comprising spatial elements such as settlements, mountains, rivers, city walls, and urban centers and encompassing sub-genes such as the form of city walls, the relationship between the city and the landscape environment, and the correspondence between urban construction and topography.

(b) Urban-axis gene: incorporating spatial elements such as landmarks, squares, roads, green spaces, and building clusters and covering sub-genes such as the sequential structure of axes, the axis system, and its virtual–real relationship.

(c) Li-fang gene: encompassing spatial elements such as buildings, streets, plots, street furniture, and plants and covering sub-genes such as the structure of the road network, the height–width ratio of streets, and the figure–ground relationship of blocks.

(d) Architectural courtyard gene: consisting of spatial elements such as doors, windows, walls, rooms, roofs, and courtyards and covering sub-genes such as the configuration relationship of buildings, the length–width ratio of courtyards, and the window–wall ratio of facades (Figure 9).

4.2.2. Index Scenes

The most representative index scene of Xi’an is the splendid landscape pattern constituted by the city and the surrounding mountain and water environments in different historical periods. Taking Xi’an City of the Sui and Tang Dynasties as an example, the city was situated in the midst of the extensive plain between the Qinling Mountains and the Wei River. From the Daming Palace and the Small Wild Goose Pagoda to Zhongnan Mountain, a majestic development context was formed. The eight rivers, namely, Wei, Jing, Ba, Chan, Feng, Lao, Yu, and Hao, constituted the urban water network pattern of “Eight Rivers Surrounding Chang’an”. The imperial and palace cities were located at the center of the northern part of the city. Important buildings such as the Small Wild Goose Pagoda occupied the advantageous terrain of six terraces, embodying the urban layout characteristic of “The North Star occupies its position while all the other stars encircle it”.

The second index scene is Zhuque Avenue of the Tang Dynasty, which traverses the palace city, imperial city, and outer city. It was 8000 m in length and 130 m in width, making it the widest street in the city. This central axis endowed the entire city with a distinctive form of “contracted in the north and expansive in the south”. The main buildings in the palace city were situated on the elevated area of Longshouyuan at the northern end. The government institutions of the imperial city were symmetrically arrayed on both sides of Zhuque Avenue. The significant public buildings and religious sites of the outer city (such as the Small Wild Goose Pagoda and Jianfu Temple) were distributed along both sides of Zhuque Avenue toward the east and west. The southern end of the central axis extended all the way to Zhongnan Mountain.

The third index scene is Anren Fang in the Tang Dynasty. It measured 560 m in length and 540 m in width, approximately square. Within it, there were 17 religious and residential buildings, constituting a basic unit complex of urban planning and residential management. During the Sui and Tang Dynasties, a grid-like road system was employed in the city, dividing the city into numerous li-fangs of varying sizes, creating an orderly layout pattern resembling a chessboard. As an inward-oriented block enclosed by fang walls, Anren Fang was divided into four sub-areas by a cross street with lanes and alleys.

The fourth index scene features multiple traditional quadrangle courtyards represented at the micro level in different dynasties. Traditional residential buildings in Xi’an typically formed long, narrow quadrangle courtyards extending from north to south with solid walls and open interiors, as houses were constructed around the perimeter; alternatively, three-sided courtyards were created by houses on three sides, enclosing one side with a wall and a gate. Regarding the functional layout, the main hall and bedrooms were toward the south, the entrance hall was toward the north, and side chambers were on both sides. In terms of architectural form, there were numerous detailed characteristics, such as pitched roofs, overhanging eaves, vertical lattice windows, black-headed gates, and platforms.

4.2.3. Morphological Characterizations

Mountains, rivers, and terraces collectively constituted natural barriers and significant references for the historical urban construction of Xi’an. The Tang Dynasty’s Xi’an City was situated on the northern side of Zhongnan Mountain and encompassed three rivers. The distances between these natural elements and the city were all regulated at approximately 20 km, thereby achieving the construction of the “first landscape” from the interior to the exterior. The longitudinal deviation between the eastern city wall and Zhongnan Mountain and the deviation between the western city wall and Ziwu Valley were both controlled within 0.1 degrees, falling within the visual error range, thereby verifying the orientation relationships between urban construction and mountains. The relationships were likewise manifested in the urban construction of the Qin and Han Dynasties. Additionally, the length–width ratios of the city walls during different periods consistently ranged between 1:0.8 and 1:1.3, and the urban form approximated a square, which aligned with the description of the ideal urban form in “Record of Artisans” in The Rites of Zhou.

The characteristics of the urban-axis gene were mainly manifested in the urban spatial order and traffic organization constructed by axis elements. We calculated the axis control coefficient of the historical urban area of Xi’an (the ratio of the axis length to the urban perimeter) and found that its value ranged from 0.21 to 0.27, which was much higher than those of Suzhou (0.13), Hangzhou (0.08) in the Song Dynasty, and Nanjing (0.11) in the Ming Dynasty. This indicated that the axis had stronger control over the spatial layout of Xi’an. Through the selective analysis of the spatial syntax of the road network of Xi’an in the Tang Dynasty, within the range of 5000 m for travel choices, Zhuque Avenue, as the transportation hub of the entire city, presented a traffic organization characteristic that gradually weakened from the axis to the periphery. According to an analysis of the correlation between the axial distance and the plot area, as the distance of the plot from the axis decreased, the ratio of the actual plot area to the ideal plot area also decreased, which implied that the closer the plot was to the axis, the denser the road network, the higher the traffic accessibility, and the more diverse the functions.

The li-fang gene of Xi’an in the Tang Dynasty manifested the morphological characteristics of “inward aggregation into wards and outward expansion into streets”. The width of urban roads exceeded 40 m, and the height of the ward walls was 2–3 m, which divided the city into 108 chessboard-like and interconnected wards. The 16 m-wide cross street divided the ward into four sections. The degree of spatial organization of this street was significantly higher than others; thus, it could be determined that it was the most public area in the entire ward. According to relevant archaeological discoveries, there was a certain mathematical arrangement rule for the residential land area within the wards: the residential land area was divided according to the residents’ social status hierarchy, and the overall distribution followed the ratio principle of 1:2:4:8, presenting obvious self-similarity and a recursive structure.

Buildings within the historical urban area of Xi’an were distributed in an organic and nested manner. Through a cluster analysis based on their configurational relationship, the buildings can be categorized into four subtypes: single-line type, L-shaped type, U-shaped type, and courtyard type. Influenced by climatic conditions such as strong winds, low rainfall, and intense sunlight, the width–length ratio of the courtyard typically ranged from 1:3 to 1:4, and the height–width ratio of the courtyard cross-section was approximately 1:1. To withstand sandstorms and retain warmth, thick earthen walls were employed, and the proportion of windows to the wall surface was controlled within 25%. Additionally, roof designs have evolved over time. Although the specific roof forms in different eras may have varied slightly, they generally maintained a roof slope ranging from 25° to 35° and a height-to-span ratio ranging from 1:3 to 1:5 (Figure 10).

4.2.4. Cultural Connotations

Through research on the space–culture interactive system, we have summarized the cultural connotations of spatial genes into the following four aspects: conforming to the cosmic conditions, adapting to geographical circumstances, abiding by the ritual system, and adhering to the people-oriented principle.

As anthropologist Kwang-chih Chang stated in 1999, the ancient Chinese civilization “was formed within an integrated cosmic theoretical framework” [38], and this continuity between humans and the universe permeated multiple aspects of the historical urban construction of Xi’an. The strategy of “designing the capital to imitate the heaven” in the Qin Dynasty and the “Dipper City” in the Han Dynasty both manifested the realistic cosmic ideology bestowed by heaven. As significant communication media between heaven and Earth, mountains and rivers bestowed special symbolic significance on the historical urban construction. For example, the planning of Xi’an City in the Sui and Tang Dynasties was influenced by the view toward Mount Zhongnan and the worship of mountains and rivers; the relationships between Xi’an City and Mount Cuo’e in the Qin Dynasty and between Xi’an City and Mount Longshou in the Han Dynasty also reflected this notion.

The “Theory of Geographical Advantage” in ancient Chinese urban construction ideology profoundly impacted the urban spatial layout and architectural space organization of Xi’an. In the Sui and Tang Dynasties, five canals were excavated in Xi’an based on the eight major water systems, such as the Wei River, Jing River, and Feng River. These canals were distributed in all areas of the capital, enabling the imperial city, palace city, and most residential areas to benefit from them. For instance, the canal on the northwest side of the Small Wild Goose Pagoda not only satisfied the demands of water supply and drainage for the city but also offered the residents of Anren Fang a beautiful waterfront activity space with pleasant scenery. Furthermore, when planning Xi’an City during the Sui Dynasty, Yuwen Kai surveyed six terraces spanning the north and south of the city and placed important buildings, such as Buddhist temples and Taoist abbeys, at the undulating parts of the terraces, thereby fully exploiting the natural terrain conducive to living and public activities. The Jianfu Temple, where the Small Wild Goose Pagoda was situated, served as one such instance.

The historical urban construction of Xi’an has consistently emphasized adherence to a moderate sense of a ritual system, specifically, “the vessel conceals the ritual”. In accordance with the ritual standards of The Rites of Zhou and Records of the Grand Historian, a central axis plane layout was formed: the central axis passing through the Small Wild Goose Pagoda and leading to the Daming Palace was a crucial element advocating the political orthodoxy related to the urban form. The imperial city, palace city, and li-fang areas had distinct functional divisions and hierarchical regulations, reflecting the disparities among social classes. In architectural design, an ancient dictum stated, “The hall of the emperor is nine feet high, that of the vassals is seven feet high, that of the ministers is five feet high, and that of the scholars is three feet high”. The strict hierarchical system stipulated by the ritual system determined the size, proportion, and appearance of the buildings.

The evolution of spatial genes was closely intertwined with the development of the commodity economy and corresponding market management adjustments. During the early Tang Dynasty, the government implemented a centralized market system characterized by strictly regulated operating hours (morning opening/evening closure) and administrative control over market establishment, relocation, and dissolution. However, population growth and rapid commercialization prompted the gradual relaxation of spatiotemporal market controls. This deregulation led to the emergence of “special market zones”—government-sanctioned trading areas permitted under exceptional circumstances. By the mid-to-late Tang period, the proliferation of these high-frequency trading zones signaled a fundamental spatial-economic shift from neighborhood-based periodic markets to permanent street-market configurations.

4.2.5. Gene Coding

Through the aforementioned research on gene names, index scenes, morphological characterizations, and cultural connotations, we have established a spatial-gene coding table for the historic Small Wild Goose Pagoda district. This coding table is composed of 16 symbols, specifically encompassing four-digit codes for gene names, four-digit codes for index scenes, four-digit codes for morphological characterizations, and four-digit codes for cultural connotations (Figure 11). No item of information in the coding table exists in isolation; rather, by combining these four types of codes, a complete set of spatial-gene entry information is formed. This enables planners and managers to precisely grasp the genetic information related to the historic district and avoid phenomena such as the misreading, misunderstanding, and misusing of spatial genes in the regeneration of the historic district.

5. Discussion

5.1. Analysis of the Relationship Between Spatial Genes and the Conservation of Cultural Diversity in the Historic Small Wild Goose Pagoda District

Amid the collision of global cultures and accelerated urban development, urban cultural diversity faces unprecedented challenges and opportunities. Spatial genes, as significant carriers of urban culture, play a crucial role in this process. Observations indicate that the spatial genes of many cities have undergone mutations, leading to more complex urban forms and cultural expressions. This phenomenon has sparked discussions on cultural diversity: Can urban forms remain recognizable after alterations in spatial genes? Does urban culture truly reflect diversity?

By conducting a comparative analysis of the Beijing CCTV Headquarters, designed by Rem Koolhaas, and the Suzhou Museum, designed by I. M. Pei, we can gain a clearer understanding of the influence of spatial genes on urban cultural diversity within the context of globalization. The design of the Beijing CCTV Headquarters disrupts the traditional spatial-gene sequence of Chinese architecture. Its contorted shape and cantilevered structure contravene the aesthetic principle of axial symmetry and the hierarchical order of “superior above and inferior below” in traditional Chinese architecture. This genetic mutation renders the building an isolated symbol divorced from the local cultural context. Although innovative and distinctive in form, it is difficult to be regarded as a representative of Beijing’s local culture and evoke public cultural resonance, thereby failing to effectively uphold cultural diversity. In contrast, the design of the Suzhou Museum employs an ingenious “gene decoding recombination” approach, converting classic elements such as framing techniques and alleyway scales from traditional Chinese gardens into modern parameters. By preserving the traditional spatial genes of Suzhou, it achieves a fusion of traditional and modern styles, infusing new vitality into the urban culture. During this process, spatial genes, through their unique spatial-combination patterns, carry information regarding the survival and development of ancestors in a specific period [34], ensuring the uniqueness and exclusivity of the derived culture and thereby enriching the diversity of world culture.

Consequently, we argue that spatial genes can play a pivotal role in the conservation of cultural diversity within the historic Small Wild Goose Pagoda district, primarily through their influence on material carriers and cultural cores.

(1) Cultural diversity manifests in various forms of material culture, including regional heritage and resource utilization. To interpret the cultural diversity within the historic Small Wild Goose Pagoda district, it is essential to ground this interpretation in specific material cultural forms. For instance, the 108 li-fang grids of Tang Chang’an City can be transformed into the organizational logic of the street and alley texture. By applying historical morphological grammar rules, the historical spatial codes can be converted into a readable cultural narrative, thereby preserving Xi’an’s regional characteristics and making the historic district an area that is easily perceivable and memorable [39].

(2) The traditional cultural connotation plays a pivotal role in the conservation of cultural diversity. The core of the regeneration efforts in the historic Small Wild Goose Pagoda district lies in understanding and intervening based on a cross-value system. As Pye posits, cultural connotation refers to the meanings and values embedded in material objects, providing a substantive foundation for the protection of historical heritage [37,40]. By transmitting the historical, political, and cultural information encoded in Xi’an’s spatial genes—such as the principles of ritual systems, the philosophy of harmony between humans and nature, and people-oriented values—and by reconstructing an “open and inclusive” value system, we can enrich and modernize traditional culture [26,41].

It is imperative to underscore that integrating humanistic innovation into the process of inheriting the spatial genes of the historic Small Wild Goose Pagoda district holds critical significance [42]. The inheritance of spatial genes does not imply cultural regression or stagnation in the past; rather, it entails leveraging the cultural connotations embedded within these spatial genes as a foundational premise for conservation. By creating diversified cultural scenarios that cater to the usage demands of stakeholders and providing a conducive “container” for the incubation of new cultural activities, this approach ultimately fosters a sense of cultural fulfillment and satisfaction among the public.

It is observed that the Great Wild Goose Pagoda, also a World Heritage Site, has successfully integrated the cultural legacy of the flourishing Tang Dynasty into modern culture through the preservation of its heritage pattern, texture, and landscape. Adopting an inclusive and open approach, it has fostered numerous distinctive cultural IPs, such as the Tang Dynasty Ever-Bright City, Journey to the West, and The Twelve Hours of Chang’an, thereby showcasing the historical vitality and contemporary dynamism of this ancient capital. In cultural diversity conservation, the spatial layout defined by elements like squares, axes, and landmarks remains traditional, while architectural forms, colors, and functions are modernized. This juxtaposition creates cultural spaces with high degrees of inclusiveness and openness, allowing for the coexistence of traditional elements—such as Hanfu, poetry, and dance—and modern symbols—like street art, light shows, and advertisements—thereby facilitating a harmonious dialogue between old and new (Figure 12).

5.2. Analysis of the Regeneration of the Historic Small Wild Goose Pagoda District Based on Spatial-Gene Inheritance

5.2.1. Taking the Inheritance of Spatial Genes as the Objective of Historic District Regeneration

The regeneration of the historic Small Wild Goose Pagoda district is aimed at inheriting the identified genes of the mountain–river pattern, urban-axis, li-fang, and architectural courtyard and comprehensively and systematically presenting the grand story of cultural development. Proceeding from the notion of “reestablishing the dialogue between old and new”, we carried out low-intervention order reconstruction guided by spatial genes on four research scales: region, urban, block, and building [43]. Through the construction of spatial order based on traditional thoughts and values, such as conforming to cosmic conditions, adapting to geographical circumstances, abiding by the ritual system, and adhering to people-oriented principles, the new and old spatial elements can coexist harmoniously in threatening activities and buildings and provide social spaces and cultural services for the public [44,45], thereby generating diverse cultural manifestations (Figure 13 and Figure 14).

5.2.2. The Regeneration of the Historic District Based on Spatial-Gene Inheritance

(1) The Inheritance of the Mountain–Water Pattern Gene

Establishing a visual connection between the core area and specific mountains is an important tradition of the ancient Chinese cities represented by Xi’an, reflecting the cultural connotations of “receiving the mandate from heaven” and “mountain worship”. On the one hand, as a World Heritage Site, the Small Wild Goose Pagoda has requirements for authenticity and integrity [46]. The strict protection of its landmark not only enhances the regional cultural identity of urban residents but also promotes the perception of urban characteristics [47]. On the other hand, the Small Wild Goose Pagoda is located in the core urban area. Zhuque Avenue to its east was the central axis of Xi’an City in the Tang Dynasty, and Chang’an Road to its west is the central axis of modern Xi’an. The Jianfu Temple, where the Small Wild Goose Pagoda is located, has always maintained a central axis layout. Protecting the overall visual corridor formed by these three axes is the key to inheriting the mountain–water pattern gene. By delimiting the visual impact area, controlling the building height within the area, ensuring that the line of sight from the viewpoint (the Small Wild Goose Pagoda) to the landscape (the ridge line of Mount Zhongnan) is unobstructed, and organizing the foreground (public activities), middle ground (traditional style buildings), and background (mountain forms), a visually undisturbed human activity scene can be formed, vividly showcasing Xi’an’s landscape and urban environment.

Furthermore, the drainage facilities discovered at the junction of the ruins of Zhuque Avenue and the wall of Anren Fang were once a component of the urban water system in the Tang Dynasty, which offers an opportunity for the historic Small Wild Goose Pagoda district to highlight the city’s water culture. By restoring the course of the water system in the northwest of the district and transforming the shape of the water surface and the public space around the shorelines, a Water Theater, with the water surface as the foreground and the stage as the background, can be created. Additionally, by introducing artistic performances with themes from the historical stories of the Tang Dynasty, the historical memory of the “Eight Rivers Encircling Chang’an” can be evoked among citizens. Considering that the terrace area has always been the most vibrant part of Xi’an City and there is a terrace traversing the district, this area is positioned as a public activity congregation zone with themes of Tang and Silk Road culture. Within this area, citizens can utilize the undulating terrain to hold festivals or large-scale cultural activities (Figure 15). It can be asserted that both of the aforementioned measures were inspired by the “Theory of Geographical Advantage” within the spatial genes of Xi’an.

(2) The Inheritance of the Urban-Axis Gene

In the Tang Dynasty, Xi’an City was divided into eastern and western parts along the central axis. As the most crucial structural element in the magnificent spatial pattern, Zhuque Avenue embodied the unique ritual ideology exclusive to ancient China. Nevertheless, Zhuque Avenue no longer exists today. Only a few historical relics have been discovered around the Mingde Gate and the Small Wild Goose Pagoda site, such as the site of the five parallel bridges located in the northwest corner of Anren Fang, which was selected as one of the six major archaeological discoveries in Shaanxi Province in 2022. Hence, the protection and utilization of the Zhuque Avenue site and the urban heritage corridor where it is located are of paramount significance for inheriting the historical context of the city [48].

Since the Zhuque Avenue site has been severely disrupted by urban construction and it is challenging to implement systematic and comprehensive protection, we have divided it into three sections for separate transformation—northern, middle, and southern—and have incorporated cultural activities with the theme of the ritual system. The specific measures are as follows: (a) The northern section: Based on the site of the five parallel bridges, a Zhuque Avenue site museum will be established. Through a display of unearthed cultural relics, such as roads, canals, bridge sites, wall foundations, gate sites, culverts, and wells, the history of urban planning and construction, including the ritual system of the capital city, the road arrangement, the layout of residential blocks, the bridge structure, and artificial canals, will be presented. (b) The middle section: A dedicated 3D experience area for Zhuque Avenue will be set up in the Xi’an Museum. The historical images of the Zhuque Avenue site will be generated, and digital technology will be utilized to create an immersive browsing area and cultural scene with a distinct theme. (c) The southern section: A 130 m-wide thematic park will be created, with the landscape features, building volume, height, and color on both sides being guided. Meanwhile, memorial sculptures, small-scale artworks, and other landscape elements will be set up to showcase the historical life scenes of Zhuque Avenue through physical space [49] (

Table 3. The regeneration approaches of Zhuque Avenue.

Urban-Axis Gene	Regeneration Procedure	Overall Layout
	Current Situation Analysis
	Improvement Strategies
	Node Settings
	Public Activities

).

(3) The Inheritance of the Li-Fang Gene

The li-fang was the fundamental unit of urban planning and management in Xi’an during the Tang Dynasty, and the historic Small Wild Goose Pagoda district precisely constitutes the optimal area for presenting this distinctive cultural manifestation. In light of the archaeological excavation of the Anren Fang site, we discovered that the district once formed a standardized li-fang configuration with Anren Fang as the main body (that is, the internal space of the li-fang was partitioned by three road levels: cross streets, lanes, and alleys), and we are contemplating promoting the district regeneration through walkability [50] (

Table 4. The regeneration approaches of the district through walkability.

Road Level	Spatial Configuration	Spatial Design	Design Strategy
Cross Streets			The two 16 m-wide streets are extended, dividing the entire historic district into four basic units, namely, the northwest, northeast, southeast, and southwest, and thereby shaping the landscape axes.
Lanes			The spatial scale of the lanes is controlled in accordance with the requirement for a 1:1 street height–width ratio, forming a street environment conducive to public interaction.
Alleys			For various functional urban interfaces, distinct street design strategies are employed to shape the Genius Loci.

).

(a) Cross Streets: The Spatial Framework of Anren Fang

We have perpetuated the spatial-combination pattern of the li-fang with the cross streets, dividing the district into four sectors through two 16 m-wide streets. Considering the current demographic characteristics and the perceptual imagery of each sector, the specific functional layout is meticulously planned as follows: The northwest sector, which includes the Small Wild Goose Pagoda Ruins and Xi’an Museum, is dedicated to preserving cultural heritage through conservation efforts and facility upgrades. This approach ensures that citizens can visit, tour, and engage in historical learning. The northeast sector comprises a commercial complex and commercial street, primarily featuring ordinary restaurants and daily food services for tourists, thereby enhancing the vibrancy of the historic district [51]. The southeast sector encompasses high-end hotels, serviced apartments, and commercial apartments, fostering the development of the nascent night economy and transforming the district into a 24 h dynamic area [52]. The southwest sector hosts four thematic cultural exhibition halls, which organize cultural exhibition activities on weekdays and holidays, providing a platform for the government and civil society organizations to showcase various forms of cultural manifestations (

Table 5. The regeneration approaches of the four sectors.

Section	Cultural Activities	Spatial Generation	Planar Layout	Urban Image
The northwest sector	Historical study, Buddhist debate, cultural relic exhibition, etc.
The northeast sector	Premium dining, business street, etc.
The southeast sector	Night-time economy, hotel lodging, etc.
The southwest sector	Cultural display, design studio, tourism and sightseeing, etc.

).

(b) Lanes: The Main Pedestrian Spaces and Cultural Activity Venues

We controlled the spatial scale of the lanes in accordance with the morphological characteristic of a li-fang with a height–width ratio of 1:1, thereby forming a spatial environment suitable for walking. Meanwhile, by integrating urban interfaces with diverse functions, we create a wide range of cultural activities, such as lantern appreciation, street performances, Hanfu shows, and creative markets [53]. The novelty of the design lies in extending the pedestrian range and opening up the original closed interface, enabling cultural buildings to no longer be in a confined state. Instead, through the arrangement of landscape elements such as doors, windows, and sculptures, more extensive spatial connections are generated [54].

(c) Alleys: Capillary-shaped Pedestrian Network

Alleys constitute the highest proportion of the entire road system. Their preservation and reuse have instilled new vitality into the historic district [55]. We adopted disparate alley-design strategies for urban interfaces with varying functions, such as augmenting portal spaces, offering recreational facilities, and installing landscape ornaments, to intensify the sense of spatial retention and belonging and stimulate citizens and tourists to delicately taste and profoundly ponder the historical culture.

(4) The Inheritance of the Architectural Courtyard Gene

The architectural courtyards convey the artistic, aesthetic, and cultural information of a specific historical period through their distinct morphological characteristics and Genius Loci [56]. Absorbing and inheriting these architectural–configurational relations, preserving historical information and integrating it into new urban development, and making it a cultural memory space that carries the daily lives of the people and establishes emotional connections among residents are important endeavors on the architectural scale for the regeneration of the historic Small Wild Goose Pagoda district.

Firstly, based on the ratio principle of 1:2:4:8 of traditional residential courtyards, the spatial scales of architectural courtyards are effectively controlled. Secondly, the morphological characteristics of traditional architecture are perpetuated. Historical elements are extracted from both material and intangible cultural heritages and applied to the place-making and activity organization of the historic district through semantic translations rooted in local culture [57] (Figure 16). For instance, the height–width ratio of the courtyard cross-section is approximately 1:1, and the height-to-span ratio of the building ranges from 1:3 to 1:5. Meanwhile, cultural characteristics such as Tang Tri-color Glazed Pottery, shadow puppetry, and woodblock New Year pictures [58], as well as architectural components such as doors, windows, plinths, and brackets, are incorporated into the design guidelines [59].

Finally, each architectural unit is reconfigured to form single-line, L-shaped, U-shaped, and courtyard type cultural edifices, such as the Li-fang Cultural Museum, the Silk Road Cultural Museum, and the Small Wild Goose Pagoda Tourist Service Center. This creates a relaxing and pleasant venue atmosphere for people in the bustling urban area. In terms of activity content, it is developed into a new urban cultural space dominated by the display, experience, and dissemination of cultural and artistic works, further enhancing citizens’ sense of identification with historical culture (Figure 17 and Figure 18).

5.2.3. The Assessment of Cultural Diversity in the Historic Small Wild Goose Pagoda District

Based on the adaptability of cultural demands before and after the planning of the historic Small Wild Goose Pagoda district, we have established a cultural diversity assessment system. This system takes cultural activities, community participation, heritage utilization, cultural identity, and cultural and creative industries as the core dimensions, with standardized evaluation indicators set beneath each dimension for systematic analysis.

The pre-planning assessment indicated that although the activation of cultural heritage was remarkable, it was constrained by physical space limitations, presenting structural contradictions such as the homogeneity of cultural activities, the low level of community participation, the singularity of cultural identity expression channels, and the imbalance between supply and demand of space for the cultural and creative industry. After spatial reconfiguration, the cultural carrying capacity of the new composite venues has been significantly enhanced, supporting three types of new cultural activities (tea ceremony classrooms, cultural performances, and bazaar markets). Community participation has been elevated (including meetings and discussions, workshops, surveys, and volunteer activities), and the channels for expressing cultural identity have expanded to three mixed forms. Through the cultural and creative incubation space, a chain synergy effect has been formed, achieving the protection and promotion of cultural diversity (

Table 6. The assessment of cultural diversity in the historic Small Wild Goose Pagoda district.

Dimension	Indicator	Pre-Planning Assessment *	Post-Planning Assessment *
Cultural activities	VR historical scene restoration	+	++
	Academy lectures	+	+++
	Tea ceremony classrooms	+	++
	Cultural performances	+	+++
	Bazaar markets	+	+++
Community participation	Meetings and discussions	ο	+
		ο	++
		ο	+
	Workshops	+	+++
	Surveys
	Volunteering activities
Heritage utilization	Museums	++	+++
	Cultural heritage exhibition halls	+	+++
	Relic parks	+++	+++
Cultural identity	Language and dialects	+	++
	Art and handicrafts	ο	++
	Architectural styles	+	+++
Cultural and creative industries	Hanfu clothing	+	+++
	Film and television	ο	++
	Photography	++	+++
	Galleries	ο	+

* ο: None; +: Emergent; ++: Institutionalized; +++: Hegemonic.

).

6. Conclusions

6.1. Integrated Findings and Contributions

The conservation of cultural diversity constitutes a significant component of sustainable urban development in the 21st century and a key issue that needs to be resolved in the regeneration practice of historic districts. Over the past decade, although the widely utilized HUL method has established correlations among space, time, and perception and is capable of accurately identifying the landscape features and cultural values of urban heritage, it has deficiencies in explaining the internal causes of the evolution of spatial elements and appears helpless when confronted with a large number of heritage structures, living heritage, and unofficial heritage with cultural value. Considering that spatial genes carry the hereditary information of long-term interactions between urban space and culture and dominate the expression of regional landscape features and the formation of cultural venues, we selected the historic Small Wild Goose Pagoda district in Xi’an as the research object and employed the spatial-gene inheritance method to create diverse places and culturally rooted activities, offering solutions for preserving cultural diversity in historic districts. The integrated findings and contributions of this study are as follows:

(1) The precise identification of spatial genes can be supported through the translation of historical materials.

This paper introduces a spatial-gene identification approach based on the translation of multi-source historical materials. Among them, materials collection and storage offer sufficient and mutually verified raw data, data analysis and clustering acquire low-dimensional spatial data and high-dimensional urban genetic information, and information condensation and coding realize the construction of spatial-gene knowledge ontology and digital management. This approach effectively remedies the insufficiency of traditional methods in the diachronic dimension positioning, fulfills the requirements for the precise and complete identification of spatial genes, and possesses the capability to explain the interactive evolution laws of space and culture. Furthermore, the three-tiered decoding process—from morphological analysis to type clustering and then to cultural interpretation—aligns with UNESCO’s guidelines on value-based conservation. This process establishes a replicable workflow for the contemporary interpretation of historical heritage, enhancing its applicability across diverse contexts.

(2) Spatial genes offer the basic rules for the morphological formation and cultural cultivation of historic districts.

Taking the historic Small Wild Goose Pagoda district in Xi’an as the research object, we systematically collated historical materials such as historical maps, ancient poetry and prose, and local chronicles. We identified four major gene types, namely, the mountain–water pattern, urban axis, li-fang, and architectural courtyard genes, and clarified the index scenes necessary for extracting these spatial-combination patterns. Through multiple indicators and data, the morphological characterizations of the spatial-combination patterns were reflected, and the cultural connotations behind them were explored. Unlike the traditional protection and utilization approaches for material and intangible heritages, the above conclusions situate the historical Small Wild Goose Pagoda district within a broader historical context and provide fundamental rules for the morphological formation and cultural cultivation of non-heritage areas. This framework illustrates how region-specific elements can coexist with universal urban spatial genes, demonstrating its potential for application in other historic districts facing context disruption.

(3) Historic districts demand the shaping of characteristic cultural scenarios featuring a coordinated dialogue between old and new.

Historical heritage is not immutable but is embedded in the human settlement environment and development context of historic districts. Through the inheritance of spatial genes, the cultural connotations of the historic Small Wild Goose Pagoda district are preserved, while modern cultural activities are subtly introduced to fill traditional spaces, creating a characteristic cultural scene featuring a coordinated dialogue between old and new. This conception involves utilizing spatial genes as a low-intervention approach to reconfigure the spatial order and reestablish the relationships between historic districts and the city, cultural relics, nature, and people, transforming historic districts from areas that were originally minimally utilized into spaces with profound culture and places of great inclusiveness, achieving certain development while protecting cultural diversity. It provides a robust and adaptable analytical framework that can adjust parameters according to specific cultural contexts while adhering to the principles of spatial genes. This framework offers flexible reference models for the regeneration practices of other historic districts facing similar challenges.

6.2. Limitations

However, it should also be acknowledged that this paper still presents certain research limitations:

Firstly, different cities possess varying historical remnants and differences in their reserves of cultural and historical data. The endowment of historical and cultural resources in many cities is not as abundant as that in Xi’an. Hence, the spatial-gene identification method based on the translation of historical materials still requires continuous adjustment and optimization. We propose that by integrating multi-source data, including remote sensing imagery, geological exploration, and oral history, and by referencing urban spatial-gene models from geographically or functionally analogous areas, the evolutionary process of spatial genes in regions with limited historical records can be systematically reconstructed. This approach aims to minimize potential misinterpretations of spatial genes due to fragmented data.

Secondly, although the regeneration of historic districts has facilitated tourism development and promoted cultural dissemination, it might also result in the degradation of the ecological and historical landscapes. Additionally, behaviors such as increasing investment, renovating historical buildings, and providing infrastructure to attract newcomers in the regeneration of historic districts are typical features of gentrification. Considering that the regeneration of historic districts is merely a means, while the conservation of cultural diversity is the objective, a comprehensive evaluation of multiple factors is necessary for the regeneration of historic districts.

Thirdly, the preferences of citizens and tourists for public spaces in historic districts can reflect whether cultural elements meet the development requirements of the city. The assessment of public perception factors in the regeneration of historic districts can be enhanced through the application of big data and artificial intelligence tools. For example, public aesthetic perceptions of architectural forms can be quantified using Flickr’s geo-tagged photo datasets, whereas societal engagement with cultural activities may be evaluated through Weibo’s location-based check-in records. Furthermore, multi-platform social media analytics (e.g., Instagram stories and X timelines) offer multi-dimensional perspectives on collective spatial cognition patterns.

6.3. Future Research Directions

We contend that future research orientations encompass the following aspects:

(1) Investigating more precise mapping regulations between spatial-gene information and historical materials

An in-depth exploration of the specific approaches for translating each category of historical materials into spatial genes is necessary to mitigate the difficulty of ontological association resulting from information reduction during the process of spatial-gene identification. Through the establishment of more precise mapping regulations, the accuracy and completeness of spatial-gene identification can be improved. Furthermore, the utilization of 3D models and interactive maps is proposed to enhance the presentation and interpretation of spatial-gene analysis.

(2) Applying spatial-gene theory in non-Chinese contexts

Although this framework is grounded in the context of the historic Small Wild Goose Pagoda district, it exhibits inherent transferability. Future implementations should calibrate the spatial-gene identification threshold using historical typologies from diverse global contexts. Establishing a non-profit spatial-gene data-sharing platform would facilitate the global dissemination of fundamental datasets, analytical approaches, and research outcomes among scholars. This initiative would not only enhance cross-validation among different spatial-gene datasets through systematic supplementation but also advance the conservation of cultural-spatial diversity on a global scale.

(3) Assessing the long-term performance of historic district regeneration

A systematic assessment of long-term performance in historic district regeneration, coupled with a diagnostic analysis of its spatial-gene characteristics, will reveal shortcomings in current revitalization strategies. These findings establish an empirical basis for refining conservation approaches while providing actionable recommendations for enhancing future interventions.

(4) Employing spatial genes to direct site design and building restoration

The application of spatial genes in historic districts establishes a theoretical framework for guiding site design and building restoration. This approach would preserve historical and cultural features while addressing modern functional requirements, achieving harmonious micro-level integration between heritage conservation and contemporary interventions.

We are confident that, through the collaborative efforts of scholars, the theory and methodology of spatial genes can be continuously refined. This will enhance the conservation of cultural diversity in historic districts and ultimately contribute to the sustainable development of global cities in the 21st century.