Methodologically, the GeoDetector was first applied to quantify the overall explanatory power of each influencing factor on the spatial distribution of industrial heritage, to identify statistically significant factors, and to analyze the interaction types among them. On this basis, both the OLS and GWR models were constructed to examine the spatial non-stationarity and local variations in the explanatory power of each factor, thereby providing a more comprehensive understanding of the complex influences shaping the spatial distribution of industrial heritage in Hebei Province.
3.4.2. OLS Model
Based on the 11 significant factors identified through GeoDetector screening, an OLS model was first constructed to examine multicollinearity among the explanatory variables and to assess whether the underlying model assumptions were satisfied. To evaluate linear relationships between variables, a Pearson correlation analysis was conducted (
Table 5). The results indicate varying degrees of correlation among most variable pairs, with an especially high correlation coefficient of 0.984 between population density and GDP, suggesting a strong risk of multicollinearity. This finding is further supported by the variance inflation factor (VIF) test, in which both variables exhibit VIF values well above the threshold of 7.5 (
Table 6), indicating that removal is warranted [
56]. Given that GDP shows substantially stronger explanatory power than population density in the GeoDetector results, GDP was retained while population density was excluded from the model. After re-estimation, the VIF values of all remaining variables fell below 7.5, indicating that multicollinearity was effectively controlled.
The OLS diagnostic results are presented in
Table 7. The Jarque–Bera test is statistically significant (JB = 18.82,
p < 0.001), indicating that the residuals deviate from a normal distribution. The Breusch–Pagan test is not significant (BP LM = 15.73,
p = 0.108), whereas the White test is significant (LM = 92.59,
p = 0.014), suggesting the possible presence of heteroskedasticity or model misspecification. In addition, the Moran’s I statistic for the OLS residuals is 0.35 (
p < 0.001), showing significant positive spatial autocorrelation. This result indicates that the OLS model has limited ability to capture spatial dependence and spatial non-stationarity in the data.
Overall, OLS proves useful for identifying multicollinearity among explanatory variables, but its ability to capture spatial effects remains limited. To further investigate the spatial variability of influencing factors and to assess the extent to which spatial dependence affects model performance, it is necessary to introduce the spatial lag model (SLM), the spatial error model (SEM), and the geographically weighted regression (GWR) model with higher spatial resolution for comparative analysis.
3.4.3. GWR Model
After removing variables with strong multicollinearity, this study applied geographically weighted regression to the remaining ten explanatory variables to explore regional differences in the strength and direction of their effects. An adaptive kernel bandwidth was adopted, and the optimal bandwidth was determined by minimizing the corrected Akaike Information Criterion (AICc), resulting in a neighborhood size of 124. Compared with the OLS model, the GWR model shows a substantial improvement in performance, with the AICc reduced to 194.02 and the R2 increased to 0.8680, indicating a markedly enhanced explanatory power.
To examine the sensitivity of model performance to bandwidth selection, this study conducted a comparative analysis using alternative bandwidths within approximately −20%, −10%, and +10% of the optimal value, corresponding to 100, 112, and 136 neighboring units. The results indicate that smaller bandwidths lead to improved model fit (
Table 8), as reflected by lower AICc values and higher R
2 and adjusted R
2. However, the Condition Number exceeds 30 under these settings, suggesting an increased risk of local multicollinearity. In contrast, larger bandwidths provide greater model stability but are associated with reduced explanatory power. Importantly, the overall spatial patterns of the regression coefficients remain largely unchanged across different bandwidths, with consistent spatial differentiation trends observed. This indicates that the model is structurally robust in terms of spatial configuration. Balancing model fit and stability, a bandwidth of 124 was ultimately selected for the main analysis.
To further identify the types of spatial effects, this study conducted a comparative analysis of the OLS, spatial lag model (SLM), spatial error model (SEM), and GWR (
Table 9). The AIC values of SLM and SEM (228.48 and 220.13) are lower than that of OLS, and their R
2 values are higher (0.8000 and 0.8121), indicating the presence of spatial lag and spatial error effects in the data. Although these two models improve overall statistical performance, they rely on globally fixed parameters and therefore cannot capture spatial heterogeneity in the effects of explanatory variables. By contrast, GWR achieves the lowest AICc and the highest R
2, suggesting that spatial non-stationarity plays a more central role in explaining the spatial distribution of industrial heritage.
The results of residual spatial autocorrelation further highlight the differences among the models (
Table 10). The OLS residuals exhibit a significantly positive Moran’s I value (0.35,
p < 0.001), indicating pronounced spatial clustering. In contrast, the residual Moran’s I values for the SLM and SEM are −0.03 (
p = 0.248) and 0.04 (
p = 0.096), respectively, both of which are statistically insignificant. This suggests that these two models effectively address the systematic spatial dependence arising from spatial lag effects and spatially correlated errors. The residual Moran’s I of the GWR model remains significantly positive (0.21,
p < 0.001), yet it is approximately 40% lower than that of the OLS model. This indicates that although GWR does not fully eliminate residual spatial clustering, it captures a substantial portion of the spatial heterogeneity that is not identified by OLS, thereby markedly enhancing the model’s ability to explain regional differences.
In the GWR model, statistical significance was assessed using local t-values, calculated as the coefficient divided by its standard error, with |t| > 1.96 indicating significance. The results (
Table 11) show that railway density and the density of nationally protected cultural relic sites exert statistically significant effects across the entire province, and the regression coefficients of railway density are markedly higher than those of other variables. In contrast, elevation, slope, mineral resource density, traditional village density, road density, A-level scenic spot density, and water system density exhibit significance only in limited areas, reflecting pronounced spatial heterogeneity. GDP does not reach statistical significance anywhere in the province and therefore fails to provide a stable explanation for the distribution of industrial heritage. Based on these findings, regional mechanisms are further analyzed from three dimensions: transportation conditions, the natural geographic environment, and cultural resources.
- (1)
Transportation Factors
As the backbone of the modern industrial transport system, railways directly shape the efficiency of raw material inflow and product outflow. Industrial belts often develop along railway corridors, making them a foundational driver of industrial site selection and spatial clustering. The GWR results indicate that railway density exerts a statistically significant effect across the entire province, with coefficients ranging from 0.3030 to 0.6969 (
Figure 10a). The northern and eastern regions of Hebei show notably higher coefficients, suggesting that railways play a particularly strong role in promoting industrial heritage clustering in these areas. These regions represent the birthplace of modern railways and industrialization in China, where railway construction directly stimulated the development of mining, metallurgy, and port-related industries, ultimately shaping a railway-oriented pattern of industrial heritage distribution [
57]. Coefficients in the central and southern cities, including Cangzhou, Hengshui, Xingtai, and Handan, are relatively low, indicating weaker explanatory power of railways. Overall, the influence of railways increases from south to north, reflecting the spatial evolution of Hebei’s industrial heritage: northern railway- and port-based industrial sites are closely tied to early railway development, while the industrial heritage patterns in the southern region have been shaped more profoundly by cultural context and historical events.
Road networks serve as crucial channels for regional economic interaction and product circulation. Road density reflects local transportation accessibility, which plays an important role in shaping industrial development as well as the preservation and reuse of industrial heritage. The GWR results show that road density is statistically significant mainly in the central and southern plains of Hebei, with coefficients ranging from 0.1309 to 0.3518 (
Figure 10b). This indicates a significant positive relationship between road accessibility and industrial heritage in areas where traditional industries are concentrated and urbanization is relatively advanced, meaning that districts and counties with better road access tend to develop industrial clusters and retain more industrial relics. Meanwhile, the southwestern Taihang Mountains, northern mountainous regions, and eastern coastal areas do not exhibit statistical significance, suggesting that road conditions have no stable relationship with the spatial distribution of industrial heritage in these areas. In the northern mountainous areas, the terrain is complex and the population is sparse. Under national spatial strategies, these regions have long served as ecological barriers and leisure–tourism zones [
58]. As a result, road networks are primarily oriented toward rural–urban connectivity and tourism travel, and their spatial pattern does not show a stable correspondence with the formation of industrial heritage. In coastal cities such as Tangshan and Qinhuangdao, early industrial development relied mainly on railways and ports, so the road network did not play a determining role in shaping the distribution of industrial heritage. With ongoing industrial restructuring, the function of road networks has increasingly shifted from supporting traditional industries to serving coastal tourism and port-related logistics, further weakening their statistical association with the spatial pattern of industrial heritage.
- (2)
Natural Geographic Factors
Elevation reflects the combined influence of topography, climate, and transportation accessibility, serving as a key constraint on industrial layout. Low-altitude areas, characterized by flat terrain, convenient transportation, and favorable development conditions, are more suitable for industrial activities. High-altitude regions, with rugged terrain and high construction costs for infrastructure, are less conducive to industrial development and the preservation of industrial heritage. The GWR results show that the effect of elevation reaches statistical significance only in the southwestern Taihang Mountains, with coefficients consistently negative and ranging from −0.5999 to −0.1870 (
Figure 11a). Notably, although the western mountainous areas of Shijiazhuang and Handan, along the eastern foothills of the Taihang Mountains, contain a large number of industrial heritage sites, their regression coefficients are among the lowest. This phenomenon is not primarily caused by topographical conditions but rather by historical policy factors. During several key historical periods such as the War of Resistance Against Japanese Aggression, the War of Liberation, and the early years of the People’s Republic of China under the First Five-Year Plan and the Third Front Construction, a large number of military-industrial projects were established in mountainous and peripheral regions, forming clusters of red industrial heritage. To enhance concealment, many factories were located in valley areas at relatively low elevations, resulting in a strong negative correlation between elevation and the spatial distribution of industrial heritage in these regions.
Slope represents terrain variability and is a key geographic factor affecting the feasibility and cost of industrial construction. The GWR results indicate that the significant influence of slope is spatially concentrated in the southwestern Taihang Mountains, similar to the pattern observed for elevation (
Figure 11b). Within the significant region, slope coefficients are distinctly positive, ranging from 0.1696 to 0.5681. This suggests that areas with more rugged terrain tend to host more industrial heritage sites. This positive association does not imply that steep slopes inherently attract industrial construction; instead, it reflects historical industrial deployment strategies. Mountainous environments offer natural concealment and defensive advantages, which made them preferred locations for military, mechanical, and telecommunications industries during wartime and planned-economy periods.
Water system density reflects the spatial distribution of hydrological conditions and has a potential influence on early industrial site selection and production water demand. The GWR results show that the influence of river density is extremely limited, reaching statistical significance only in the southwestern Taihang Mountains, while most other regions show no significant effect (
Figure 11c). In the significant areas, the coefficients are small, ranging from −0.1788 to −0.0628, indicating a weak negative association. Overall, river density exerts only a minor impact on the spatial distribution of industrial heritage.
Mineral resources provided the material foundation for Hebei’s early industrial development. Mineral resource density reflects spatial differences in the availability of raw materials for heavy industry and is therefore an important natural factor shaping the formation and distribution of industrial heritage. The GWR results show that the influence of mineral resource density is statistically significant in central Hebei and parts of the north, while most southern areas do not reach significance. Coefficients are uniformly positive, ranging from 0.0828 to 0.5759 (
Figure 11d). The strongest effects occur in central Hebei, which serves as a key hub linking the Taihang Mountain resource belt with the coastal industrial and port zones. On the one hand, abundant mineral resources supported the growth of heavy industry; on the other hand, the region’s advantageous position facilitated the collection, processing, and transport of raw materials. As mining operations, smelters, repair workshops, and related facilities accumulated over time, the region developed a pronounced positive relationship between mineral resource density and industrial heritage distribution.
- (3)
Cultural Factors
Traditional villages are closely associated with handicrafts, subsistence industries, and early commercial activities. Regions with a higher density of traditional villages often contain early forms of mining, brewing, and textile production, which later evolved into industrial heritage sites. The GWR results show that the influence of traditional village density is statistically significant mainly in south-central Hebei, with coefficients ranging from 0.0721 to 0.4732 (
Figure 12a). This region hosts a large concentration of traditional villages, where village-based handicraft and proto-industrial systems emerged early, providing the foundations for subsequent industrial development; hence its strong positive association. By contrast, the northern mountainous areas and the eastern coastal region are dominated by modern, mechanized industries, with relatively few traditional handicraft remnants, resulting in no statistically meaningful correlation with industrial heritage patterns.
The density of A-level scenic spot reflects the intensity of regional tourism development and the clustering of landscape resources, and is generally regarded as a potential condition for promoting the integrated development of industrial heritage and tourism. The GWR results indicate that statistical significance occurs only in parts of south-central Hebei, while northern and coastal areas show no significant effect (
Figure 12b). In the significant regions, all coefficients are negative, ranging from −0.3517 to −0.1430. This negative relationship reflects the spatial structure of industry and landscape in south-central Hebei: industrial heritage tends to cluster in old industrial cities, whereas A-level scenic sites are primarily natural or historical landscape attractions. Their spatial mismatch leads to a negative spatial association between the two.
The density of national key cultural relic protection units represents the degree of historical accumulation and the concentration of traditional cultural resources. Regions with a deep cultural heritage often achieved early industrial development and therefore retain more industrial heritage. According to the GWR results, this factor is statistically significant across the entire province, with consistently positive coefficients ranging from 0.1940 to 0.4574 (
Figure 12c). Higher coefficients appear in southern Hebei, particularly in Hengshui, Xingtai, and Handan, where historical sites and industrial heritage coexist and traditional and industrial cultures reinforce each other. Coefficients are lower in the north, suggesting weaker spatial associations. Overall, the influence of this factor decreases from south to north, indicating that industrial heritage and traditional culture are more closely intertwined in the southern part of the province.