Spatial Distribution and Typological Classification of Heritage Buildings in Southern China

Abstract

Heritage buildings are a crucial aspect of a country’s cultural heritage, serving as a means of preserving and passing down its history and traditions to future generations. The heritage buildings in southern China possess significant conservation, utilization, and research value. However, research is lacking on the spatial distribution characteristics and subdivision types of these buildings in the region. This study aimed to investigate the spatial agglomeration and distribution characteristics of heritage buildings in southern China, as well as the factors contributing to the formation of these spatial distribution patterns. This article focused on the protection of 981 heritage buildings in southern China since the founding of China. The study examined the buildings’ spatial agglomeration and distribution characteristics from various dynasties and subdivided types. It utilized the average nearest neighbor analysis, unbalance index, and kernel density estimation to analyze this distribution. Additionally, this study also investigated the primary factors influencing the spatial distribution and differentiation of these buildings. The results demonstrated the following: (1) In general, the spatial distribution of heritage buildings in southern China is characterized by unevenness and clustering, with a concentration in the eastern coastal and Sichuan provinces. (2) In terms of temporal dimension, the spatial distribution of heritage buildings exhibits unique characteristics in various dynastic zones. (3) In the type dimension, the number of different types of heritage buildings varies greatly. (4) Further analysis of the distribution and types of heritage buildings indicates that quantitative differences are primarily influenced by natural, human, and socio-economic factors. This research was unique as it explored the geospatial distribution characteristics and determinants of heritage buildings. It offers a valuable perspective on the spatial distribution of heritage buildings and can serve as a reference for future studies on the preservation and protection of such buildings in China. Additionally, the findings can provide guidance for the management and rational use of heritage buildings in southern China.

1. Introduction

Heritage architecture is a valuable heritage left behind by previous generations, representing the crystallization of ancient engineering construction techniques, architectural engineering art, and the creative wisdom of ancient working people. It serves as a witness to ancient historical changes and holds extremely rich historical, cultural, and artistic research values [1]. As protected objects, heritage buildings are a form of material and spiritual wealth of mankind [2]. They possess multi-dimensional research values, including artistic aesthetic value, historical and cultural value, tourism value, and architectural technology reference value [3,4,5,6,7,8]. The southern region of China boasts a wealth of heritage buildings, encompassing a variety of architectural styles such as Huizhou style architecture [9], Hakka architecture [10,11], and Suzhou-style architecture [12]. Not only are these styles unique and representative of the region, but they also convey rich historical, technical, and cultural information [8]. Therefore, conducting research on heritage buildings in southern China holds great significance.

Current research in the field of heritage buildings is primarily focused on four key areas. First, the conservation and restoration of such buildings have yielded abundant research results. Systemic approach [13], building information models [14], 3D LiDAR, and multi-technology collaboration [15] are among the methods that aid in the conservation of these structures. Materials such as organic–inorganic hybrid sol [16] and lime-based mortars [17] have also proven to be effective in the restoration of heritage buildings. Second, with regard to heritage buildings and tourism development, Nuryanti proposed that heritage buildings are integral to cultural tourism [18], while Martha et al. suggested that combining these structures with cultural activities is key to promoting tourism development [19]. Moreover, Wang et al. analyzed the impact of tourism activities on heritage buildings [20]. Third, various countries and regions have made active attempts to incorporate heritage buildings into their modern urban planning systems. Italy, Britain, France, and Norway are among the countries that have carried out practices in this regard [21,22,23]. Fourth, the study of architectural models dominates the aspect of the structure of single heritage buildings. For instance, Angelini et al. conducted a 3D modeling of the patriarchal cathedral of the Patriarchal Basilica of Santa Maria Assunta in Aquileia [24] and Jiang et al. conducted a survey to develop an architectural information model of the cultural heritage of the Yingxian Wood Pagoda [25]. Similarly, Vranich reconstructed the building called Pumapunku at the site of the ruins of Tiwanaku (A.D. 500–950), in the modern republic of Bolivia [26]. However, research is lacking on the spatial distribution of heritage buildings at the macroscopic scale and large regional level. The spatial distribution of these buildings is influenced by both natural geography, such as climate change, topography, and river hydrology, and human factors, such as changes in administrative systems, ideological evolution, and socio-economic development [27]. These buildings are often found in clusters. The fertile rivers and plains of the Middle East, India, China, and Europe have historically been the birthplace of some of the world’s greatest civilizations. Today, heritage buildings can be found in Europe, America, Asia, the Pacific, and Arab countries, with a concentration in the eastern and northern coastal areas of Central and Western Europe [28]. The distribution of these heritage buildings offers valuable insights into local geography and historical and cultural systems [29]. Analyzing the distribution characteristics of China’s heritage buildings can provide a macroscopic understanding of their architectural features.

The temporal and spatial characteristics, spatial layout, and functions of heritage buildings undergo gradual changes during different periods of development, influenced by national history, cultural background, and regional characteristics [30,31]. These changes are reflected in the time of completion and building types, which are represented spatially by the number of buildings in different periods and the coupling of the number of different types of buildings with space and time [32]. To achieve a refined and differentiated conservation and use of heritage buildings in southern China, it is important to understand their distribution characteristics based on two perspectives, namely time of completion and building type.

China boasts a wealth of heritage buildings [33]. In October 2019, the National Cultural Heritage Administration of China (NCHA) announced 8 batches of 5060 key cultural relic protection units in China, of which 2169 were heritage buildings accounting for 42.87% of the total. These heritage buildings serve as crucial material foundation for showcasing traditional culture and promoting cultural tourism in various regions. China has implemented several measures to preserve and protect heritage buildings [34]. These measures include involving the community in conservation efforts [35], improving legislation for conservation and management [36], and utilizing modern technology [37]. However, there is a lack of research examining the regional spatial distribution of heritage buildings, which could aid in promoting their conservation.

This study aimed to analyze the differences in the spatial distribution characteristics of cultural relics and buildings from different periods and types and clarify the spatial clustering and distribution characteristics of heritage buildings in southern China. Additionally, this study aimed to identify the factors contributing to the differences in spatial distribution characteristics and the variety of types of heritage buildings. This study examined the spatial differentiation, distribution characteristics, and types of heritage buildings in southern China, based on data from the first eight batches of key cultural relic protection units in China published by the National Cultural Heritage Administration (NCHA) in October 2019. Specifically, this study analyzed the distribution of heritage buildings in general and in different periods and the quantitative differences between different types of heritage buildings. Finally, it analyzed the reasons influencing differences in the distributions and types of heritage buildings. This study analyzed the spatial characteristics of the distribution of heritage buildings and their spatial relationships on a macro scale, in contrast to previous architectural studies that have been dominated by the micro scale of individual buildings, with less attention paid to the macroscopic spatial distribution of heritage buildings. Furthermore, it clarified the basic resources of heritage buildings in terms of their practical value, which was conducive to the rational allocation and arrangement of resources by the conservation and management departments of heritage buildings.

2. Data and Methods

2.1. Study Area and Data Sources

2.1.1. Southern Region Overview

The southern China region comprises 15 provinces and cities, namely, Jiangsu, Anhui, Zhejiang, Hunan, Hubei, Sichuan, Yunnan, Guizhou, Guangdong, Guangxi, Fujian, Jiangxi, Hainan, Shanghai, and Chongqing (Figure 1). Data for Hong Kong, Macau, and Taiwan were not collected in this study. The region is located between 3–35° N latitude and 108–123° E longitude. Most of the provinces and cities in southern China are situated south of the Qinling and Huai Rivers. The region is characterized by a complex and diverse topography, which includes plateaus, mountains, basins, hills, and plains. The Yangtze and Pearl Rivers flow through this area.

2.1.2. Research Data and Sources

The research data on heritage buildings used in this paper were obtained from the National Cultural Heritage Administration (NCHA) of China of the National Key Cultural Relics Protection Units, specifically from the first eight batches of the National Key Cultural Relics Protection Units as of October 2019. The latitude and longitude of the Chinese heritage buildings were obtained by extracting the location information from Baidu Maps. Cultural heritage was classified as follows: monuments (e.g., paintings, sculptures, architectural and archaeological works, inscriptions, etc.); groups of buildings (e.g., separated or connected buildings with a value for architecture, homogeneity, or place in the landscape); “sites” (e.g., works of man or combined works of nature and man, and archaeological sites) [38]. The way in which this cultural heritage was classified provided an important reference for the classification of heritage buildings in this study. In the “Chai Zejun Ancient Architecture Anthology”, heritage buildings were classified according to their function. This classification system was combined with the main function and nature of use of southern heritage buildings. As a result, southern heritage buildings were classified into 12 categories (

Table 1. Heritage building types and components.

Type	Component
Palace building	imperial palace, yamen, temple, mansion house, etc.
Defensive building	battlement, bunker, pass, fire beacon, city hall, the Great Wall, etc.
Monumental building	belfry, drum tower, marble pillar, memorial arch, etc.
Garden architecture	The Royal Park, yard, villa, etc.
Sacrificial architecture	temple of Confucius, martial temple, ancestral hall, altar, etc.
Water building	bridge, dam, ditch, harbor, marina, etc.
Residential architecture	house, hall, courtyard, thatched cottage, etc.
Religious building	Buddhist temple, pagoda, Daoist temple, mosque, church, etc.
Civic architecture	tearoom, drama stage, dance pavilion, etc.
Mausoleum building	stone fault, stone archway, graveyard, stone carving, sacrificial altar, etc.
Social architecture	provincial or county guild hall, post station, etc.
Productive building	workshop, atelier, barn, storeroom, plant, etc.

): palace building, defensive building, monumental building, garden architecture, sacrificial architecture, water building, residential architecture, religious building, civic architecture, mausoleum building, social architecture, and productive building. After data processing, a total of 981 southern heritage buildings were collected. The data were disaggregated and a total of 981 southern heritage buildings were recorded.

2.2. Research Methods

2.2.1. Average Nearest Neighbor Analysis

The average nearest neighbor analysis is most suitable for comparing elements of different periods in a fixed study area. It can be used to determine the average distance of heritage building sites of the different periods in southern China and the spatial distribution characteristics of heritage building sites (aggregated distribution, random distribution, and dispersed distribution) based on the ratio R of the average observed nearest neighbor value (di) to the average expected nearest neighbor value (de). Therefore, in this study, the researchers utilized the average nearest neighbor analysis to determine the spatial distribution type of southern heritage buildings. Additionally, the researchers calculated the proximity value of each heritage building point element in the study area. The spatial distribution type of the point elements was classified into three categories: aggregated distribution (R < 1), random distribution (R = 1), and dispersed distribution (R > 1). The nearest neighbor index R was used to calculate the spatial distribution type; its formula is shown below:

$$R=\frac{\overline{r_i}}{r_E}=2\sqrt{D{r}_i}$$

(1)

where $\overline{r_i}$ is calculated as the average distance between neighbouring points of the heritage buildings and $r_E$ represents the average distance of the heritage buildings in the random distribution model. The density of the heritage buildings is denoted by D.

Its standard deviation Z value is expressed as [39]:

$$Z=\frac{\left(d_i-d_e \right)\sqrt{N^2/A}}{0.26136}$$

(2)

In the formula, the significance p-value is smaller when the Z-value is too high (strongly dispersed) or too low (strongly aggregated). When p > 0.1, the significance is poor and the heritage building sites are randomly distributed. When p < 0.01, the heritage building sites are strongly aggregated (or dispersed); 0.01 < p < 0.05 is a strong aggregated (dispersed) distribution and 0.05 < p < 0.1 is a general aggregated (dispersed) distribution.

2.2.2. Kernel Density Estimation

Kernel density estimation is a modern statistical analysis method for non-parametric density estimation commonly used in geography to analyze spatial patterns. The kernel density estimation method based on ArcGIS can be used to assess the spatial density of a certain phenomenon in a certain area and show the distribution pattern of spatial phenomena more intuitively. Therefore, in this study, kernel density estimation can be used to analyze the spatial distribution pattern and aggregation characteristics of southern heritage buildings. The density around the sample points can be estimated based on the density of the heritage buildings in the unit grid and produce a smooth surface [40]. The kernel density value reflects both the overall distribution characteristics of heritage buildings and the distribution characteristics of heritage buildings from different dynasties. A higher kernel density value indicates a denser distribution of heritage building points. The formula for kernel density estimation is as follows [41]:

$$f_n\left(x\right)=\frac{1}{\mathit{nh}}\sum _{i=1}^{n}k\left(\frac{x-X_i}{h}\right)$$

(3)

where f(x) is the estimated kernel density of heritage buildings; H > 0 is a preset radius; n is the number of heritage building points, 981 in total; (x − X_i) is the distance from valuation point x to event X_i, where the larger the kernel density value the more clustered the distribution of heritage buildings in the characterized area; h is the bandwidth (i.e., the search radius of the kernel density function); K(x) is the quadratic kernel function of spatial weights, K > 0.

2.2.3. Unbalance Index

The unbalance index can reflect the balanced distribution of heritage buildings in southern China and is calculated as follows:

$$S=\frac{{\sum }_{i=1}^n{Y}_i-50\left(n+1\right)}{100n-50\left(n+1\right)}$$

(4)

The formula for calculating the unbalance index of heritage buildings in the southern region takes into account the number of southern provinces and regions (n), the proportion of the number of heritage buildings in each province and city to the total number of heritage buildings in the whole southern region (Y_i), and the cumulative percentage of the i-th place in the ranking from largest to smallest. The resulting value of S ranges from 0 to 1. If S = 1, it means that the heritage buildings are concentrated in one province; if S = 0, it means that the heritage buildings are evenly distributed in each province [42].

3. Results and Analysis

3.1. Divergent Characteristics of the Spatial Dimension

3.1.1. Overall Spatial Agglomeration Distribution Characteristics

The average nearest neighbor analysis can also be used to determine the average distance and spatial distribution characteristics (aggregated distribution, random distribution, and dispersed distribution) of heritage building sites in southern China. Through the use of the average nearest neighbor analysis in ArcGIS10.7 software (

Table 2. Results of average nearest neighbor analysis of heritage buildings in southern China.

Projects	Results
Nearest Neighbor Index R	0.4993
Observed Distance di/m	17,428.3795
Expected Distance de/m	34,906.1134
Z-score	−30.0019
p-value	0.00
Distribution Characteristics	Strongly clustered

), heritage buildings in the southern provinces and cities of China were found to exhibit an average observed distance of 17.4 km, an average expected distance $r_E$ of 34.9 km, a nearest neighbor index R value of 0.4993, and a z value of −30.0019. The p value, which was less than 0.01, indicated a strong spatial clustering distribution characteristic of southern heritage buildings.

This study utilized the kernel density estimation tool of ArcGIS 10.7 to analyze the spatial clustering of heritage buildings across 15 provinces and regions in southern China (Figure 2). The kernel density value can reflect the overall distribution characteristics of heritage buildings; the higher kernel density value indicates a denser distribution of heritage building points. The results of the kernel density analysis revealed that the distribution of heritage buildings is highly uneven, with a concentration in the middle and lower reaches of the Yangtze River plain, followed by the eastern coastal areas and the Sichuan basin. The kernel density likewise varied significantly between the east and west, with a trend of “more in the east and less in the west”. According to the study, the middle and lower plains of the Yangtze River, Fujian, and Sichuan have the highest concentration of heritage buildings.

3.1.2. Characteristics of the Distribution of the Number of Heritage Buildings in the Province

Figure 3 illustrates the distribution of heritage buildings in the 15 southern provinces and cities of China. The data indicate a significant variation in the number of heritage buildings across these regions. Zhejiang, Jiangsu, Anhui, Fujian, and Sichuan have a higher number of heritage buildings distributed in their provinces and cities, while Shanghai, Chongqing, Guangxi, and Hainan have a lower number of heritage buildings distributed.

An imbalance index analysis was conducted on the number of provinces and regions, resulting in an S-value of 0.396, which indicates an uneven distribution of heritage buildings in the southern regions of China. The degree of bending of curve (Figure 4) is of great significance because it can intuitively reflect the degree of equilibrium or imbalance in the distribution of heritage building sites in southern China. The greater the degree of bending, the more unequal the distribution of heritage building points and vice versa. As shown in Figure 4, the Lorenz curve is far from the uniform distribution, indicating a significant arc that represents the uneven distribution of heritage buildings in the region. The provinces of Zhejiang, Sichuan, Jiangsu, Fujian, and Anhui account for over 57% of the total number of heritage buildings, while Chongqing, Hainan, and Shanghai have fewer heritage buildings.

3.2. Spatially Differentiated Features of Heritage Buildings from Different Dynasties

In this study, heritage buildings in southern China were categorized into four time periods based on their construction dates. The first period includes the Spring and Autumn period, the Warring States period, the Qin Dynasty, and the Han Dynasty to the Northern and Southern Dynasties. The second period comprises the Tang–Song dynasties, the third period includes the Yuan–Ming dynasties, and the fourth period consists of the Qing dynasty–Republic of China. Figure 5 presents the number of heritage buildings from each period. The largest number of heritage buildings (410) are distributed from the Yuan–Ming Dynasty. Following that, the period from the Qing Dynasty–Republic of China has the second largest number of heritage buildings, with 377. In southern China, a total of 176 heritage buildings from the Tang Dynasty to the Song Dynasty have been preserved. By contrast, the number of heritage buildings from the Spring and Autumn period to the Northern and Southern Dynasties periods in the southern region is only 18.

A comparison of the elements of different periods in a fixed study area can be made using the average nearest neighbor analysis method, which can determine the average distance of the same period of heritage building sites in southern China and clarify the spatial distribution of heritage buildings. To explore the spatial characteristics of heritage buildings in each of the four periods, average nearest neighbor analysis was employed and the results are recorded in

Table 3. Results of average nearest neighbor analysis of heritage buildings of different periods.

Time	Nearest Neighbor Index R	Observed Distance di/m	Expected Distance de/m	Z-Score	p-Value	Distribution Characteristics
Spring and Autumn Period–Southern and Northern Dynasties	0.8263	125,535.4925	151,928.8986	−1.4100	0.16	Insignificant
Tang–Song Dynasty	0.5858	41,630.1366	71,063.9755	−10.5120	0.00	Strongly clustered
Yuan–Ming Dynasty	0.5869	50,457.2026	29,613.9577	−16.0017	0.00	Strongly clustered
Qing Dynasty–Republic of China	0.5184	28,494.3869	54,962.2124	−17.8877	0.00	Strongly clustered

. The analysis revealed significant differences in the distribution characteristics of buildings in the four periods. Specifically, the Spring and Autumn period and the Southern and Northern Dynasties period did not exhibit significant clustering, with an R-value of 0.8263, a Z-value of −1.4100, and a p-value of 0.16. During the Tang–Song Dynasty, Yuan–Ming Dynasty, and Qing Dynasty–Republic of China periods, heritage buildings were strongly clustered, as indicated by nearest neighbor index R-values of 0.5858, 0.5869, and 0.5184, respectively. Based on the smallest nearest neighbor index R-value, it can be concluded that the spatial agglomeration of the Qing Dynasty–Republic of China period was the most significant, with an observed distance of approximately 28.5 km. On the other hand, the observed distances for the Tang–Song Dynasty and Yuan–Ming Dynasty periods were farther away, measuring about 41.6 and 50.5 km, respectively.

In this study, kernel density estimation was utilized to identify the core areas where heritage buildings were clustered during four distinct periods. The default parameters of ArcGIS 10.7 were used to set the search radius and other parameters. The results, as depicted in Figure 6, indicate a significant spatial heterogeneity in the distribution of heritage buildings during the four periods.

During the Spring and Autumn and Warring States period to the Northern and Southern Dynasties period, heritage buildings were predominantly clustered in the Sichuan basin, forming a high-density grouping in the region (Figure 6a). The heritage buildings in Sichuan were primarily from the Qin and Han dynasties, with Dujiangyan, Binh Duong Fu Junque, and Shen Fu Junque being the most widely distributed. Since the Han Dynasty, Sichuan has been referred to as the “Land of Heaven” because of its exceptional natural conditions. Additionally, Chengdu held the position of political center during the Shu Han Dynasty.

The Tang–Song Dynasty is distinguished by a “double core” of heritage buildings, primarily located in the Jiangsu and Zhejiang regions of the Yangtze River Delta and the eastern coast of Fujian (Figure 6b). The Yangtze River Delta region has a wider distribution and a higher density of heritage buildings, including notable sites such as Lingyin Temple, Linhu Temple, and Ganlu Temple. During this period, the economic center of the country shifted southwards. The Southern Tang Dynasty had its capital in Nanjing, located in Jiangsu Province. In addition, the capital of the Southern Song Dynasty was moved from Kaifeng in the north to Hangzhou.

The heritage buildings from the Yuan Dynasty to the Ming Dynasty period in Anhui and southern Jiangsu, as well as the northwest of Zhejiang Province, form a “double core” pattern (Figure 6c). This suggests that the main development of heritage buildings during this period occurred in the middle and lower reaches of the Yangtze River region. The Sichuan basin also has a great number and density of heritage buildings. Furthermore, heritage buildings from this period are scattered throughout other provinces and cities. The economic recovery of the Yuan Dynasty, coupled with the establishment of the capital in Nanjing, Jiangsu, at the beginning of the Ming dynasty, and the favorable natural conditions of the middle and lower reaches of the Yangtze River plain, were key factors that led to the population growth and economic prosperity of the region.

During the Qing Dynasty-Republic of China period, heritage buildings were distributed in a “multi-core” manner (Figure 6d). The Yangtze River Delta region was the main core area and had the highest density of buildings. Other core areas included the eastern coastal areas of Fujian Province, the Sichuan basin, and the Guizhou–Hunan border, which also had a significant number of heritage buildings.

From a historical perspective, there appears to be a significant gap in the temporal distribution of cultural heritage buildings in southern China. Specifically, there are no cultural heritage buildings from the pre-Qin and Sui dynasties in this region during the historical period. Furthermore, the number and density of cultural heritage buildings in southern China vary greatly depending on the time period being examined.

3.3. Distribution Characteristics of the Type Dimension

In the “Chai Zejun Ancient Architecture Anthology”, heritage buildings in the south are classified based on their functions and appearance characteristics. The classification includes palace building, defensive building, monumental building, garden architecture, sacrificial architecture, water building, residential architecture, religious building, civic architecture, mausoleum building, social architecture, and productive building. The distribution of these different building types is shown in a bar chart (Figure 7). This study revealed that religious architecture was the most prevalent building type in the southern region, followed by residential and ritual architecture. Productive, social, mausoleum, cultural, recreational, and palace buildings are less commonly found. The findings suggest that religious buildings are less susceptible to destruction during dynastic changes and that provinces tend to prioritize a particular type of heritage building when applying for national heritage protection designation. The number and types of heritage buildings vary due to natural, human, socio-economic, and other factors.

Different types of heritage building have unique functions and characteristics (

Table 4. Types of heritage buildings in southern China by dynasty.

	Spring and Autumn Period–Northern and Southern Dynasties	Tang–Song Dynasty	Yuan–Ming Dynasty	Qing Dynasty–Republic of China
Water Building	Dujiangyan	Yuliang Dam	She County Taiping Bridge	Chengyang Yongji Bridge
Mausoleum Building	Binh Duong Fu Junque		Tomb of Taibo	Tomb of Pang Tong
Civic architecture		Huangshan Ancient Road	Dongpo Academy	Yuelu Academy
Residential Architecture	Linga Ancient City	Ancient Buildings of Quanzhou Port	Hongcun Ancient Building	Tung Sang Wai
Social Architecture			Zheng’an County Affairs Main Hall	Jeon Jin Guild Hall
Productive Building		Zhuo Tube Well	Ancient Fiberway	Suzhou Weaving Department
Garden Architecture			Lion Forest Garden	Qiyuan
Defensive Building	Kedu Coach Road	Danba Gu Diao Group	Nanjing City Wall	Xifeng Concentration Camp
Sacrificial Architecture	Huishan Town Ancestral Hall	Quanzhou Confucian Temple	Taiping Mountain House	Wuhou Temple
Religious Building		Lingyin Temple	Hoian Qingshan Palace	Kokuseiji Temple
Monumental Building		Yuan Zhou Tower	Zhangzhou Stone Arch	Taibai Building
Palace Building			Jingjiang Royal Mansion	Golden Hall of Taihe Palace

). Water buildings are constructed on rivers, lakes, and other water bodies, serving as bridges, embankments, canals, and weirs. Examples of water buildings in southern China include Dujiangyan and Yuliang Dam. Mausoleum buildings are designed as a special place for burial and sacrifice, reflecting religious characteristics, filial piety, and Feng Shui concepts. Civic architecture serves cultural and recreational purposes, combining practicality and artistry. Examples include academies and theaters, such as the Dongpo Academy and the Yuelu Academy. Residential architecture is a type of building designed to meet the basic needs of people. It is one of the earliest types of architecture in history. Social architecture, on the other hand, has a specific social function and is typically built by chambers of commerce and merchant groups. These buildings provide spaces for discussion, entertainment, and social interaction, such as meeting houses and post stations. Productive buildings such as salt wells, tea farms, and porcelain kilns are constructed during the production process. Garden architecture is a significant aspect of Chinese architectural art that incorporates the aesthetic qualities of classical Chinese philosophy, literature, and calligraphy. Defensive buildings, sacrificial architecture, and religious buildings are important types of buildings for different purposes. Defensive buildings serve national and urban security purposes, with military defenses such as city walls, towers, and post roads. Sacrificial architecture is a place for various rituals to express reverence and gratitude to heaven and earth or ancestors and generally pursues simplicity, dignity, and solemnity with rich symbolism. Its pattern is generally more meaningful than functional. Religious buildings are important places for people to engage in religious activities, including Buddhist temples, pagodas, grottos, Taoist temples, and Islamic mosques. Temple buildings are mostly built as courtyards, except for cave temples. Monumental buildings are constructed to honor significant individuals and events, featuring ideological, artistic, and lasting elements such as pagodas, monuments, and towers, which hold ornamental and commemorative significance. Palace buildings are grand structures constructed by rulers to solidify their authority, showcase the splendor of their power, and cater to both their spiritual and material pleasures. These buildings typically comprise palaces, government offices, halls, and mansions. Taihe Palace is a prime example of this architectural style.

4. Discussion

This study shows that the distribution of heritage buildings in the southern region is uneven, with varying degrees of temporal and spatial agglomeration. The spatial distribution of heritage buildings in the south is notably uneven, with the eastern coast and Sichuan being the most prominent areas. The temporal distribution is also uneven, with the four temporal phases exhibiting distinct clustering characteristics. Furthermore, the distribution of heritage buildings in the south displays a clear generational gap, with no Pre-Qin period or Sui Dynasty heritage buildings found in the historical period. In terms of building types, religious, residential, and sacrificial architecture are the most prevalent, whereas other types are relatively scarce.

The number, construction time, and type of distribution of heritage building sites in the south vary across different provinces and are mainly influenced by natural, human, and socio-economic factors. Chen Junzi et al. and Han Ying et al. showed that natural resources, topography, and rivers play significant roles in determining the spatial distribution of these sites [43,44]. This finding is consistent with the results of Chen Jinhua et al. on the spatial distribution of cultural heritage in ASEAN countries [45]. The distribution and density of heritage buildings are influenced by both natural resources and topography. Availability of building materials and ease of access are factors that are impacted by the surrounding terrain. Human adaptation and use of nature play a significant role in the development of heritage buildings. Flat terrain is more conducive to the gathering of building materials and populations, making it easier to form and develop a heritage building. The impact of rivers on the distribution of heritage buildings is evident in several ways. First, fertile soil in the alluvial zones of rivers provides ideal conditions for agriculture, which in turn supports settlements. Second, the abundance of water along the rivers facilitates irrigation, enabling people to grow crops even in arid regions. Third, river valleys serve as channels of interaction between settlements, promoting cultural exchange and facilitating production. Finally, Feng Shui thinking often considers rivers as the gathering place of early human life, leading to the concentration of heritage buildings remaining in these areas. These observations are consistent with the findings of Han Zou et al.’s study on the spatial and temporal evolution of the relationship between water systems and historical settlement sites in Hankou, Wuhan, from 1635 to 1949 [46]. The distribution of heritage buildings is highly concentrated in provinces such as Sichuan, Jiangsu, Zhejiang, and Fujian, owing to their abundant resources, flat topography, and numerous rivers, all of which are natural factors that contribute to this phenomenon.

The distribution of heritage buildings is influenced by a variety of factors, including natural environmental factors, historical and cultural factors, and socio-economic factors. In addition to the study by Wu Qing and He Qiuxian on the spatial and temporal distribution characteristics and influencing factors of ancient buildings across the country [47], this conclusion also takes into account population migration factors. The distribution of heritage buildings in China can be attributed to both historical and cultural factors. Sichuan, Zhejiang, and Jiangsu provinces have a higher concentration of heritage building remains due to their significance as former capitals of various dynasties. For example, Chengdu in Sichuan served as the capital of the Shu Han period, Hangzhou in Zhejiang was the capital of the Southern Song Dynasty, and Nanjing in Jiangsu was the capital of the Ming, Jin, and Southern Dynasties. Nanjing is also famously known as “The ancient capital of the Six Dynasties”. The second factor contributing to the development of heritage architecture in southern China was the migration of the Chinese population. Throughout Chinese history, there have been three major southward migrations, primarily toward the middle and lower regions of the Yangtze River. As a result of these migrations, the southern region saw an influx of people, leading to advancements in agricultural and handicraft technologies, increased grain production, and growth in commercial trade. The number of towns and cities in the southern region surpassed those in the north as well. This migration played a fundamental role in shaping the spatial and temporal distribution pattern of southern China’s development. In addition to historical and cultural factors, socio-economic factors also play a crucial role in the conservation and development of heritage buildings. The level of economic development serves as the foundation for the preservation of these structures and financial support is essential for their continued protection and development. However, the uneven distribution of socio-economic development across different regions can lead to significant disparities in the abundance of heritage building remains and the intensity of their preservation and development efforts between provinces.

While this study provides valuable insights, it is important to note its limitations. First, the research methodology employed was homogeneous because the spatial and temporal distribution of heritage buildings was only analyzed using the nuclear density analysis method. To increase the diversity of research methods, future studies could incorporate additional analytical techniques. Second, the temporal classification of some heritage buildings in the National Key Cultural Relics Protection Units was unclear due to the lack of a clear date of completion. Therefore, this study used the date of the beginning of the heritage buildings as a basis for classifying their time period. In future studies, the date of construction of heritage buildings should be used as a basis for classification and authoritative documents should be consulted to improve the precision of classification. Finally, the study solely focused on analyzing heritage buildings that have been listed as cultural relics. However, there exist numerous heritage buildings that are not listed as cultural relics but still hold significant research value. In the future, more information on unlisted heritage buildings will be collected to conduct in-depth studies on these buildings. These efforts will further enhance our understanding of heritage buildings.

5. Conclusions

This study aimed to analyze the differences in the spatial distribution characteristics of cultural relics buildings across different periods and types in southern China and to examine their spatial clustering and distribution characteristics. Additionally, it sought to explore the factors contributing to the differences in spatial distribution characteristics and the variety of types.

This study examined 981 national-level cultural relic buildings in southern China that have been recognized by the State Council since the founding of New China. The research categorized these cultural relic buildings into four stages based on their construction period: Spring and Autumn Period–Southern and Northern Dynasties, Tang–Song Dynasty, Yuan–Ming Dynasty, and Qing Dynasty–Republic of China. Additionally, this study classified heritage buildings into 12 different types based on their functions and characteristics. The spatial distribution and distribution characteristics of buildings from different dynasties and types were analyzed using methods such as average nearest neighbor analysis, unbalance index, and kernel density estimation. It investigated the relationship between the distribution of cultural relics and buildings and the various natural, humanistic, and socio-economic factors. This study revealed several key findings. First, the spatial distribution of cultural relics buildings in southern China exhibited a general pattern of unevenness and agglomeration. Specifically, cultural relics buildings were predominantly concentrated on the eastern coast and in Sichuan Province. The spatial distribution of cultural relics and buildings also varied across different dynastic zones. Cultural relics and buildings in Sichuan Province were found to be primarily from the Spring and Autumn Period–Southern and Northern Dynasties period. In contrast, the Tang–Song Dynasty witnessed two aggregation zones, mainly located in the middle and lower reaches of the Yangtze River and Fujian Province. The Yuan–Ming Dynasty heritage buildings were mainly distributed in the middle and lower plains of the Yangtze River and Sichuan. Lastly, the heritage buildings from the Qing Dynasty to the Republic of China era were distributed across multiple cores, primarily in the Yangtze River’s middle and lower plains. The number of heritage buildings varied greatly, with religious buildings being the most common type. When analyzing the distribution and number of cultural relic buildings, we found that natural, human, and socio-economic factors influenced their differences.

Previous research has predominantly focused on individual building research at a micro scale, often neglecting the broader spatial distribution of heritage buildings. This study aimed to address this gap by analyzing the spatial relationship between heritage buildings and the various types of differences at a macro scale. This study also considered the influence of population migration on the distribution of heritage buildings, a factor that has often been overlooked in previous studies. This study has practical significance. Analysis of the spatial distribution and types of heritage buildings allowed this study to conclude that an imbalance exists in the spatial distribution and types of heritage buildings. This conclusion provides guidance for the management department in declaring, protecting, and developing heritage buildings. It prompts the relevant departments to allocate human and financial resources more reasonably.