1. Introduction
Industrial heritage is a vital record and witness of urban development and the progress of human civilization in the past 200 years [
1]. As an essential carrier of inherited industrial civilization, industrial heritage witnesses the industrial development process of a country or region, which has immense value in history, technology, socio-culture, and art [
2]. In 2003, the International Committee for the Conservation of Industrial Heritage (TICCIH) adopted the renowned “Nizhny Tagil Charter.” Serving as a foundational document in the field of industrial heritage conservation, the charter explicitly states that industrial heritage consists of the remains of industrial culture, which possess historical, technical, social, architectural, or scientific value [
3]. In 2012, TICCIH passed the “Taipei Declaration.” Recognizing the distinct industrial development processes in the Asian region compared to the Western world, the definition of industrial heritage in Asia is considered broader, encompassing not only buildings, machinery, workshops, factories, mines, and refined processing sites but also warehouses, storage facilities, energy production, transmission, use, transportation, and all social activity sites related to industry [
4]. The varied definitions of industrial heritage in different regions reflect a fundamental consensus in today’s international society. Subsequently, the effective conservation and revitalization of industrial heritage have gradually become a globally shared concern.
Currently, most countries are in the stage of urban stock renewal and development for socio-economic development and extended urban culture, while the drawbacks of the construction and layout of most traditional industrial cities are becoming increasingly prominent [
5,
6,
7,
8]. Once-prosperous industrial heritage has become the primary focus of urban renewal [
9,
10,
11,
12]. NIH sites should not be indiscriminately demolished simply because their original political, economic, and cultural functions have changed. They carry the essence of urban culture and are an integral part of material cultural heritage [
13]. In the post-industrial era, modern means are used to maintain the stability of the spatial distribution of industrial heritage, which is conducive to preserving and transmitting the unique history of different geographical spaces [
14]. Meanwhile, the conservation and reuse of industrial heritage [
15,
16,
17,
18,
19] will be advantageous to the sustainable development of industrial cultural heritage.
The current scholarly inquiry into historical sites and cultural heritage spans micro, meso, and macro scales. Within the context of digital humanities, digitization technologies, such as historical cultural repositories, have been widely applied at the micro- and meso-scales in the realm of heritage conservation [
20]. Various aspects have been explored, employing a data visualization perspective for visual element recognition [
21,
22], capturing multisensory techniques [
23], and developing heritage information databases [
24]. At the macro level, with the advancement of remote sensing and geographic information systems (GISs), the spatial distribution of historical landmarks has been quantified [
25]. In recent years, the geospatial data visualization techniques of GISs have gained extensive traction in the realm of both tangible and intangible cultural heritage. This application spans resource management, spatial distribution, and addressing regional disparities in the context of heritage conservation [
26,
27,
28,
29,
30]. ArcGIS, serving as a geographic information platform, incorporates a variety of spatial analysis methods. Methods, such as buffer analysis, overlay analysis, and spatial matching, have been widely used to explore the spatial relationships between nonmaterial cultural heritage and various factors, including topography, watersheds, population, roads, and economic development [
31,
32,
33]. Techniques such as kernel density analysis, nearest neighbor index, and spatial autocorrelation analysis offer an intuitive reflection of the geographical distribution of urban industrial heritage, enabling an objective analysis of its spatial characteristics [
32,
34,
35]. The application of GIS technology not only facilitates a comprehensive understanding of the current status of industrial heritage within specific regions but also provides a broader information base and scientifically derived analytical results for urban planning [
36,
37]. Thus, the application of spatial analysis methods in studying the distribution characteristics of cultural heritage presents a novel perspective for industrial heritage conservation in this study [
38].
The repurposing of industrial heritage has been studied for many years, including many countries, such as the United Kingdom and America. They have been made to address urban challenges in the post-industrial era [
39,
40,
41,
42]. Europe and America have placed significant emphases on developing evaluation and recognition standards for industrial heritage [
43,
44] and studying its universal value [
45,
46,
47]. Building upon this foundation, they have classified and protected industrial heritage sites [
48]. The trend of reusing industrial heritage was also explored in China [
49,
50]. Studies on industrial heritage characteristics have primarily focused on the temporal and spatial features of regional [
51,
52] and individual sites [
15,
18,
52] in China. Meanwhile, the preservation and reuse models of industrial heritage were studied in the late 1980s [
16]. These factors have stimulated numerous theoretical and practical studies on industrial heritage preservation and reuse. Various models for preserving and utilizing industrial heritage have been identified, including industrial museums, landscape park transformation, commercial development, and creative park utilization models [
53]. Additionally, some specific preservation and utilization models have been proposed, such as the regional protection model, holistic protection model, and partial protection model for physical industrial heritage groups [
54]. Although the spatial distribution characteristics and related influencing factors of the first four batches of NIH sites have been analyzed [
55], more research is needed on the current status of industrial heritage reuse. This lack of research hinders a comprehensive understanding of the spatial and typological variations in NIH site reuse. Moreover, there is a need for analysis and research on the intensity of factors influencing the spatial differentiation of industrial heritage reuse.
Two main issues can be identified based on the analysis of the current research status of industrial heritage. First, research on China’s NIH sites has primarily focused on the regional and individual levels, and a comprehensive understanding at the national level is needed. Second, there needs to be more exploration of the NIH sites’ spatial structure and geographical distribution patterns, as well as the correlation between the spatial distribution of industrial heritage and their conservation and reuse models in China. This research addresses three key directions. The first direction is to systematically investigate the spatial distribution types of the current five batches of NIH sites in China according to industrial types and geographical locations. The second direction is to investigate the progress of NIH site conservation and reuse, analyze the current distribution characteristics and patterns of reuse, and explore the future direction of industrial heritage conservation and reuse. The third direction involves using geographic probes to quantitatively analyze the influencing factors of spatial differentiation in the reuse of industrial heritage sites. This study can provide a quantitative database, guidance, and direction for NIH conservation and reuse.
5. Discussion
The protection and reuse of NIH sites vary according to different regions. By clearly understanding the overall distribution pattern of industrial heritage and the preference patterns for reuse in different regions, as well as exploring the underlying factors contributing to the current pattern, better sustainable protection and reuse of heritage sites can be achieved. In this study, three significant findings were obtained.
First, an analysis of the overall spatial distribution pattern of NIH sites was conducted. China’s NIH sites exhibit a clustered distribution with a high degree of spatial imbalance. The overall quantity of NIH sites decreases from the eastern coastal areas to the western inland areas, showing a decreasing trend from east to west. The diverse requirements of various industrial productions lead to regional disparities in the distribution of industrial activities, giving rise to distinctive regional characteristics in industrial development. This is consistent with previous research findings [
55]. This analysis covered the distribution of reuse projects for NIH sites and summarized the current status of industrial heritage reuse using an established database. Previous studies primarily focused on theoretical exploration [
18,
53] or industrial heritage in specific regions [
43,
51], lacking comprehensive statistical analysis of the current status of site reuse.
Second, the quantity and directions of reused sites were visualized and analyzed spatially. Regarding regional differences, the eastern region, compared to the central and western regions, has a higher number of NIH public cultural facility protection and reuse projects, with museums being predominant. The industrialization development of NIH sites is mainly concentrated in the eastern region, with cultural tourism and creative park models as the main development modes. Overall, the level of protection and reuse of NIH sites in the eastern region is higher than that in the central and western regions, especially in terms of capital industrialization. Moreover, the industrialization of NIH sites in the eastern region focuses on cultural and creative industries, with significant involvement in cultural tourism. This aligns with some research, indicating that the eastern region, being economically developed with high population density and flow, provides market advantages for NIH sites, resulting in a higher degree of industrialization compared to the central and western regions [
78]. Additionally, the levels of public cultural spatial protection and reuse of NIH sites decrease from east to west in the eastern, central, and western regions. Economic disparities between regions inevitably lead to differences in the level of public cultural services. The eastern region, being economically developed with a better urban development environment, exhibits the highest quantity and most diverse types of public cultural spatial protection facilities, emphasizing urban leisure, with a greater number of public recreation spaces.
Last, the geographic detector model indicates that natural geography, socio-economic factors, tourism resources, and government support play crucial roles in determining the spatial differentiation of reused sites for NIH. Government support and policy guidance play a dominant role, while natural geographic factors determine the layout of industrial site selection. Economic conditions and tourism development drive the transformation of industrial heritage, with the government playing a crucial role in promotion, management, and regulation. This aligns with similar conclusions from studies on influencing factors of geographic spatial distribution. When selecting factors influencing spatial distribution for reused industrial heritage sites, it is essential to consider historical and cultural value, geographic location and environmental conditions, urban development planning, social needs and market potential, technological and economic feasibility, cultural protection policies, and societal awareness [
2,
5,
81]. These factors will impact the spatial layout and functional positioning of reuse projects to ensure a balance between historical preservation and urban development.
This study holds significance for research on the regeneration and reuse of industrial heritage sites in two aspects. First, the current research on industrial heritage mainly focuses on aspects such as heritage preservation and utilization, often conducted at the level of individual heritage sites. There is a lack of visualized analysis based on a large amount of data regarding the reuse conditions and geographical spatial attributes of industrial heritage sites. Therefore, this study, by understanding the patterns of industrial heritage reuse across different categories, provides evidence for overall regeneration and utilization planning. Second, by employing a geographic detector to investigate the role and distribution mechanisms of NIH reuse spatial formation, this research contributes to the analysis of NIH utilization potential from a spatial perspective. The framework for assessing the influencing factors constructed from different dimensions can also be applied to the study of reuse potential in other tangible (such as ancient buildings, cave temples, stone carvings, and murals) and intangible cultural heritage (oral traditions, folk literature, folk activities, performing arts, etc.). This can aid in establishing a more comprehensive framework and indicator system for assessing reuse potential.
However, this study has some limitations. First, when investigating the patterns of industrial heritage reuse at the national level in China, the classification of reuse directions may not be entirely accurate and comprehensive. Particularly in recent years, with the advent of big data and the Internet era, the direction of heritage transformation has become more digitized and intelligent. In future research, more studies are needed to conduct a more detailed classification of the patterns of industrial heritage reuse. Second, the study did not delve into the specific characteristics and attributes of the current reuse status of each site, which could impact the interpretative power of influencing factors. Future research should encompass the historical culture, structure and mechanism, architectural features, folk culture, and more related industrial sites to better explore the spatial distribution mechanism of their reuse.
The following aspects should be considered in subsequent research. This study explores the spatial distribution and determinants of NIH site reuse at the macro scale. As industrial heritage projects continue to be enriched, investigations could further explore the potential reuse of sites at micro scales, such as at the city and county levels. With technological advancements, diverse consumer patterns, and the introduction of new policies, more diverse and scientifically grounded factors should be selected for the study of reuse driving forces in future research. Specifically, GIS spatial analysis and visualization tools could be collaboratively employed for the digital collection, storage, management, display, and dissemination of heritage textual, visual, auditory, and video data. Establishing a dynamic resource database and a modernized management service platform is crucial. Subsequently, based on the database, constructing a multidimensional indicator system can be undertaken to explore the potential and direction of reuse. On this basis, targeted strategies for heritage reuse development can be proposed, aiming to provide a reference for the sustainable construction of cultural heritage.