Spatio-Temporal Distribution Evolution Characteristics and Geographical Influencing Factors of Cultural Heritage Sites in Xinjiang, China

Abstract

Cultural Heritage Sites (CHS) serve as tangible evidence of regional human–environment interactions and spatial representation of historical memory. The research developed a Xinjiang CHS database and integrated geographic information technology and historical geography research methods to examine the spatio-temporal distribution evolution characteristics and geographic influencing factors in the arid region. It utilized the nearest neighbor index, kernel density estimation, the center of gravity model, and standard deviation ellipse to explore the spatio-temporal evolution law. Furthermore, it employed spatial overlay and qualitative text to analyze the geographical influence mechanism of the CHS. The results showed the following: (1) The CHS spatial distribution showed a pattern of “multicore agglomeration-linear extension”, concentrated in 13 key cities and four major areas that extended along the Silk Road routes. (2) The CHS diachronic development fluctuated in a pattern of “three peaks and three valleys”. The spatial center of gravity has shifted from southern Xinjiang to northern Xinjiang, manifesting a concentrated-diffused characteristic along the northeast–southwest axis. (3) The spatial selection followed the rules of “preferring lower terrain” and “proximity to water”. The elevation distribution of CHS has shifted from mid-high elevations to low elevations. The proportion of CHS on low-slope terrain increased from 78.6% in the Pre–Qin period to 93.02% in Modern History. 93.02% of CHS in Modern History were distributed within the 10 km buffer zone of rivers. (4) Climate aridity and human activities formed a dynamic influence mechanism; natural factors constructed the base pattern of CHS distribution, and human activities drove the dynamic adjustment. The findings revealed the historical trajectory and driving logic of the evolution of CHS in Xinjiang and provided a scientific basis for cultural heritage protection and ecological governance. This study had limitations in terms of the limited research scope and the lack of comprehensive quantitative analysis of influencing factors.

1. Introduction

As the product of the interaction between regional culture and the natural environment, CHS are the material carriers of human historical activities and spatial representation of cultural memories. They not only carry information about human production and daily life in specific historical periods but also serve as important means for understanding the dynamic evolution of the human–environment relationship [1]. UNESCO stresses that protecting cultural sites is not only the key to preserving human memory and identity, but also an important means to promote sustainable development, enhance cultural diversity, and promote social inclusion [2]. Through the CHS systematic analysis from historical periods, we can uncover the methods of production and daily life of humans in different historical stages, the evolution of social structures, and the dynamic changes in the human–environment relationship. This provides historical experience and cultural insights for the sustainable development of contemporary society.

Previous studies on CHS have mostly focused on fields such as cultural studies, history, and archeology. In recent years, with the introduction of the geographical perspective, especially the application of remote sensing and Geographic Information System (GIS) technologies, research on cultural sites has gradually evolved from solely focusing on historical textual evidence to incorporating geographical spatial pattern analysis [3]. In terms of research content, scholars are committed to exploring the spatial patterns and spatio-temporal evolution characteristics of cultural heritage and analyzing their influencing factors from multiple perspectives such as nature, culture, industry, and urban areas. Thus, they can systematically reveal the spatial distribution rules [4], development models [5], cultural regionalization [6], driving factors [7], etc., of cultural heritage. In terms of research methods, the introduction of technologies such as satellite image interpretation [8], spatial statistical analysis, trend surface analysis [9], and social network analysis [10] has provided strong support for the quantitative research of CHS. The research objects cover a wide range, from cultural relic protection units [11] and specific archeological sites [12] at the micro-level, to famous historical and cultural towns, villages [13], and blocks [14] at the meso-level, as well as historical central zones [15] and famous historical and cultural cities [16] at the macro-level. The research areas are mostly concentrated in different types of regions such as administrative units [17] and important natural river basins [18].

However, the existing research still has certain limitations. Firstly, there is a lack of systematic induction of CHS spatial structure evolution in different periods. Most studies focus on the description of static spatial pattern, failing to capture the dynamic evolutionary processes of CHS as living heritage. This static-oriented perspective not only overlooks the spatio-temporal embeddedness of historical contexts—the close link between the spatial morphological evolution of CHS and specific historical circumstances—but also lacks empirical support from long-term spatio-temporal data for modern conservation efforts. Furthermore, the spatio-temporal dynamic analysis of CHS provides a unique perspective for examining the human–environment relationship in historical research, but few studies have systematically employed this to interpret historical development trajectories and human activities. Additionally, the analysis of influencing factors frequently neglects comprehensive historical–geographical considerations, particularly the integration of critical variables like paleoclimatic fluctuations and shifts in political centers. Regionally, arid areas remain markedly understudied despite their distinctive climatic and geographical conditions that create unique spatio-temporal heterogeneity in CHS distribution and human–environment interactions. Significantly, the co-existence of ecological fragility and cultural succession sensitivity in arid regions makes them particularly valuable for examining human–environment relationship evolution in extreme conditions.

As the core distribution area of CHS on the Silk Road and a typical arid region, Xinjiang’s CHS spatio-temporal evolution laws serve as a crucial entry point for revealing the evolution of the human–environment relationship in arid regions. Taking Xinjiang as a typical case, this study utilizes multi-source historical and geographical data and GIS spatial analysis to achieve three objectives: (1) to reveal the spatio-temporal distribution evolution characteristics of CHS in historical periods; (2) to examine how natural geographical and historical-human factors influence CHS spatio-temporal distribution dynamics; (3) to extract and present crucial evidence for regional historical development insights from CHS spatio-temporal distribution analysis and propose specific proposals for regional CHS sustainable development.

Motivated by the above-mentioned aims, this study constructs a database that includes attributes such as the era, type, and scale of the sites, and comprehensively uses methods like the nearest neighbor index, kernel density estimation, the center of gravity model, and standard deviation ellipse to quantitatively analyze the spatio-temporal evolution characteristics of CHS. Through historical literature verification and spatial overlay analysis, it reveals the interaction mechanism of natural–human factors. By integrating the dual perspectives of “chronological reconstruction” in historical geography and “spatial analysis” in geographic information science, this study not only overcomes the dilemma of the separation between “diachronicity” and “synchronicity” in traditional heritage site research but also provides a new analytical paradigm for the study of the evolution of human–land systems in arid regions. Moreover, it offers scientific evidence for the construction of the Silk Road cultural heritage corridor, the protective development of heritage sites in ecologically vulnerable areas, and decision-making regarding the appropriate utilization of cultural resources in territorial spatial planning.

2. Materials and Methods

2.1. Study Area

Xinjiang Uygur Autonomous Region is located in the northwest of China, covering an area of 1,664,900 square kilometers, which is the largest provincial administrative region in China (Figure 1) [19]. It has a geographical layout of “three mountains and two basins”. The Altai Mountains, Tianshan Mountains, and Kunlun Mountains encircle the Junggar Basin and the Tarim Basin. The Tianshan Mountains in the middle divide Xinjiang into Southern Xinjiang and Northern Xinjiang. The complex topographical structure endows Xinjiang with remarkable diversity in terms of climate, landforms, and ecology. It features a typical temperate continental arid climate, characterized by large annual and daily temperature variations [20]. Geographical landscapes such as alpine glaciers, vast gobi deserts, and wetland oases coexist, each possessing its unique characteristics. Xinjiang was historically known as “Xiyu” (the Western Regions). In history, it was an important passage on the ancient Silk Road and a necessary route for the New Eurasian Land Bridge, holding a significant strategic position [19]. Acting as a nexus linking ancient China to the world, it has gathered a diverse array of civilizations. Religions such as Buddhism, Islam, and Christianity were spread here, leaving behind rich historical relics like the Jiaohe Ancient City, Gaochang Ancient City, and Kizil Caves, which demonstrate the integration and coexistence of diverse religious cultures (Figure 2). Meanwhile, Xinjiang is also the birthplace of ancient civilizations of Xiyu, such as Loulan, Qiuci, and Yutian. These city-states played significant roles along the Silk Road, leaving behind a wealth of cultural relics and artistic treasures [21]. As a region inhabited by multiple ethnic groups, including the Han, Uyghur, Kazakh, and Mongolian peoples, it has formed a unique ethnic cultural ecosystem [22]. The coupling of the natural environment, historical culture, and geographical location has endowed Xinjiang’s CHS with rich connotations and complex cultural changes, making it a focal area of interest in historical geography.

2.2. Data Sources

China implements a tiered management system for cultural relics protection units through a three-level framework comprising national, provincial (autonomous), and municipal (county) levels [23]. Due to the implementation of unified evaluation criteria for national-level and provincial-level cultural relics protection units, their spatial distribution characteristics can be regarded as an effective representation of the spatio-temporal pattern of cultural sites within a province, holding significant research representativeness [24]. The CHS data are sourced from the lists of national key cultural relic protection units announced by the State Council in eight batches and the lists of autonomous-region-level cultural relics protection units announced by the Xinjiang Uygur Autonomous Region in eight batches (https://ncha.gjzwfw.gov.cn/, https://www.xinjiang.gov.cn/). These lists were determined after multiple rounds of argumentation and evaluation by expert review teams and expert review committees organized by the State Council and the people’s government of the autonomous region. They are currently the only directly accessible, reliable, and officially announced data sources for cultural relics protection units. Among them, there are 134 national key cultural relics protection units (NCHS) and 573 cultural relics protection units at autonomous-region-level (PCHS) in the research area. By referring to the official websites of the State Council, the autonomous region, and local governments at all levels, detailed attribute information about the cultural relics’ protection units is obtained, including their names, dates, types, administrative divisions, geographical coordinates, and addresses. According to the research requirements, a few CHS with uncertain types and dates are excluded, and 698 CHS are retained. Based on the chronological division system, and in combination with historical studies, the political, economic, and cultural characteristics of different periods in Xinjiang, as well as existing research findings [1,25], the periods in which the CHS are located are divided into eight periods: the Prehistory (Paleolithic Age, Neolithic Age), Pre–Qin (including the Bronze Age and Iron Age), Qin–Han, Wei–Jin (including the Three Kingdoms, the Two Jins, and the Northern and Southern Dynasties), Sui–Tang (including the Five Dynasties and Ten Kingdoms Period), Song–Yuan, Ming–Qing, and Modern History. Given the continuity across different historical periods of some CHS, they are counted separately based on their respective historical periods.

The auxiliary data encompass Silk Road route data and influencing factor data. The Silk Road route data are obtained from the SHP file of the Silk Road thematic data layer on Tianditu (China’s National Geographic Information Public Service Platform). Influencing factor data are categorized into natural and human factors. Within established archeological research paradigms [26], the combined analysis of natural factors (e.g., elevation, climate, rivers, vegetation) and human factors provides a fundamental analytical framework for investigating the spatial distribution and formation processes of CHS. Based on a review of existing literature and consideration of Xinjiang’s unique characteristics, this study selects natural factors such as terrain [6,7], rivers [6,7], and climate [1,22], as well as human factors like politics [10], economy [10,11], and war [27], to demonstrate their driving effects on CHS distribution. Regarding the data used, (1) the terrain data, which include elevation and slope information, are extracted from Digital Elevation Model (DEM) data. The DEM data are derived from the Resources and Environmental Science Data Center (RESDC) of Chinese Academy of Sciences, with a spatial resolution of 30 m by 30 m. (2) The river system data are derived from the level 1–8 river system line data extracted from OSM (OpenStreetMap) data. (3) The data on climate and human geographical factors are sourced from the textual materials, including Xinjiang local historical documents and texts on geological environment analysis.

2.3. Study Methods

First, based on the relevant attribute information of 698 CHS obtained from the official websites, the database for this study is constructed. For some autonomous-region-level cultural relic protection units with unclear latitude and longitude information, their corresponding geographical coordinates (latitude and longitude) can be collected through the Baidu Coordinate Selection System according to the addresses published on the official websites of local governments. Second, based on the “Standard Map of the Ministry of Natural Resources of the People’s Republic of China with the review number GS (2023) 2767”, the article uses ArcGIS 10.8 to construct a regional map of Xinjiang’s CHS (see Figure 1). It also introduces methods such as the nearest neighbor index, kernel density estimation, center of gravity model, and standard deviational ellipse to identify and analyze the overall distribution characteristics of Xinjiang’s CHS as well as the spatio-temporal evolution features of each period. Finally, with the help of spatial overlay and qualitative analysis methods, historical geographical factors related to the development of CHS, including both natural and human aspects, are identified (Figure 3). The specific analysis methods are as follows:

2.3.1. Analysis Methods of Spatio-Temporal Distribution Evolution Characteristics

Given that CHS data are point-based, the article employs four methods for point analysis to reveal the spatio-temporal distribution evolution characteristics of CHS. Specifically, the nearest neighbor index is employed to assess the overall spatial distribution pattern of CHS. Kernel density estimation is further utilized to identify high-density clusters with concentrated heritage sites. The center of gravity model is applied to analyze the distribution center and its historical displacement pattern of CHS. The standard deviation ellipse method is used to quantify the orientation and spatial extent of CHS distribution. These four methods collectively establish a methodological framework from overall distribution pattern recognition to spatio-temporal detail analysis.

(1)

Nearest neighbor index

Through the comparison between the actual average distance and the theoretical nearest neighbor average distance, the method identifies the spatial clustering or dispersion status of the point data [28]. If the index satisfies 0 < R < 1, the point features tend to show a clustered distribution; if R > 1, the point features tend to present a dispersed distribution; if R = 1, the point features tend to follow a random distribution.

(2)

Kernel density estimation

Using kernel density estimation can intuitively display the spatial distribution pattern of CHS. As a non-parametric estimation method, it can reflect the distribution of discrete measurement values in a continuous area by calculating the unit density of point and line features within a specified neighborhood range [29].

$$f\left(x\right)={\displaystyle \frac{1}{n{h}^2}}{\sum }_{i=1}^n{p}_{i}K({\displaystyle \frac{dist(\left(x,y\right),\left(x_i,y_i\right))}{h}}).$$

(1)

f(x) represents the kernel density value at a certain point x in the study area; the function K() is the spatial weight function, which is generally a distance decay function; $p_i$ is the given weight field, n is the number of feature points whose distance to point x is less than or equal to h, and h is the search radius.

(3)

Center of gravity model

The center of gravity model clarifies the distribution changes in a certain attribute value in the study area by calculating the coordinates of the center of gravity and depicting the migration path of the center of gravity [30]. To explore the changing trend of the center of gravity in different eras, the study also calculates the moving distance of the center of gravity between the coordinates.

$$\overline{X}={\displaystyle \frac{1}{N}}{\sum }_{i=1}^n{x}_{i }, \overline{Y}={\displaystyle \frac{1}{N}}{\sum }_{i=1}^n{y}_i,$$

(2)

$$D=C\times \sqrt{{\left(\overline{x_{t+1}}-\overline{x_t}\right)}^2+{\left(\overline{y_{t+1}}-\overline{y_t}\right)}^2}.$$

(3)

$\overline{X}$ and $\overline{Y}$ are the longitude and latitude of the center of gravity of the CHS in the study area. $x_{i }$ and $y_i$ respectively represent the central coordinates of each spatial unit in the study area; D represents the planar moving distance between the center of gravity coordinates in the t + 1 period and those in the t period, and C is constant with a value of 111.111 km/ (°).

(4)

Standard deviation ellipse

Standard deviation ellipse reflects the spatial distribution range, trend, and discrete characteristics of CHS, such as the long axis, short axis, rotation angle, area, and other basic parameters [31]. The long and short axes reveal the characteristics of the changes in the primary and secondary directions. The rotation angle is measured clockwise from the due north direction, which clearly indicates the main direction of the data distribution. The area is used to describe the size and shape of the ellipse, helping to quantify the extent of the data distribution.

$$\tan \theta ={\displaystyle \frac{\left(\sum _{i=1}^n{\widetilde{x_i}}^2-\sum _{i=1}^n{\widetilde{y_i}}^2\right)+\sqrt{{\left(\sum _{i=1}^n{\widetilde{x_i}}^2-\sum _{i=1}^n{\widetilde{y_i}}^2\right)}^2+4\sum _{i=1}^n{\widetilde{x_i}}^2{\widetilde{y_i}}^2}}{2\sum _{i=1}^n\widetilde{x_i}\widetilde{y_i}}}.$$

(4)

where θ is the angle of the ellipse; and $\widetilde{x_i}$,$\widetilde{y_i}$ respectively represent the coordinate deviations from the central coordinates of each spatial unit to the barycentric coordinates.

2.3.2. Analysis Methods of Geographical Factors

The analysis methods of natural and human factors are as follows: (1) Spatial overlay analysis. The method is performed on the selected elevation and slope data, river information, and the distribution map of CHS. Through the overlay analysis, the specific elevation and slope values of each point are obtained, and the number of points within the river buffer zone is counted. (2) Qualitative analysis of historical geography. The article combines materials such as Xinjiang local historical documents, and texts on geological environment analysis to trace the evolution process of the local natural and cultural history. In this way, it sorts out the natural and human geographical factors that influence the evolution of CHS.

3. Results

3.1. Spatio-Temporal Distribution Evolution Characteristics

3.1.1. Overall Distribution Characteristics

The nearest neighbor index (R) of the CHS distribution in Xinjiang is 0.386, and the Z value is −31.22. It passes the 1% significance test, indicating that CHS spatial distribution in Xinjiang shows a significant clustered distribution pattern. From north to south, 13 key cities with concentrated CHS have emerged (Figure 4), namely Altay (a), Qinghe (b), Jimunai (c), Zhaosu (d), Shihezi (e), Gaochang (f), Hami (g), Turpan (h), Korla (i), Kuqa (j), Kashgar (k), Hotan (l), and Qiemo (m). Based on the location, historical evolution, and the Silk Road branches to which they belong, the sites can be further categorized into four major areas with concentrated heritage sites: the Altai Mountains region, the Northern Route of the Silk Road, the Middle Route of the Silk Road, and the Southern Route of the Silk Road. ① The Altai Mountains region. Located in the hinterland of Altai Mountains, it includes Altay, Qinghe, and Jimunai. There is a total of 77 CHS in this area, which has the fewest CHS in Xinjiang. The sites are mainly dated back to the Pre–Qin period, with ancient tombs accounting for 50.64%. The terrain in this area is mostly alluvial platforms, with the surface covered by gravel accumulation of gobi, and sparse vegetation. This environment is conducive to the preservation and discovery of tombs [32]. ② The Northern Route of the Silk Road. It includes Zhaosu, Shihezi, Gaochang, and Hami. There are 231 CHS in total, accounting for 33.09% of the total number of sites in the study area. The types of sites are mainly ancient ruins, and most of them date back to the Pre–Qin and Ming–Qing period. ③ The Middle Route of the Silk Road. It includes Turpan, Korla, and Kuqa. There are 296 CHS in total, accounting for 42.41% of the total number of sites in the study area. This area has the largest number of CHS in Xinjiang and the highest degree of agglomeration, with two obvious high-density agglomeration areas, namely the Turpan Basin and the oasis area on the northern edge of the Tarim Basin. ④ The Southern Route of the Silk Road. It includes Kashgar, Hotan, and Qiemo. There are 94 CHS in total. The distribution of CHS is closely related to that of piedmont oases. The sites are distributed in a concentrated point-like form in the areas with dense oasis cities on the southern edge of the Tarim Basin. Overall, the ICH distribution shows a multi-core pattern with 13 key cities and four concentrated distribution areas, and they mainly extend along the routes of the ancient Silk Road routes.

3.1.2. Spatio-Temporal Distribution Characteristics of CHS in Historical Periods

(1)

Temporal Distribution Characteristics

The number distribution of CHS varies greatly across different historical periods (Figure 5), showing a wave-like pattern with “three peaks and three valleys”. The first upward trend spans from Prehistory to the Qin–Han periods. Prehistory had the longest time span among the eight historical periods in Xinjiang, yet it had the fewest CHS. During the Pre–Qin period, the number of CHS gradually increased. There were a relatively large number of ancient tombs, accounting for 62.7% of the total sites in this period, which indicates that humans drove the progress of human history through a settled lifestyle. The number of CHS reached the first peak during the Qin–Han period, with a total of 159 sites. Among them, the number of types of ancient ruins increased significantly (Figure 6). The second peak period was during the Sui and Tang dynasties. During this time, the number of CHS in Xinjiang reached the highest level in its historical period, totaling 248 sites, and the number of types of ancient ruins also hit the peak, reaching 190. The third peak period was in the Ming–Qing period, with 150 sites. In this period, the number of ancient buildings increased significantly, and among them, the Karez irrigation systems accounted for the largest proportion. The three peak periods were the three crucial times when Xiyu was unified. During these periods, through military conquests, political administration, and economic and cultural exchanges, Xiyu was incorporated into the historical territory of China, resulting in obvious peak periods in terms of the quantity and types of CHS. Meanwhile, population growth and migration brought about different building techniques and demands, leading to a significant increase in the types of ancient ruins and buildings. The three decline periods occurred in the Wei–Jin, Song–Yuan, and Modern History periods, when there was social unrest, and the Central Plains governments had difficulty achieving effective unification. The numbers of CHS in these three periods were 104, 70, and 86, respectively.

(2)

Spatial distribution characteristics

In terms of the distribution of the center of gravity, the overall center of gravity of CHS has undergone an evolutionary process from the southwest to the northeast (Figure 7). From Prehistory to the Ming–Qing period, the center of gravity generally showed a trend of shifting towards the southwest. From the Ming–Qing to the Modern History period, this trend reversed, and the development center of gravity began to shift towards the northeast. When looking at each specific period, we find the following (Figure 8): ① Prehistory period. The overall CHS were relatively scattered. The center of gravity of CHS was located within the present-day Hejing, Bayingolin Mongol Autonomous Prefecture, at the southern foot of the Tianshan Mountains. ② Pre–Qin period. The center of gravity shifted 68 km northwest to the present-day Shawan in Tacheng Prefecture, at the northern foot of the Tianshan Mountains. The sites were mainly distributed in northern Xinjiang and were obviously concentrated in the northern route area of the Silk Road. ③ Qin–Han period. The center of gravity shifted 122.2 km southwest and returned to the present-day Hejing. The number of sites in the middle and southern route areas of the Silk Road increased significantly. The reclamation in southern Xinjiang and the implementation of the strategy of “emphasizing the south over the north” made southern Xinjiang prominent as the political and economic center. ④ Wei–Jin period. The center of gravity shifted southwestward again by 124.9 km to the present-day Luntai. The cultural sites were mainly concentrated in the middle route area of the Silk Road. ⑤ Sui–Tang period. The center of gravity shifted northeastward by 53.5 km but still remained within Luntai. A total of 85.9% of the sites were concentrated in the middle and northern route areas of the Silk Road, showing an overall northward trend. However, this northward shift was still an expansion within the scope of southern Xinjiang, and the status of southern Xinjiang as the governing center remained unchanged. ⑥ Song–Yuan period. The center of gravity moved 89.2 km southwestward to present-day Kuqa in Aksu, reaching the most south-westerly position among the centers of gravity in all periods. ⑦ Ming–Qing period. The center of gravity moved 124.5 km northeastward and returned to the territory of Hejing. ⑧ Modern History period. The center of gravity continued to move 176.1 km northeastward to present-day Hutubi County in Changji of northern Xinjiang.

Before the Qin–Han period, due to the great mobility of early human activities, the distribution center of CHS was relatively unstable [33]. However, from the Qin–Han period to the Song–Yuan period, the center of gravity of CHS gradually became fixed in southern Xinjiang. As described in existing historical research [34], this is mainly because southern Xinjiang had relatively stable oasis agriculture, which could support large-scale human settlements and the development of civilization. At the same time, the prosperity of the Silk Road made southern Xinjiang an important node for trade and cultural exchanges between the East and the West. Numerous cities emerged here, and many cultural sites such as settlements and religious buildings were created and preserved. Therefore, during this period, the center of gravity of the sites was mainly in southern Xinjiang. From the Qing to Modern History periods, as research has pointed out, there was an emphasis on the development of northern Xinjiang [35]. Large-scale immigration and reclamation activities were carried out in northern Xinjiang, which greatly promoted the comprehensive development of northern Xinjiang. Overall, the development process of the center of gravity of CHS distribution is relatively consistent with the evolution direction of the comprehensive center of gravity in politics, economy, etc., in the historical development of this region.

Table 1. The standard deviational ellipse parameters of CHS spatial distribution in Xinjiang in different historical periods.

	Semimajor Axis (km)	Semiminor Axis (km)	Rotation Angle (°)	Area (km2)
Prehistory	9.53	3.73	69.27	111.77
Pre–Qin	7.16	3.27	84.49	73.59
Qin–Han	6.21	3.56	72.26	69.53
Wei–Jin	5.98	3.07	68.51	57.66
Sui–Tang	6.4	2.22	74.7	44.67
Song–Yuan	7.53	2.5	69.61	59.02
Ming–Qing	7.82	2.78	76.29	68.32
Modern History	6.53	3.07	75.2	63.03

shows that the length of the semimajor axis of the standard deviation ellipse reflects the CHS distribution pattern in Xinjiang in the east–west direction. The length of the semimajor axis was 9.53 km in the Prehistory period, decreased to 5.98 km in the Wei–Jin period, increased again to 7.82 km in the Ming–Qing period, and further decreased to 6.53 km in the Modern History period. This shows a fluctuating evolutionary trend of concentration and expansion. The length of the semi-minor axis reflects the distribution characteristics of the sites in the north–south direction. It decreased from 3.73 km in the Prehistory period to 2.22 km in the Sui–Tang period, and then increased to 3.07 km in Modern History, showing a state of first concentration and then dispersion in the north–south direction. The difference between the major and minor semi-axes decreased from 5.8 km in the Prehistory period to 2.65 km in the Sui–Tang, then increased to 5.04 km in the Ming–Qing period, and finally decreased to 3.46 km in Modern History, showing a centripetal–centrifugal trend. This fluctuating trend causes the rotation angle to change irregularly and slightly, presenting an overall “northeast–southwest” spatial distribution pattern (Figure 7a). The ellipse area has shown a “decrease–increase–decrease” change. It decreased from 111.77 km² in the Prehistory period to 44.67 km² in the Sui–Tang, then increased to 68.32 km² in the Ming–Qing period and decreased again to 63.03 km² in Modern History, showing a convergence–expansion trend. In general, the CHS in Xinjiang across different periods generally exhibits an obvious pattern of concentration–expansion in both primary and secondary trends as well as overall spatial distribution.

3.2. Geographical Influencing Factors

3.2.1. Natural Geographical Factors

(1)

Terrain

The terrain of Xinjiang has not changed much since the Prehistory period [36]. This study takes the current terrain as a reference and considers the relationship between the spatial distribution of CHS in different periods and elevation as well as slope. Specifically, the terrain to some extent determines and restricts the extension of CHS in this region. Based on the research findings of Wang [1], Zhang [36], and Zhu [37], and in combination with the local topographical features of Xinjiang, on the basis of reclassifying in the ArcGIS software, the elevation values (unit: m) in Xinjiang are divided into nine categories: [−233, 500), [500, 800), [800–1000), [1000–1200), [1200–1600), [1600–2000), [2000–2400), [2400–2800), [2800,∞). Among them, the interval [−233, 500) is classified as the first level, [500, 800) is classified as the second level, and so on. The interval of 2800 m or above is classified as the ninth level. The slope values (unit: °) in Xinjiang are divided into eight categories: [0, 2), [2, 5), [5, 8), [8, 11), [11, 15), [15, 20), [20, 25), and [25, ∞). Among them, the interval [0, 2) is the first level, [2, 5) is the second level, and so on. A slope of 25° or above is the eighth level (Figure 9a and Figure 10a). Based on the classification criteria of elevation and slope, the proportions of CHS at different elevations and slopes in each historical period are statistically calculated (Figure 9b and Figure 10b).

In the Prehistory period, due to the limitations of productivity, humans showed a significant tendency towards natural resources. The CHS distribution was closely associated with favorable terrains such as low-elevation and gentle slopes [38]. Throughout the period from the Pre−Qin to Modern History, the scope of human activities gradually expanded. The CHS distribution showed a tendency to shift from high-elevation mountainous and hilly areas to low-elevation plains, and from steep slopes to gentle slopes. The number of CHS decreased significantly with the increase in elevation and slope. Specifically, in the Pre–Qin period, the sites were mainly distributed at elevation level 5; in the Qin–Han and Wei–Jin periods, the sites were concentrated at elevation levels 3–5; in the Sui–Tang period, the sites were mainly at elevation level 3; in the Song–Yuan period, the sites were concentrated at elevation level 5; while from the Ming–Qing to Modern History, the sites were mainly distributed at elevation level 2. The proportion of the number of sites at elevation levels 1–3 increased significantly from 25.4% in the Pre–Qin period to 66.3% in Modern History. In terms of slope distribution, CHS were mainly concentrated on slope levels 1–2, and the proportion increased from 78.6% in the Pre–Qin period to 93.02% in Modern History.

(2)

Rivers

Water resources play a crucial and decisive guiding role in the formation and development of human settlements [39]. Xinjiang has a complex river system with more than 570 rivers. Most of them are inland rivers, while only a few are external rivers. The water sources of these rivers mainly come from precipitation, snow cover, and glacial meltwater in mountain ranges such as the Tianshan Mountains. The article selects rivers at levels 1–8 in Xinjiang as the main objects of analysis (Figure 11a). By using ArcGIS software, it constructs buffer zones around these rivers at intervals of 1 km, 2 km, 3 km, 5 km, 8 km, 10 km, 13 km, 15 km, 18 km, and 20 km [6], and then calculates the number of CHS in different buffer zones of the rivers (Figure 11b).

Within the 2 km buffer zone from the river, the growth rate of all CHS reaches its peak at 60.53%. As the distance from the river increases, the number of CHS in the buffer zone shows a slow upward trend at first, but the increasing trend flattens out significantly when the distance extends beyond 10 km from the river. There are 613 CHS within the 10 km area from the river, accounting for 87.82% of the total. From the perspective of different historical periods, CHS exhibit a relatively high distribution density within the 10 km range from the river (

Table 2. Statistics on the number of CHS at different distances in different historical periods.

	Prehistory	Pre–Qin	Qin–Han	Wei–Jin	Sui–Tang	Song–Yuan	Ming–Qing	Modern History
1 km	9	44	46	24	67	24	59	33
5 km	17	86	107	69	175	55	118	74
10 km	21	103	128	80	208	64	139	80
15 km	21	113	141	89	231	66	144	82
20 km	21	120	150	97	239	67	148	86

). When the distance from the river exceeds 10 km, the growth rate of the number of CHS slows down notably. From the Pre–Qin period to Modern History, the proportions of CHS within the 10 km ranged from the river are 81.75%, 80.50%, 76.92%, 83.87%, 91.43%, 92.67%, and 93.02%, respectively. This changing trend indicates that the impact of rivers on human activities features a significant spatial attenuation characteristic. It should be specifically noted that given existing research proving the occurrence of significant spatial changes in rivers during historical periods [40] and the lack of accurate historical river data, this study analyzes the distribution of CHS based on current river data. Although this method may not fully restore the specific spatial relationship between historical rivers and CHS, the high-proportion distribution of CHS in different periods can still reveal the influence pattern of rivers on human activities. In addition, the fact that the proportion of CHS within a 10 km range from the river is as high as 93.02% in the relatively recent Modern History period further confirms that they generally tend to cluster in areas close to water sources.

(3)

Climate

Based on existing research, the analysis of multiple proxy indicators such as geological profiles, lake sediments, pollen records, and river flow changes in various regions of Xinjiang has revealed the climatic characteristics of different historical periods. The climate environment in Xinjiang has undergone a sequence of changes from cold–wet to warm–dry, then to cold–wet, followed by relatively cold, relatively wet, hot–dry, relatively cool, slightly dry, and finally to temperate–dry [41]. This evolution exhibits significant stage-like and fluctuating characteristics. The relationship between ancient climatic conditions and CHS can be further analyzed in light of these findings.

① Prehistory period. Based on the pollen records from the Tekel Mohur Desert Kekedala Section (TKP) [42] and the wetland section in Caotanhu Village, Shihezi City, Xinjiang [43], it has been discovered that the climate during this period exhibited distinct dry–wet variations. The overall climatic conditions were suitable for human survival and activities, which facilitated the emergence of early agriculture and animal husbandry [44]. Influenced by these favorable climatic conditions, CHS formed as humans gradually settled and were distributed in the Altai Mountains, Turpan Basin, and the Piedmont alluvial fan areas at the northern foot of the Kunlun Mountains.

② Pre–Qin period. The comprehensive analysis of lake level fluctuations and surrounding environmental changes in Sichang Lake, Dongdaohaizi Lake, and Aibi Lake reveals that the climate during this period was primarily characterized by a combination of cold–wet and warm–dry patterns [45,46]. Under this climatic regime, the cold–wet phases provided relatively abundant water resources and a milder environment, while the warm–dry phases offered suitable sunlight and accumulated temperatures. The combination of these conditions was generally favorable for the survival and reproduction of species. Influenced by this climate, the number of CHS during this period significantly increased and expanded into surrounding areas.

③ Qin–Han period. Combining the characteristics of grassland vegetation in the paleoenvironmental studies of the northern foothills of the Tianshan Mountains [47] with the analysis of the TKP section pollen zones, where coniferous plants such as spruce and pine dominate [42], the Qin–Han period exhibited a distinct cool–wet climatic feature. The cold–wet climate resulted in relatively abundant water resources in Xinjiang, addressing the critical constraint of water for local development. Sufficient water resources ensured agricultural irrigation and the development of animal husbandry, enhancing human productivity and expanding the range of human habitation. On the basis of this favorable natural environment, the Silk Road flourished during the Qin–Han period, promoting frequent personnel mobility and cultural exchanges. This, in turn, drove significant socio-economic progress and further expanded the distribution of CHS.

④ Wei–Jin period. Based on paleoenvironmental studies of the northern foothills of the Tianshan Mountains [47] and pollen research from the Daxigou section in the headwaters of the Urumqi River [48], the climate during this period exhibited a transition from humid to warm–dry conditions. As the climate became drier and warmer, land desertification intensified, oasis areas continued to shrink, and the ecological environment gradually deteriorated. This adverse climatic shift posed significant challenges to human survival and development, leading to reduced human activities in some regions and the abandonment or relocation of CHS.

⑤ Sui–Tang period. The study of the Daxigou section in the headwaters of the Urumqi River [48] proved that the climate experienced obvious dry and wet changes. Among them, 1.4–1.31 ka BP was a warm–wet period, 1.31–1.10 ka BP was a dry–warm period. The prosperous period of the Tang Dynasty coincided with the warm–wet period with high humidity [49]. The warm and humid climate laid the material foundation for population growth, urban prosperity and cultural exchanges along the Silk Road. During this period, the number of CHS increased, the scale was expanded, and remarkable achievements were made in culture, art, science, technology, and others, which fully reflected the positive role of a suitable climate in promoting the development of human culture.

⑥ Song–Yuan period. According to pollen records from Bosten Lake [50] and the TKP section [42], the Xinjiang region experienced an arid period between 1000 and 1500 AD. The dry climatic conditions severely constrained agricultural production and the utilization of water resources, leading to a reduction in the scope of human activities. During this period, the density and scale of CHS decreased significantly.

⑦ Ming–Qing period. Integrating evidence from the Bosten Lake records [50], the accumulation of the Guliya Glacier [51], changes in the Tarim River flow [52], and pollen and stratigraphic studies of the Chaiwopu Basin [53], it was observed that the climate during this period underwent multiple cycles of alternating cold and warm, as well as dry and wet phases. Although frequent alternations of climate during this period imposed certain constraints on the CHS distribution, the peak emergence of CHS distribution was mainly attributed to the impetus of human activities.

⑧ Modern History. The pollen data from the TKP section [42], and the pollen and stratigraphic studies of the Chaiwopu Basin [53] indicate that the climate during this period generally exhibited a trend toward aridity. Meanwhile, there were periods of social unrest and frequent wars in modern and contemporary history. Moreover, since the time elapsed from then to now is relatively short, the number of CHS remaining to this day is rather limited.

3.2.2. Human Geography Factors

(1)

Political factors

In the process of regional historical development, political factors play a decisive role. For Xinjiang, the political environment in historical periods was the key driving force affecting the rise and fall of CHS. The development status of these sites depended on the strength of successive central governments and their control over the Xiyu. The Han, Tang, and Qing dynasties were typical periods when the central government effectively governed the Xiyu. In the Han Dynasty, the Protectorate of the Xiyu was established; during the Tang Dynasty, the Anxi Protectorate and the Beiting Protectorate were set up; and in the Qing Dynasty, the position of the Ili General was created [54]. These measures strengthened the governance of the Xiyu, significantly promoted the stable social and economic development of Xinjiang, and created conditions for the preservation of CHS. In contrast, during other historical periods, due to factors such as the weak national strength of the central government, frequent internal strife, or external interference, the central government was unable to exercise effective control over the Xiyu. As a result, the region was fragmented, with several ethnic-based regimes coexisting. This political instability led to social unrest and made large-scale construction activities difficult to carry out. Therefore, relatively few CHS were preserved.

(2)

Economic factors

Xinjiang, as a strategic economic location, has had its historical evolution deeply influenced by social and economic stability. In the Prehistory and Pre–Qin periods, due to the limitations of the level of productivity development and the early stage of social development, the scale of economic and trade activities was relatively limited. People mainly relied on gathering, hunting, and rudimentary primitive agriculture for survival, and the production surplus was extremely scarce [33]. This fundamentally restricted the occurrence of large-scale commercial exchange activities. Under such an economic form, the scope of commodity circulation was narrow, the trading forms were simple and sporadic, and a mature market system and trade network had not yet been formed. The limitations of economic activities also had a profound impact on the formation and preservation of CHS at that time. Owing to the lack of large-scale settlement construction, complex public building construction, and diverse places created by frequent commercial and social activities, the types of cultural sites were few. The CHS that survived from this period are mainly ancient tombs.

In the Qin–Han period, the world-renowned Silk Road began to emerge, with numerous types of CHS distributed along its route. The prosperity of the Silk Road in different historical periods directly influenced the shift in economic centers and the rise in economic and trade towns in Xinjiang. These changes in the economic pattern were closely related to the formation and distribution of cultural sites. In the Qin–Han period and Sui–Tang period, the rise in the Silk Road created favorable conditions for conducting land reclamation activities in southern Xinjiang [34]. The promotion of these activities laid a solid foundation for the economic prosperity of southern Xinjiang, establishing its central position in the regional economic pattern of Xinjiang at that time. Additionally, it prompted the preservation of a series of CHS related to land reclamation, economy, and trade in this region. For example, as a key node and transportation hub on the Silk Road, Gaochang benefited from the development opportunities brought by the Silk Road. Its social and economic development continued to progress, driving urban construction and expansion. The number of towns in Gaochang gradually increased from 7 in the early stage to 16 and even reached 22 in the Tang Dynasty [55]. Many buildings, trading places, beacon towers, and other structures formed during the process of urban development have been preserved as CHS.

By the mid-Qing Dynasty, the central government strengthened its effective control over Xinjiang, organizing the migration of people from the hinterland to regions such as Jimsar, Urumqi, and Ili to engage in land reclamation, farming, and border defense activities. Among the 24 reclamation districts established in Xinjiang, 14 were in Northern Xinjiang and 10 in Southern Xinjiang. There was a total of 126,700 reclamation settlers, with 91,000 in Northern Xinjiang, accounting for 71.8% of the total [35]. Thereafter, Northern Xinjiang gradually replaced Southern Xinjiang as the economic center of Xinjiang. This status as an economic center has continued into modern times. Most of the settlement sites from the Qing Dynasty onwards are still in use today, and many new civilian facilities such as transportation networks, factories, and water conservancy projects have been built, further consolidating its economic development advantages and cultural value.

(3)

Military war factors

In ancient times, Xiyu was a region where numerous states existed, and frequent conquests took place. From a geostrategic perspective, successive rulers of the Central Plains regarded the Xiyu as a crucial military–geographical zone, making military warfare a key variable influencing the CHS in the Xiyu [56]. The direct impact of warfare on CHS is evident in the outright destruction of their existence, with a strong correlation and significant fluctuation between the two. For instance, during the Wei, Jin, Southern and Northern Dynasties, Song, Yuan, and Ming dynasties, Xiyu became a focal point of contention between separatist regimes and nomadic tribes, leading to social unrest. The direct destruction caused by warfare greatly impacted the survival and development of CHS, resulting in a very limited number of CHS from this period. Warfare also indirectly influenced the distribution patterns and development trajectories of CHS. Wars often disrupt the local agro-pastoral economy, which is primarily based on subsistence farming and herding. This disruption leads to the decline and spatial displacement of oases, ultimately causing changes in the distribution pattern of CHS. During the Western Han Dynasty, when the Xiongnu and the Han Dynasty vied for control of the Xiyu, oasis city-states like Loulan were affected by the war. The water-conservancy facilities fell into disrepair, the farmland became desolate, and the original settlement sites were abandoned [54]. During the Qing Dynasty’s suppression of the Dzungar rebellion, the pastoral economy in the northern Xinjiang grasslands suffered heavy damage, leading to the abandonment of traditional nomadic campsites [57]. After the war, the Qing government engaged in land reclamation and development, causing the distribution of cultural sites to concentrate around the new reclamation sites, particularly in transportation hub cities and water sources such as Ili.

4. Discussion

4.1. Theoretical Implications

The spatial distribution of CHS in historical periods and their geographical influencing factors are key topics in historical geography. Previous studies on the spatial distribution of CHS have predominantly focused on static analytical frameworks, resulting in a significant research gap regarding their dynamic evolution within specific historical and environmental contexts, particularly in arid regions. This study addresses this gap by employing a spatio-temporal dynamic analysis framework to explore the regional distribution evolution of CHS in Xinjiang and their relationship with changes in natural and human factors. By integrating historical, environmental, and human dimensions, the findings reveal the dynamic trajectory of Xinjiang’s historical center of gravity and the changing patterns of CHS, while also interpreting regional historical development and human–environment interactions in arid regions. This research offers a novel perspective on the intrinsic logic of these processes, offering valuable insights and supplementary contributions to interdisciplinary studies in history, archeology, anthropology, and climatology. The details are as follows.

The analysis of CHS spatio-temporal distribution characteristics in historical periods further provides crucial material evidence for regional historical development. The dynamic spatio-temporal evolution of CHS essentially reflects the spatio-temporal development trajectory of regional history. Firstly, the chronological evolution of CHS in Xinjiang reflects the transformation of human social forms from nomadic to sedentary life [36]. Specifically, the types of CHS have gradually evolved from a single form dominated by early tombs to a structural system covering diverse remains such as settlements and architectural sites. The concentrated distribution of these CHS in specific spatial areas also indicates the transition to sedentary lifestyles. Moreover, the developmental trajectory of CHS provides empirical evidence that supports existing studies—highlighting the intrinsic link between Xinjiang’s historical evolution and the prosperity of the Silk Road [54,58]. A significant diachronic correlation is observed between the spatial distribution of CHS in Xinjiang and the developmental phases of the Silk Road during historical periods. Furthermore, the spatio-temporal evolution of CHS reflects the spatial tendencies and regional cultural characteristics of socio-economic development in Xinjiang. The developmental focus of CHS underwent a phased shift, starting from being highly mobile in the early stage, then moving to southern Xinjiang, and finally to northern Xinjiang. The shift in the distribution focus of CHS aligns with existing studies on the dynamic evolution of regional centers in Xinjiang, thereby offering new archeological–spatial substantiation to historical studies [34,55]. The shift in the distribution focus of CHS to southern Xinjiang was due to the strategic maintenance of the Silk Road by the “emphasizing the south over the north” policy during the Han and Tang dynasties, as well as the economic and trade ties with various Western countries and political stability. The subsequent shift to northern Xinjiang is closely related to the “emphasizing the north over the south” strategy implemented by the government after the Yuan Dynasty, large-scale immigration to northern Xinjiang for reclamation and garrison, and the transfer of economic and political centers. This phase shift reflects the dynamic adjustment of the strategic layout of the Central Plains dynasties, regional economic development, and ethnic interaction in different historical periods. By delving into the spatial distribution patterns of CHS, it can be found that their spatial concentration-diffusion model reflects the governance traditions of different ethnic groups, further corroborating the divergent characteristics between agrarian and nomadic communities [59,60]. During the Sui and Tang dynasties, the intensive sedentary characteristics of the agricultural civilization were reflected in the concentration of CHS. In the Qing Dynasty, the nomadic governance paradigm emphasized the management and utilization of a broader area, resulting in a wider scope of population and activities, which gave rise to the extensive diffusion characteristics of CHS.

The rise and fall of CHS in Xinjiang are essentially the result of the collaborative action of natural and human factors. Contrasting with the ongoing scholarly debate regarding the relative importance of natural and human factors across different regional contexts [6,10,11,27], this study demonstrates a distinctive arid zone pattern wherein natural factors (hydrology, topography, and climate) establish the fundamental framework for CHS distribution through their differential spatio-temporal combinations, but dynamic human activities continuously reshape it. When the central government effectively governed Xiyu (such as Han dynasty, and Sui–Tang period), the stable social economy order and relatively suitable climate promoted a positive coupling of the natural–human system. The irrigated agriculture and reclamation economy in the ancient oases along the Silk Road supported the growth in the number of CHS. Conversely, when the central government’s control declined (such as during the Song, Yuan, and Ming dynasties), the warming and drying climate exacerbated its ecological vulnerability. Coupled with the interruption of the Silk Road caused by political fragmentation, it ultimately led to the shrinkage of ancient oases and a sharp decrease in the number of CHS. This two-way interaction mechanism can be explained by the combined effects of hydrology, topography, and human activities. Existing research shows that the CHS distribution and human migrations in arid regions usually follow the typical pattern from downstream to mid-upstream areas [1,39,61], highlighting the core restrictive role of water resources. For example, during the warm and dry climates of the Wei, Jin, Song, and Yuan dynasties, CHS were mostly distributed in high-elevation areas close to rivers. However, this study further expands the research scope of CHS spatial shift and finds that with the improvement of productivity, the resource constraints gradually weakened. Human activities increasingly transcended geographical constraints, showing a reverse migration trend form mid-upstream to downstream areas. Specifically, against the backdrop of the arid climate from the Qing dynasties to Modern History, CHS were mostly concentrated in low-elevation areas near rivers. This discovery not only enriches the theoretical perspectives of migration research in arid regions but also emphasizes the necessity of dialectically viewing the dynamics of human migrations under the dual mechanisms of “environmental constraints–technological empowerment”.

4.2. Practical Implications

Research on the spatial distribution evolution of CHS and their geographical influencing factors in historical periods has significant practical guiding value. Taking Xinjiang, a typical arid region, as an example, this study systematically analyzes the spatial distribution patterns and evolution laws of CHS in different historical stages and delves deep into the interaction mechanisms between these sites and the natural and human geographical environments. It is noteworthy that the environment of arid regions is not static but has undergone a complex and dynamic evolutionary process. In historical periods, Xinjiang was not always an arid zone; rather, it gradually transformed into the arid regions we see today under the combined influence of factors such as climate change and human activities. Therefore, this study places particular emphasis on the dynamic relationship between the distribution of CHS and regional environmental evolution, and it advocates for the creative transformation of heritage values through adaptive reuse while examining the protection and development of these sites. This approach emphasizes both maintaining the spatio-temporal connection between the heritage sites themselves and their geographical environments and excavating the spatial carrier functions and historical and cultural significance of these sites in terms of being nodes on the Silk Road and inheriting ecological wisdom. In this way, these sites can not only continue the historical context of the arid region but also meet the development needs of modern society. The specific suggestions are as follows:

Firstly, a zoned conservation management strategy should be implemented. Based on the distribution characteristics of CHS and their surrounding environments, core protection zones and buffer zones can be demarcated. Priority protection must be given to core zones with high-density CHS distributions in arid regions, such as ancient river courses and piedmont oasis belts. Particular emphasis should be placed on ecological restoration around heritage sites, integrating environmental risk assessment into conservation strategies. Both core zones and buffer zones should adopt a “Cultural Heritage–Ecologically Sensitive Area” dual-control mechanism to develop ecologically compatible projects, thereby enabling proactive preventive conservation.

Secondly, it is essential to promote the coordinated development between CHS and regional planning. By leveraging technologies such as GIS-based spatio-temporal overlay analysis, the evolutionary patterns of CHS can be systematically translated into spatial constraints for territorial spatial planning. This captures the co-evolution of CHS with their environmental and socioeconomic settings, ensuring land-use planning internalizes heritage conservation imperatives through GIS-derived spatio-temporal analytics. Settlement layouts should then be optimized based on CHS distribution trends, environmental evolution, and historically critical infrastructure (e.g., transportation and water systems), to achieve synergy between heritage conservation and regional development.

Thirdly, sustainable revitalization of cultural heritage sites should be pursued. Based on the geographical features of CHS, such as proximity to rivers and transportation nodes, cultural corridors should be designed to create personalized and locally rooted cultural experience scenarios. Digital technologies should be employed to reconstruct ancient oasis landscapes, fostering ecological education and heritage tourism. Additionally, socio-economic factors should be incorporated into plan cultural tourism routes (e.g., the development of “Silk Road” thematic itineraries), creating a coherent network grounded in historical connections. Through community involvement and public education, residents’ awareness and participation in cultural heritage conservation should be enhanced. By disseminating knowledge about the historical environmental evolution of arid regions and the importance of CHS conservation, these efforts can promote cultural inheritance and sustainable socio-economic development in the region.

5. Conclusions

Taking Xinjiang as the research area, this study selects a total of 698 CHS from the national and autonomous-region-level lists of cultural relics protection units and categorizes them into eight historical periods. By utilizing GIS spatial analysis methods and qualitative analysis, the study analyzes the spatio-temporal distribution evolution of CHS and examines their geographical influence from both historical natural and humanistic perspectives. The following conclusions are drawn:

(1)

The CHS in Xinjiang features a distribution pattern of multicore agglomeration–linear extension. This pattern is supported by 13 key cities, four major areas with concentrated heritage sites, and the linear extension along the ancient Silk Road routes. The middle and northern route areas of the Silk Road are the most important belts for CHS distribution, accounting for 75.5% of all CHS. The spatial distribution of CHS in Xinjiang obviously correlates with the spatial distribution of the Silk Road.

(2)

CHS spatio-temporal distribution evolution is an indicator of regional historical development. The CHS development in Xinjiang across different historical periods shows a wave-like evolution feature of “three peaks and three valleys”. The three peak periods were the three crucial times when Xiyu was unified. The types of CHS have gradually evolved from early tombs to diverse forms, reflecting the transformation of human societies from nomadic to sedentary lifestyles. The center of gravity of Xinjiang’s CHS distribution has undergone a phased shift, starting from a relatively mobile state in the early stage, moving to southern Xinjiang, and then to northern Xinjiang. The shift aligns with the regional historical development center. Distributed along the northeast–southwest axis, CHS show initial concentration followed by diffusion, shaped by the governance characteristics of different ethnic groups, particularly the intensive practices of agricultural communities and the expansive tendencies of nomadic groups.

(3)

The CHS distribution shows a tendency to shift from high-elevation mountainous and hilly areas to low-elevation plain areas, and from high-slope areas to low-slope areas. The CHS distribution has shifted from being mainly in elevations of levels 3–5 to being mainly in elevations of levels 1–2. The slope distribution has continuously concentrated in the gentle slope areas of levels 1–2, with the proportion of sites in levels 1–2 increasing from 78.6% in the Pre–Qin period to 93.02% in Modern History. In Modern History, 93.02% of the CHS are distributed within the 10 km buffer zone of rivers, showing a significant water-source orientation. The Xinjiang region has experienced a process of aridification from cold–wet to temperate–dry. Climate change affects the CHS distribution pattern by influencing human production and living conditions.

(4)

Natural factors such as climate, landform, and water resources, as well as human-related factors such as regime changes, economic development, and military wars, are the driving factors for the emergence and spatial shifts in CHS in the study area. The analysis of influencing factors reveals a distinctive arid zone pattern, wherein natural factors establish the foundational framework for the basic distribution of CHS, while human activities drive its dynamic evolution. A spatial shift in site distribution—from downstream to mid-upstream areas, and subsequently from mid-upstream to downstream areas—further exemplifies this arid zone pattern, illustrating the relationship between natural resource limitations and adaptive human interventions.

This study mainly focuses on CHS that are national and autonomous region-level cultural relic protection units. There is still room for expanding the scope of the research to cover other types of CHS, such as heritage sites without hierarchical certification. In the future, we can conduct cultural relic surveys based on fieldwork and make full use of modern information technologies like big data and the Internet of Things to establish a more comprehensive CHS database. Moreover, regarding the analysis of influencing factors, although this study has integrated historical textual materials, it is necessary to further improve the comprehensive quantitative analysis ability of influencing factors, so as to more accurately grasp the relationship and comprehensive interaction mechanisms among various factors.