Heritage Corridor Construction in the Sui–Tang Grand Canal’s Henan Section Based on the Minimum Cumulative Resistance (MCR) Model

Abstract

Current research on heritage corridors predominantly focuses on linear heritage in Europe and America, while studies in Asia urgently need to be expanded. This study investigates China’s linear heritage. Based on the minimum cumulative resistance (MCR) model, it conducts heritage corridor construction for the Henan section of the Sui–Tang Grand Canal, and reveals the following: (1) A total of 252 heritage sites were classified into three categories: canal hydraulic heritage (13.5%), canal settlement heritage (21.4%) and related heritage (65.1%), exhibiting a “local clustering under global dispersion” pattern with a core–secondary–edge structure. (2) The influence of natural–social resistance factors was ranked as follows: elevation > roads > land use > slope. Interwoven corridors were simulated by GIS and optimized to four primary corridors with multiple secondary corridors. (3) The transverse zone of the primary corridors was stratified into core area (0–10 km from the centerline), buffer area (10–25 km), and influence area (>25 km) with a total width of 25–30 km. The longitudinal section was partitioned into four subsections based on hydrological continuity and heritage density. Then, a tripartite conservation framework characterized by “heritage clusters–holistic corridor–transverse stratification and longitudinal section” was proposed. It aimed to provide insights into methodologies and content structuring for transnational linear heritage (e.g., the Silk Road and the Inca Trail).

1. Introduction

Since the late 20th century, global cultural heritage protection has gradually shifted from the “frozen preservation” of individual sites to “systematic development”, in which the continuity of cultural lineages and functional synergies was emphasized. This shift led to the emergence of the heritage corridor concept, which was regarded as a spatial carrier of linear geographic units, linking dispersed heritage sites via greenway networks, integrating cultural heritage preservation, ecological conservation, and recreational functions. The concept first emerged in the United States with the official designation of the Illinois and Michigan Canal National Heritage Corridor by Congress in 1984 [1]. Subsequent research expanded in scope, evolving from early conceptual and managerial frameworks [2] to encompass diverse issues such as tourism impact assessment [3], community participation mechanisms [4], multi-level network analysis [5], and sustainable development strategies [6], which enriched the theoretical basis of heritage corridors, highlighting their role as complex systems integrating cultural, economic, and ecological functions. In 2001, Wang Zhifang and Sun Peng [7] introduced the concept of heritage corridors into China, promoting extensive theoretical and practical explorations tailored to local contexts. Theoretically, relative research focused on definitional interpretations [8], carrier identification [9], and spatial planning frameworks [10]. Methodologically, Yu Kongjian et al. [11] introduced suitability analysis into domestic research, promoting the application of quantitative spatial analysis. Scholars such as Wang Sisi [12], Sha Di [13], and He Ding [14] further advanced the use of techniques including AHP and GIS. Practically, studies addressed iconic linear heritage systems such as the Tea Horse Road [15], the Great Wall [16], the Shu Road [17], and the Yellow River [18], focusing on corridor construction [19], tourism resource development [20], and heritage conservation strategies [21]. These efforts collectively contributed to the development of a heritage corridor paradigm aligned with China’s cultural and conservation needs.

Although existing research on heritage corridors has yielded considerable results, several underlying issues have yet to be thoroughly explored. First, concerning the corridor’s spatial structure, there has been limited scientific quantification of corridor widths and exploration of differentiated segmentation, which has constrained the transition from macro-level strategy to the implementation of refined management. Second, methodologically, although tools such as GIS and AHP are widely applied, interdisciplinary collaboration remains insufficient. There is a critical need to incorporate theories and approaches from historical geography, landscape ecology, and urban–rural planning to better couple the historical functions, cultural attributes, and spatial characteristics of specific heritage sites, which is key to enhancing the depth and applicability of heritage corridor research.

The minimum cumulative resistance (MCR) model [22] is a key tool for simulating species migration paths in landscape ecology. Its core principle is to quantify the cost of spatial resistance between the “source site” and the target site, and generate a “least-cost resistance” path to simulate the optimal spatial orientation of ecological corridors. Recently, MCR has been introduced into the field of cultural heritage [11]. This approach considers heritage sites as “source sites” and views geography, construction, and development as “resistance surfaces”, so as to simulate the spatial relevance of heritage via the least-cost path analysis. For instance, Yang Peifeng et al. [23] implemented spatial clustering analysis and the MCR model in Dazhangxi (Fuzhou section), established a three-tier conservation network (corridor–node–cultural zone), and optimized the holistic preservation pattern of linear cultural heritage. Du Yifan et al. [18] proposed a “cultural transmission-spatial grading” framework for the Yellow River Basin Heritage Corridor. They utilized the Cultural Corridor Spatial Potential Model (CCSPM) to quantify cultural radiation intensity and integrated the MCR model with the GIS fishing net tool to delineate core corridors, secondary corridors, and radiation areas. Collectively, the application of the MCR model in cultural heritage has established a fixed research workflow with “heritage source identification—least-cost path simulation—conservation strategy proposal”.

As China’s most representative linear cultural heritage, the Grand Canal was inscribed on the UNESCO World Heritage List in 2014 and is regarded as a critical testing ground for the localization of heritage corridor theory [24]. The Henan section of the Sui–Tang Grand Canal represents a key segment within the Grand Canal system, characterized by its historical origin and functional continuity. Its hydrological foundation dates back to the pre-Qin period, was systematically expanded during the Sui Dynasty, and continuously optimized in the Song Dynasty. It served as the canal network’s crucial transport hub and source during the Sui–Tang periods. This section encompasses seven UNESCO World Heritage segments and 262 nationally protected sites, including representative large-scale granaries such as the Hanjiacang and Huiluocang warehouses, which materialize the canal’s pivotal role in imperial grain storage and transport. Certain segments, such as the Yongji Canal in Hua County, still perform irrigation and flood control functions today. Current research by Chinese scholars on the Henan section of the Sui–Tang Grand Canal has focused primarily on aspects such as heritage value identification [25], spatial patterning along the corridor [26], and conservation strategies [27]. For instance, You Tao et al. [28] established a heritage spectrum of “river remnants + hydraulic facilities + canal towns” by analyzing heritage elements of the Tongji Canal section of the Sui–Tang Grand Canal. Shang Chunfang’s [29] spatial reconstruction of Luoyang City revealed that the canal fostered a dual-core spatial structure—a political core in the northwest and an economic core along the riverside—along with associated commercial networks. Li Jinglan reviewed the historical evolution and heritage composition of the Xingyang Ancient City segment of the Tongji Canal, exploring strategies for integrated conservation and utilization based on heritage corridor theory. Overall, the existing studies on this section tend to focus spatially on scattered heritage sites, individual canal segments [30], or urban nodes along the route [31], while systemic cultural network analysis has received comparatively less attention. Research specifically addressing heritage corridors remains an area requiring further in-depth exploration.

This study takes the Henan section of the Sui–Tang Grand Canal as its research object, integrating a multi-disciplinary theoretical framework from historical geography, landscape ecology, and urban–rural planning. Firstly, based on the MCR, it constructed the corridor simulation framework of heritage source identification–resistance surface calculation–corridor network generation [32]. Then it further delineated “corridor transverse zoning–corridor comprehensive longitudinal section”. The novel aspects are twofold: First, a dual-dimensional evaluation framework from the aspects of cultural and eco-social value was established for canal heritage. The analytic hierarchy process (AHP) and the kernel density method were employed to quantify heritage node values and identify high-potential cultural core areas. The geographical detector (GeoDetector) was then introduced to analyze spatial differentiation patterns of ecological and social resistance [33]. Second, after completing corridor simulation and grade optimization, it further defined the spatial hierarchy and divided the integrated segment area to form a comprehensive research system of heritage corridors. This methodology is anticipated to offer a transferable framework for holistic conservation of transnational linear heritage systems (e.g., the Silk Road, Inca Sacred Trail), while also contributing to more systematic approaches for the conservation of historical and cultural spaces.

It addressed five core research questions:

(1)

Spatial differentiation patterns: What are the spatial characteristics of heritage resources in the Henan section of the Sui–Tang Grand Canal?

(2)

Resistance assessment: How to quantitatively assess the spatial constraint effects of socio-natural composite resistance factors on heritage corridor formation?

(3)

Corridor network simulation: How to spatially simulate heritage corridors by using the minimum cumulative resistance (MCR) model?

(4)

Spatial partitioning of the corridor: How to advance from established corridor routes to partition the corridor space transversely and longitudinally?

(5)

Conservation strategies: How to propose a holistic-differentiated conservation strategy for the heritage corridor system?

2. Materials and Methods

2.1. Study Area

The Sui–Tang Grand Canal, together with the Beijing-Hangzhou and Zhejiang-East Canals, forms China’s Grand Canal system [34]. It could be traced back to the pre-Qin Honggou system, systematically expanded during the Sui Dynasty (581-618 CE), and continuously optimized from the Tang (618–907 CE) to the Song (960–1279 CE) Dynasty, ultimately forming a Luoyang-centric longitudinal canal system [35]. In Henan Province, the canal splits into two branches: The Yongji Canal (227 km) retains intact channel morphology and also sustains flood control, irrigation, and ecological functions. The Tongji Canal (331 km) exhibits spatial contrasts: active waterways persist in Luoyang, Zhengzhou, and parts of Shangqiu (e.g., Luoyang’s Yellow River tributary), while silted subterranean relics are present in other regions [36]. Millennia of functional evolution have stratified its landscape into surface waterways and underground archeology. This canal sustains multilayered heritage, with 7 UNESCO World Heritage segments and 262 nationally protected sites, which connect 4 ancient capitals and 7 historic cities. Additionally, it has given birth to numerous intangible cultural heritage (ICH) elements.

The spatial scope of this study was delineated according to the Implementation Plan for the Protection, Inheritance, and Utilization of the Grand Canal Culture in Henan Province, including its defined core area with forty counties and Expansion Area across nine Prefecture-level Cities’ Administrative Region (Luoyang, Zhengzhou, Kaifeng, Shangqiu, Jiaozuo, Xinxiang, Hebi, Anyang, and Puyang) (Figure 1a). It covers 38.8% of the province’s area, but concentrates 62.05% of the province’s heritage resources (

Table 1. Distribution of heritage types: Henan Province and Canal Expansion Zone.

Heritage Types/Number (Units)	Henan Province	Canal Expansion Zone	Percentage (%)
National-level Historic and Cultural Cities	8	7	87.50%
National-level Historic and Cultural Towns	10	3	30.00%
National-level Historic and Cultural Villages	9	2	22.22%
National Cultural Relics Protection Units	418	259	61.96%
Provincial Cultural Relics Protection Units	1161	732	63.05%
National Intangible Cultural Heritage	125	71	56.80%
Total Heritage Count	1731	1074	62.05%
Area (10,000 km2)	16.7	6.480143	38.80%

, Figure 1b). It covers the northern part of Henan, where Temporal Overlapping Features of Ancient and Modern is most significant, so it can systematically reflect the demand for coordinated cultural heritage protection of the Henan section of the Sui–Tang Grand Canal.

2.2. Data Sources and Selection

Two types of data are applied in the study: (1) Heritage resource data, including nationally protected cultural relics (Batches 1–8), nationally intangible cultural heritage (ICH), and provincially protected cultural relics (Batches 1–8), which were sourced from the National Cultural Heritage Administration and the Henan Provincial Cultural Relics Bureau. (2) Geospatial datasets, including the 30 m resolution Digital Elevation Model (DEM) from the Geospatial Data Cloud; the road data from the Open Street Map; and the land use type data from the Resource Environment Science Data Center platform of the Chinese Academy of Sciences.

The heritage data were screened based on spatio-temporal and functional correlations with the canal, according to the following explicit criteria:

(1)

Temporal Scope: The study focused on heritage from the Sui–Tang Dynasties to the late Qing period (581–1911 CE), while also incorporating pre-Qin era heritage that underwent significant functional evolution or development due to later canal transportation, as supported by archeological and historical–geographical evidence. For example, the Songgu Gucheng (Song State Ancient City) and Qifeng Gucheng (Qifeng Ancient City) were included. The Songgu Gucheng [37], a World Cultural Heritage site along the Tongji Canal section, demonstrates how the canal sustained urban continuity through its riverbanks, canal remnants, and the archeological phenomenon of “stacked cities” in Shangqiu. The Qifeng Gucheng, originally built as a military stronghold along the Honggou water system in the Spring and Autumn Period, later had its administrative functions relocated to Bianzhou during the Tang Dynasty due to the eastward shift in canal transport hubs, reflecting the canal’s role in reshaping pre-Qin heritage spatial functions. Both sites were, therefore, included.

(2)

Functional Relevance: Emphasis was placed on core carriers of the canal system, such as water transport governance, hydraulic engineering, and commercial hubs. For heritage sites with debated functions, a validation panel comprising ten experts—four archeologists, four historical geographers, and two heritage conservation scientists—was established. A two-round Delphi method was applied: in the first round, the experts independently rated the functional relevance of each heritage site to the canal on a 1–5 scale; in the second round, cases with significant discrepancies were discussed until consensus was achieved. Throughout this process, 15 disputed heritage sites were reviewed, 3 of which were excluded due to a consensus level below 80%, resulting in an inclusion-to-exclusion ratio of 4:1. Additionally, modern replica structures built after 1949 that lack historical authenticity were explicitly excluded.

Ultimately, 252 heritage sites with canal associations were identified. Temporally, the distribution highlights the Sui–Tang (23.0%), Song-Yuan (19.2%), and Ming–Qing (20.8%) periods, which align closely with the historical zenith of the Henan section of the Sui–Tang Grand Canal (

Table 2. Number of heritage sites by historical period along the Grand Canal Heritage Corridor.

Period	Heritage Sites	Count	Percentage
Pre-Qin	Song State Ancient City, Wei State Ancient City, Qifeng Ancient City, Zhecheng Ancient City, etc.	26	8.2%
Han-Wei and Northern–Southern Dynasties	Liyang Ancient City, Shanyang Ancient City, Han-Wei Luoyang Ancient City, Zhoucheng Site, etc.	26	8.2%
Sui–Tang	Sui–Tang Luoyang City Site, Huiluo Granary Site, No. 160 Granary-Cellar Site of Hanjia Granary, Liyang Granary Site, etc.	73	23.0%
Song-Yuan	Northern Song Dongjing City Site, Daxiangguo Temple, Zhouqiao Site, Dangyangyu Kiln Site, etc.	61	19.2%
Ming–Qing	Zhuxian Town, Daokou Town, Suizhou Ancient City, Xun County, etc.	66	20.8%

).

2.3. Research Methods

The corridor construction comprised four sequential phases (Figure 2): (1) Spatial distribution patterns of the heritage sites were identified through GIS-based kernel density estimation (KDE) [38], and heritage value hierarchies were quantified statistically by the analytic hierarchy process (AHP) [39]. (2) To establish a comprehensive resistance indicator system, resistance factors were identified as elevation, slope, traffic accessibility, and land use types which the first two were natural–environmental and the latter two were socio-economic indicators. Factor weights were determined via Geodetector analysis [40]. (3) Single-factor resistance surfaces were extracted through GIS reclassification, and composite resistance surfaces were generated through weighted superposition. Potential corridors were simulated by coupling the MCR model [41] with suitability analysis [42] through GIS cost connectivity tools, and were further optimized by manual grade adjustment. (4) Finally, control width was delineated based on nearest-neighbor analysis between the heritage sites and the canal, and the corridor subsection was divided.

2.3.1. Kernel Density Analysis

Kernel density estimation (KDE) was employed to analyze spatial clustering patterns of the heritage sites along the Henan Section of the Sui–Tang Grand Canal. Spatial density was calculated using the KDE tool in ArcGIS 10.8 [43]. The KDE formula is expressed as follows:

$$f_{n\left(x\right)}={\displaystyle \frac{1}{nh}}\sum _{i=1}^n k\left({\displaystyle \frac{x-x_i}{h}}\right)$$

(1)

Specifically, x_i denotes the geographic coordinates of point i (i = 1, 2,…, n); h represents the bandwidth of the kernel density function, which was calculated using Silverman’s Rule of Thumb—a standard method integrated within ArcGIS Pro’s kernel density analysis tool. This method automatically optimizes the bandwidth value based on the spatial distribution characteristics of the input data, thereby avoiding subjective bias and ensuring the reproducibility and robustness of the results. The term (x − x_i) denotes the distance from the estimated point to the sample point.

2.3.2. Analytic Hierarchy Process (AHP)

The analytic hierarchy process (AHP), developed by American operations researcher Thomas L. Saaty in the 1970s, is a method for decomposing decision-making elements into three layers according to objective, criterion, and alternative. The Expert Scoring Method was used to determine hierarchical weights [44] and measurement scores for each indicator. The formula is expressed as follows:

$$F = \sum _{i=1}^N D_i{X}_{\left\{ij\right\}}$$

(2)

where F is the final score of the heritage; X_ij is the initial data; D_i is the factor weight; and N is the number of evaluation factors. In this study, the hierarchical analysis method was used to evaluate scores of each indicator of the heritage resources, and subsequently to classify the value of heritage resources.

2.3.3. Geodetector

It is a method used to quantify geographic drivers by spatial heterogeneity analysis [45]. The toolbox comprises four analytical modules: factor detection, interaction detection, risk detection, and ecological detection. This study uses the first module to identify the influence of different environmental factors (i.e., resistance factors) on the spatial distribution of heritage in order to scientifically calculate the weight value of each resistance factor in the construction of connecting routes. The weight value is calculated by the following formula:

$$q = 1 -{\displaystyle \frac{1}{N{\sigma }^2}}\sum _{i=1}^n N_i{\sigma }_i^2$$

(3)

where q ∈ [0, 1], with higher values indicating stronger factor influence on the spatial distribution of heritage.

2.3.4. Suitability Analysis

This method is widely applied in landscape ecology studies [46]. It conceptualizes corridor formation as a spatial process that expands from heritage sources across a landscape of varying resistance. The suitability for corridors is determined by the cumulative resistance to be overcome. In this study, the heritage sites in the canal heritage network are spatially connected through cultural routes, which is structurally homologous to the “source–corridor–substrate” system in the ecological network. The formation of the canal corridors is subject to the dual resistances of physiographic setting and cultural diffusion; it is dynamically similar to the process of ecological diffusion. This structural and dynamic congruence justifies the adaptation of ecological suitability frameworks for analyzing cultural heritage spatial configurations.

2.3.5. Minimum Cumulative Resistance Model (MCR)

The minimum cumulative resistance (MCR) model is a graph-theoretic approach that quantifies the “cost resistance” of moving from a source to a target [47]. In the following formula, f represents the positive correlation between the cumulative resistance and the movement process; D_ij denotes the spatial distance from source j to environmental unit i; R_i is the resistance coefficient of environmental unit i to the motion process; and ∑ denotes the total resistance to be overcome during the movement process.

$$MCR=f_{min}\sum _{i=m}^n(D_{ij}\times R_i)$$

(4)

The model simulated the process of experiencing and perceiving the cultural heritage along certain paths and places. The larger the resistance value of MCR, the less suitable the activity is, and the lower the suitability of corridor construction is; on the contrary, the suitability of the area with a small resistance is also higher, which means it is suitable for the establishment of corridors. Based on the above analysis, this study applies the MCR model to generate resistance surfaces and simulate potential heritage corridors with the GIS cost connectivity tool, regarding the heritage sites as the “source”, and then it combines professional knowledge with the real situation to optimize the grading of corridors.

3. Results

3.1. Identification of “Sources”: Multidimensional Evaluation of the Heritage

3.1.1. Classification of Heritage Functional Types

According to the screening criteria in the previous section, the heritage sites are divided into three categories (Figure 3): canal hydraulic heritage [48], canal settlement heritage [49], and canal-related heritage [50]. Canal hydraulic heritage (34 sites, 13.5%) serves as the core infrastructure for water transport. Among them, water conservancy management facilities (e.g., sluices and canals) constitute the largest category, followed by bridges, dams, and transport facilities. Notably, this category includes national granary sites such as Hanjiacang, reflecting Henan’s historical role as the “granary supplying half the empire’s grain” during the Sui–Tang Dynasties. Canal settlement heritage (54 sites, 21.4%) is dominated by historic cities (e.g., Xunxian Ancient City) and commercial townships like Zhuxian Town, which formed the socio-economic nodes along with the canal. Other canal-related heritage (164 sites, 65.1%) is primarily composed of folk culture and religious propagation. The intangible cultural heritage, such as the boatmen’s horn and the Baiquan medicinal meeting, reflects the in-depth influence of the canal on the local social life, and the derivative industry is dominated by the nine kiln sites, such as the kiln at Dangyangyu, showing the pattern of the canal industry belt of “northern porcelain and southern transport”.

3.1.2. Evaluation of Heritage Value

The evaluation system was established based on the actual characteristics of the Henan section of the Sui–Tang Grand Canal. A panel of 15 experts specializing in cultural heritage conservation, archeology, history of hydraulic engineering, and historical geography was invited for questionnaire consultation. The experts primarily consisted of senior researchers and scholars with over ten years of practical experience in Grand Canal conservation management, and those with extensive research experience specific to Henan Province. All the participating experts were informed of the study’s objectives and confirmed no conflicts of interest.

Two rounds of questionnaires were administered: the first round aimed to identify indicators, and the second to determine weights. The evaluation indicators of heritage value were categorized into goal level A, criterion level B, and alternative level C. The selected indicators were further assessed for their relative importance to establish the hierarchical structure. A pairwise comparison matrix [51] was formulated using Saaty’s 1–9 scaling method to quantify the relative weights among criteria. In this scale, 1 denotes “equally important”, 3 “moderately more important”, 5 “strongly more important”, 7 “very strongly more important”, and 9 “extremely more important”. The weights were computed using the Yaahp 10.1 software, and the consistency of each judgment matrix was verified, with all the consistency ratios (CR) being below 0.1, satisfying the consistency requirement. To further assess the statistical reliability of expert consensus, the coefficient of variation (CV) was calculated for indicators at each level. All the weighted indicators exhibited CV values below 0.3, with core criterion-level indicators such as B1 (Heritage Ontology Value), B2 (Association Intensity with Canal System), and B3 (Protection and Utilization Conditions) having CV values of 0.08, 0.12, and 0.22, respectively. These results indicate strong convergence of expert opinions and reliability of the evaluation outcomes.

The hierarchical weighting of the heritage resources in the Henan section of the Sui–Tang Grand Canal was ultimately derived (

Table 3. Heritage evaluation indicator system.

Goal Level	Criteria Level	Weight	Alternative Level	Weight	Performance Metrics
Heritage resource evaluation system of Sui–Tang Grand Canal’s Henan Section A	Heritage ontology value B1	0.587	Historical authenticity C1	0.236	Overlap degree with canal’s active period
					Integrity of original functions
			Technical Representativeness C2	0.187	Embodiment degree of canal engineering techniques
			Carrying a degree of social memory C3	0.164	Carrier of significant historical events
					Attachment intensity of folk legends
	Association intensity with canal system B2	0.309	Direct functional association C4	0.160	Grain transport management facilities
					Navigation service facilities
					Water management facilities
			Derivative functional association C5	0.096	Commercial service architecture
					Religious ritual sites
					Industrial supporting relics
			Spatial dependency association C6	0.053	Linear distance to canal mainstream
					Location on historical transport network nodes
	Protection and utilization conditions B3	0.104	Current conservation status C7	0.076	Preservation degree of historical layout
					Environmental harmony degree
			Service facility conditions C8	0.028	External transportation accessibility
					Public service configuration
					Operational management

). The comprehensive scores of the heritage sites along this section, calculated using the AHP method described in Section 3.1.2, ranged from 2.56 to 9.84. Using the natural breaks method (Jenks) in ArcGIS, the heritage sites were classified into three distinct grades: grade 1 (comprehensive score > 7.23), grade 2 (comprehensive score > 5.65), and grade 3 (comprehensive score < 5.65).

3.1.3. Spatial Distribution Characteristic

Spatial coordinates were georeferenced by using Baidu Maps’ latitude/longitude tool and historically corrected through the archeological literature. A spatio-temporal database for the Sui–Tang Grand Canal’s Henan section was subsequently constructed, integrating attributes such as chronology, functional classification, levels of value, and geolocation (Figure 4).

To objectively reflect the spatial distribution patterns of the different heritage categories, kernel density estimation was applied, in which the bandwidth (h-value) was automatically optimized based on the spatial characteristics of the data itself (

Table 4. Optimal bandwidth of heritage categories.

Heritage Category		Optimal Bandwidth (Meter)	Approximate (km)
Functional Type	Canal Hydraulic Heritage	47,460.74	47.5
	Canal Settlement Heritage	26,183.26	26.2
	Other Canal-Related Heritage	33,782.31	33.8
Value Grade	Grade 1 Heritage Sites	43,072.61	43.1
	Grade 2 Heritage Sites	39,782.67	39.8
	Grade 3 Heritage Sites	27,962.10	28
Overall	Total Heritage	26,875.39	26.9

), ensuring the scientific validity and comparability of the density estimation results. Subsequent analyses were conducted based on this set of optimized bandwidth parameters.

• Spatial distribution of heritage by type

The spatial distribution of the three major types of heritage, including canal hydraulic heritage, canal settlement heritage, and other canal-related heritage (Figure 5a–c), showed obvious functional differentiation through kernel density analyses: The canal hydraulic heritage formed a high-density agglomeration area with Luoyang, Kaifeng, and Hebi as the cores, which are highly coincident with the historical waterway hubs, reflecting the anchoring effect of water conservancy engineering facilities such as locks and dams and embankments in ancient times [52]. The canal settlement heritage extended linearly along the Tongji Canal and the Yongji Canal, and formed a high-density axis of “Zhengzhou–Kaifeng–Luoyang”, which confirmed the historical canal camping system of “one shop for ten miles and one post for thirty miles”, and embodied the commerce and trade effect spawned by the canal transport [53]. Other canal-related heritage spread in patches with Luoyang and Zhengzhou as the twin nuclei, reflecting the spatial coupling between the spread of intangible heritage and regional cultural centers [54]. This differentiation had further given rise to function combination-based zoning: single-function types (e.g., Shangqiu waterworks remains and Yiyang settlement remains) were mostly distributed in the fringe area, while composite function types (e.g., waterworks–settlements and settlements–industries) were concentrated in the core area. For example, the Luoyang Huanjia Cang and the Sui and Tang Dynasty capital city constituted the “Cangcheng symbiosis” mode, and the Kaifeng–Zhouqiao Site and the Bianhe Street formed the “water industry–commerce” composite carrier.

2.

Spatial distribution of heritage by grade

The result of the kernel density analysis of the heritage sites at different levels (Figure 5d–f) showed the following: Grade 1 heritage sites were concentrated in the canal governance centers, such as Luoyang and Hebi, which strengthened the spatial anchorage through the dual attribute of “canal node + administrative center”. Grade 2 heritage sites formed a secondary dense zone along the main canal; for example, Kaifeng Prefecture Bridge Site became the epitome of canal governance in the Northern Song Dynasty due to its direct functional association with the canal, and Jiaozuo Dangyangyu Kiln served as the industrial node of “northern porcelain and southern transport” with a significant derivative functional association but limited protection conditions. Grade 3 heritage sites were distributed in Zhengzhou and Shangqiu as “high density and low value”, such as the Ming and Qing Dynasty Guild Halls in Zhengzhou with a weak spatial dependence on the canal; they were large in quantity but predominantly low-grade in value.

3.

Overall spatial distribution

Through a comprehensive kernel density analysis of all the heritage sites (Figure 5g), the spatial distribution showed “small aggregation, large dispersion”, and presented a three-level circle structure of “core–secondary–periphery”: the core clusters (in Zhengzhou, Luoyang, and Kaifeng) showed a double superposition of strong functional links and high value levels, such as a core hub formed in Luoyang due to the presence of the Hanjiacang and the Sui and Tang Dynasties’ capital cities. The secondary clusters (in Jiaozuo, Xinxiang, and the other 4 municipalities) were characterized by unidimensional types or grades, such as the kiln cluster in the Dangyangyu of Jiaozuo, etc. The peripheral clusters (in marginal countryside areas) were characterized by mostly low-functional associations and low-value grades, such as the guildhalls’ architectural buildings delinked from the Sui and Tang great canal system; the current protection efforts lacked a systematic framework.

This spatial distribution was driven by historical and geographical forces: (1) Historical dynamics: Imperial waterway demands [55] during the Sui–Tang period shaped core zones into hydraulic–settlement complexes, while Song-Yuan commercial expansion fostered “hydraulic–commerce” symbiosis in Kaifeng. Canal fragmentation during the Ming and Qing Dynasties precipitated functional simplification in peripheral regions. (2) Geographical constraints: Most of the heritage sites in the core area were located within 5 km of the Physical Canal System, demonstrating the river-dependent siting logic. The edge area was spatially fractured due to the diversion of the yellow floods or the upliftment of the terrain.

4.

Summary

Taken together, the overall spatial pattern of the heritage emerged through the interplay of functional substratum differentiation and hierarchical modulation mechanisms. (1) Functional substratum: The engineering anchoring of hydraulic heritage, the spatial continuity of settlement heritage, and the cultural diffusion of related heritage shaped the core, linear, and patchy spatial bases, respectively. (2) Hierarchical modulation: The “locked-layer accumulation effect” of grade I heritage strengthened the agglomeration of the core area, while the “edge decay effect” of grade 3 heritage intensified the dispersion of the peripheral area. (3) Compound superposition: If the advantages of types and grades were superimposed in the same direction (e.g., “hydro-engineering + grade 1”), spatial reinforcement would be generated, and a global characteristic of “small aggregation” would be formed. Conversely (e.g., “related heritage + grade 3”), the outcome was functional weakening, manifesting as a global feature of “large dispersion”.

3.2. “Least-Cost Pathway” Simulation: Heritage Corridor Construction

3.2.1. Construction of Resistance Index System

• Resistance factor selection and resistance value determination

The minimum cumulative resistance (MCR) model, originating from land suitability evaluation theory, aims to simulate the evolution of spatial patterns by quantifying the degree to which spatial units impede specific processes or element flows. In the context of cultural heritage corridor construction, the model must account for the combined effects of natural geographical foundations, historical and cultural diffusion patterns, and contemporary socio-economic activities.

To establish an objective and reliable resistance factor system, this study conducted a comprehensive review of the key literature from the past five years in the fields of heritage corridors, cultural geography, and ecological security patterns (see

Table 5. Frequency of resistance factors used in heritage corridor studies.

Reference	Elevation	Slope	Land Use Type	Road Proximity	Other Factors
[56]	✓	✓		✓	Aspect, Distance to Water Systems
[57]		✓			Aspect, Vegetation Coverage, Distance to Water Systems
[58]		✓	✓	✓	Aspect
[18]	✓	✓	✓	✓	Distance to Water Systems
[59]	✓	✓	✓		GDP Density, Ethnic Minority Population Density
[19]	✓	✓	✓	✓
[60]	✓	✓	✓	✓	Slope Aspect, Distance to Central Cities, Distance to Water Systems
[23]	✓			✓	Population Density, Distance to Water Systems

Note: ✓ indicates that the resistance factor was considered in the corresponding study.

). Based on eight studies highly relevant to canal-type linear cultural heritage, frequently adopted factors with an occurrence frequency exceeding 50% were extracted. The results indicated that elevation, slope, land use type, and road proximity are widely recognized core resistance factors in heritage spatial distribution modeling. These factors effectively characterize the formation and preservation environment of heritage along the Henan section of the Sui–Tang Grand Canal in terms of topographic constraints, ecological baseline, landscape pattern, and human activity interference. It is worth noting that the frequently cited factor “distance to water systems” was excluded in this study after careful consideration. The exclusion is based on a fundamental shift in modeling perspective from a “canal-centric buffer” to a “site-oriented connectivity” approach. The core objective of our MCR model is to simulate the least-cost paths for connecting the 252 discrete heritage sites (the “sources”), rather than delineating a zone of influence around the canal line itself. The exclusion is essential to avoid circular logic and methodological bias. Since heritage distribution is inherently correlated with the canal, incorporating “distance to water systems” would strongly bias the model to simply trace the waterway. This would predetermine the results, forcing the corridors to cling to the canal irrespective of the actual resistances—such as topography and land use—between the heritage sites. Such an outcome would contradict our goal of objectively identifying the most functionally efficient corridors based on genuine connectivity costs. Other factors, such as population density, GDP, and POI density, reflect modern socio-economic distributions and are temporally and spatially misaligned with the formation mechanisms of historical heritage. To avoid introducing irrelevant interference, these factors were also excluded from the model. Consequently, the factors of elevation, slope, land use type, and road proximity were selected as the four primary evaluation indicators. These factors effectively characterize the formation and preservation environment of heritage along the Henan section of the Sui–Tang Grand Canal in terms of topographic constraints, ecological baseline, landscape pattern, and human activity interference. Most importantly, they directly capture the genuine costs of connectivity, allowing optimal corridors to emerge objectively from the interaction between the heritage nodes and the landscape matrix.

For the four selected resistance factors, the classification system and corresponding resistance values were determined by comprehensively referencing national technical standards, the existing research results, and the regional natural–environmental characteristics of the Henan section of the Sui–Tang Grand Canal (

Table 6. Resistance factor grading system.

Element	Resistance Grading Classification	Resistance Value	Element	Resistance Grading Classification	Resistance Value	Element	Resistance Grading Classification	Resistance Value
Elevation (m)	14–40	5	Slope (°)	1–3	5	Land use type	Woodland	50
	41–60	10		3–5	10		Grassland	100
	61–80	15		5–8	15		Water	200
	81–120	20		8–15	20		Unused Land	300
	121–240	30		15–20	30		Cropland	400
	241–480	50		20–25	50		Construction Land	500
	481–800	100		25–35	100	Road (km)	<5	5
	801–1000	300		35–50	300		5–10	50
	1001–1200	400		50–76	400		10–20	100
	1200–2174	500		>76	500		20–30	300
							30–40	400
							>40	500

): (1) Elevation data were derived from the DEM elevation model provided by the Geospatial Data Cloud. The classification and assignment were primarily based on fundamental geographical principles: higher elevations generally correspond to greater topographic relief, which significantly impedes the convenience of human activities and the spatial distribution of heritage sites. Therefore, resistance values increase accordingly with elevation. (2) Slope classification criteria mainly refer to the Technical Code for Comprehensive Management of Soil and Water Conservation Planning (GB/T 15772-2008). Steeper slopes impose greater restrictions on transportation, engineering construction, and heritage-related activities. Hence, resistance values escalate with increasing slope grades [61]. (3) The classification system and resistance value assignment for land use types were primarily based on the research findings from Zhou Jing et al., considering the suitability of various land spaces for heritage conservation and corridor construction. Among these, forest land, with its intact natural foundation, is regarded as the most suitable carrier and thus assigned the lowest resistance value. Grassland, with its open space, has relatively low resistance. Water bodies, despite their high ecological value, pose moderate resistance due to poor traversability. Unused land, though less disturbed by human activities, has limited usability and is assigned medium-high resistance. Cultivated land, subject to ongoing agricultural disturbances, receives high resistance. Construction land, characterized by the highest intensity of human activity and significant conflict with conservation objectives, is difficult to transform into heritage protection areas and is, therefore, assigned the highest resistance value. (4) The resistance values for road proximity were established based on methodologies commonly used in ecological security pattern studies by researchers such as Zhu Zhongfei, Li Junhan, and Ye Yuyao. Specifically, a greater distance from roads increases the difficulty of visitor access, resulting in higher resistance values. The detailed classification and assigned resistance values for each factor are presented in the table below.

2.

Weight value determination

Factor weights were quantified using the differentiation and factor detection modules of Geodetector (

Table 7. Divergence and factor detection status.

Factor	X1 (Elevation)	X2 (Slope)	X3 (Land Use Type)	X4 (Road)
q statistic	0.396649	0.139768	0.132936	0.264845
p value	0	0.041165	0	0

) [62]. The explanatory power (q-values) of the predictors was ranked as follows: X1 (Elevation): 0.397 > X4 (Road Proximity): 0.265 > X2 (Slope): 0.140 > X3 (Land Use Type): 0.133. Among these, three factors—X1, X3, and X4—exerted statistically highly significant influences on the spatial distribution of cultural heritage (p < 0.01), while X2 (Slope) also showed a significant influence at the p < 0.05 level.

Further analysis revealed that the elevation factor had the highest q-value, indicating its strongest influence on the spatial distribution of the canal heritage sites—a finding directly linked to the wisdom of ancient canal hydraulic engineering [63]. During the Sui and Tang Dynasties, water flow regulation was achieved through precise control of channel elevation, as documented in works such as the Tang Huiyao Canal Transportation, which noted, “凡漕河所经, 必度高卑” (all canal routes must balance elevation gradients). The road proximity factor ranked second in explanatory power. As modern roads such as the Longhai Railway and Lianhuo Expressway were constructed along the remnants of the ancient canal, the distribution of the heritage sites showed strong overlap with contemporary road networks. The influence of slope was relatively weak, owing to ancient engineers’ use of techniques like “segmental embankment construction” (e.g., in the Zhengzhou–Shangqiu section) to control the canal gradient within 3°, thereby mitigating topographical constraints. Although land use type (X3) also demonstrated a highly significant statistical relationship (p < 0.01), its relatively low q-value may be attributed to the relatively homogeneous distribution of land use types within the study area—particularly the dominance of cultivated land, which formed a structurally uniform landscape matrix that statistically weakened the discriminative power of this factor. Moreover, contemporary land use data, being “short-term data”, may capture residual structural features from historical processes but fail to fully quantify deep historical and cultural layering effects.

After normalizing the q-values, the final weight values for each factor were determined as follows: elevation: 0.41, road proximity: 0.27, land use type: 0.13, and slope: 0.14.

3.2.2. Resistance Surface Generation and Suitability Analysis

• Resistance surface generation

Based on the factor attributes of elevation, slope, land use type, and road, simulating the resistance cost spent to reach the nearest distance heritage source was the core step of constructing the heritage corridor. Firstly, using the reclassification tool of ArcGIS, the elevation resistance surface, slope resistance surface, land use type resistance surface, and road resistance surface at all levels were obtained (in the process of generating the road resistance surface, the Euclidean distance is used for calculation and assigned a value of 0.25 for weighted superposition, respectively) (Figure 6a–h). Secondly, a weighted overlay analysis was conducted by using factor-specific weights, and the integrated resistance surface (comprehensive cost grid) for the Sui–Tang Grand Canal’s Henan section was produced. The resultant resistance values ranged from 4.9 (minimum) to 348.02 (maximum) (Figure 6i).

2.

Suitability analysis

According to the results of resistance surface construction, the study area can be further divided into five zones based on suitability levels: highly suitable area, medium-high suitable area, medium suitable area, low suitable area, and unsuitable area through the ArcGIS Reclassify Tool and Jenks’ Natural Breaks Classification (optimal data clustering) method (Figure 7a). In general, due to the influence of topographic factors such as elevation and slope, suitability zones of the cultural space of the Henan section of the Sui–Tang Grand Canal were distributed in groups. Specifically, high suitability zones were mainly concentrated in Zhengzhou City, Luoyang East, and Kaifeng, where the terrain was flat, and the built-up areas were concentrated. And there was a rich traffic network connecting the surrounding areas and a high degree of connectivity among the heritage sites, so the cost of carrying out the heritage recreation activities was minimal. The overall suitability of the western part of the area was lower due to the topography. In addition, there was a typical linear orientation aligned with major transportation routes (e.g., Longhai Railway) in the high suitability zones, which formed the structural backbone of potential heritage corridors.

3.2.3. Corridor Simulation and Classification

The potential heritage corridors were generated by inputting the heritage “source” (i.e., the above heritage points) and the cost resistance raster data (i.e., the above integrated resistance surface) with the MCR model and GIS cost connectivity tools (Figure 7b). The simulated corridors exhibited a polycentric open-network structure, which was determined by the alignment of transportation corridors. Topographic and geomorphological constraints limited corridor extensibility in specific sectors. A complex, interconnected spatial network formed by numerous heritage sites emerged in the south-central region.

Potential corridors were manually selected and optimized based on the cultural value of the linked heritage sites, along with the actual transport network in the region, the layout of the river and water system, and the existing linear cultural heritage. The primary corridor should connect high-level heritage sites and cover fewer highly obstructive high-speed and railway facilities to ensure the connectivity of the route; the secondary corridor should connect all heritage sites as far as possible to ensure the integrity of the route. Through a series of optimization choices, a hierarchical corridor system for the Henan section of the Sui–Tang Grand Canal was finally formed and classified into two functionally stratified tiers (Figure 7c). The primary corridor consists of four routes, taking Zhengzhou as the core to extend to the north, west, and east, connecting the first-/second-level heritage sites, with better ecological and cultural attributes, reflecting the essence of canal culture. Secondary corridor takes primary heritage corridors as the axis to extend on both sides, connecting the third-level heritage nodes, showing the diversity of canal culture.

3.2.4. Corridor Transverse Zoning

The spatial extension scale along the heritage corridor directly affected the effectiveness of the systematic protection of the cultural heritage in the Henan section of the Sui–Tang Grand Canal. Referring to the existing studies [64], the spatial proximity relationship between the heritage sites and corridors derived through the Nearest Neighbor Analysis tool in ArcGIS was taken as an important basis for spatial zoning of the heritage corridors.

This study focused on the spatial zoning along the primary corridor. The result of Nearest Neighbor Analysis showed that if the corridor width was within 10 km, 72.62% of the heritage sites (183 sites) would be covered, and if it was within 25 km, 91.67% of the heritage sites (231 sites) would be covered. Therefore, the study conducted buffer analyses with a radius of 10 km and 25 km, respectively (Figure 7d). According to the spatial relationship between the heritage sites and corridors, the influence area of the corridor was further divided as follows: (1) Core area (0–10 km): Covering more than 80% of the heritage resources, which focused on the core values of Waterway Grain Shipping, water conservancy projects, etc. (2) Buffer area (10–25 km): Covering 19.05% of the heritage sites, which was connected by a local linear heritage trail network. (3) Radiation area (>25 km): As a cultural radiation transition zone, containing a few scattered heritage sites.

Finally, it was determined that the suitable width of the heritage corridor of the Henan section of the Sui–Tang Grand Canal should be 25–30 km, which covered 91.67–95.02% of the heritage points, with a total size of the primary corridors about 28,500 km².

3.2.5. Corridor Longitudinal Section

The canal culture exhibits holistic characteristics and also demonstrates spatial differentiation due to varying geographical locations and developmental stages among its sections. Based on the heritage value and corridor characteristics, along with the principles of continuity and integration, we integrated the heritage corridor of the Henan section of the Sui–Tang Grand Canal into four longitudinal subsections (Figure 8). Each subsection features a dual-layer system: a core area (10 km on either side of the corridor) and a buffer area (25 km on either side of the corridor). See

Table 8. Heritage corridor subsection of the Henan Section of the Sui Tang Grand Canal.

Subsection Name	Location	Corridor Length (km)	Transverse Zone	Subsection Area (km2)	Sites Count	Sites Density (Sites/km2)
Luo-Zheng subsection	Western Tongji Canal Section		Core area	2361.81	42	0.0178
		153.17	Buffer area	3669.17	14	0.0038
			Total	6030.98	56	0.0093
Zheng-Jiao subsection	Junction of the Two Canals		Core area	2529.83	39	0.0154
		88.17	Buffer area	2341.13	15	0.0064
			Total	4870.96	54	0.0111
Bian-Shang subsection	Eastern Tongji Canal Section		Core area	3944.85	32	0.0081
		232.88	Buffer area	6343.38	9	0.0014
			Total	10,288.23	41	0.0040
Jiao-An subsection	Yongji Canal Section		Core area	3224.75	34	0.0105
		224.41	Buffer area	4919.70	11	0.0022
			Total	8144.45	45	0.0055

for details of this structure.

The Luo-Zheng subsection is located in the western part of the Tongji Canal, with a primary corridor length of 153.17 km and an area of 6030.98 km². It includes 56 heritage sites with a high density. This subsection mainly includes grade 1 heritage sites such as the Huiluo Granary, Hanjia Granary, and the Sui–Tang Luoyang City Ruin, highlighting the military and governmental warehousing function as the center of the canal. It is the core subsection of the research area. During the Sui and Tang Dynasties, this subsection undertook the grain transport function relying on the main canal line of the Luo River. The warehousing facilities and the administrative colony of the capital city formed the layout of “Cangcheng as a whole”, which demonstrates the systematic development of the military and political functions of the canals under the centralized system.

The Bian-Shang subsection is located in the eastern part of the Tongji Canal, with a primary corridor length of 232.88 km and an area of 10,288.23 km², including 41 heritage sites with the lowest heritage density. This subsection mainly includes grade 2 and grade 3, such as the ruins of the Northern Song Dynasty’s Dongjing City, Zhu Xian Town, and the ancient city of Suizhou. It demonstrates the spatial coupling between canal transport and commercial towns, which is the core subsection of the study area. After Bianliang was designated as the Northern Song capital, the canal function shifted mainly from military transport to commercial circulation. The “river–city symbiosis” pattern based on Zhouqiao and Bianhe Street proved the driving effect of canal economy on the commercial transformation of the capital city [65]. Meanwhile, the rise of Zhuxianzhen and other towns during the Ming and Qing Dynasties continued the spatial genes of the canal wharf economy.

The Jiao-An subsection is located in the northern part of the Yongji Canal in Henan Province, with a primary corridor length of 224.41 km and an area of 8144.45 km², including 45 heritage sites. This subsection is mainly represented by heritage sites such as the Liyang Granary, Daokou Town, and Weiyuan Temple. It demonstrated the development of canal towns and diverse cultures, which is an important subsection of the study area. During the Sui and Tang Dynasties, facilities such as the Liyang Granary established the canal’s status as the lifeline of the national canal transport system. During the Ming and Qing Dynasties, the development of regional transportation and commerce spurred the emergence of the prosperity of commercial towns like Daokou Ancient Town. Furthermore, it fostered diverse cultural landscapes, including merchant guild halls and folk beliefs, reflecting the synergistic evolution of canal management, commercial trade, and cultural development [49].

The Zheng-Jiao subsection is located at the junction of the Yongji Canal and the Tongji Canal, with a primary corridor length of 88.17 km and an area of 6030.98 km², including 54 heritage sites with the highest heritage density. It is the connecting subsection of the study area. Since the Tang Dynasty, it has been a transitional zone connecting the northern and southern waterways within Henan Province. During the Song Dynasty, the iron smelting industry drove the expansion of industrial and commercial settlements. This expansion established a multifunctional corridor section that connected water transport to land transport.

3.3. Exploration of Protection Strategy Based on Heritage Corridor System

According to the abovementioned research, a three-tier protection system encompassing “heritage cluster–corridor entirety–corridor transverse zoning and longitudinal section” was established, and conservation strategies were further explored.

3.3.1. Heritage Clusters: Hierarchical Management and Thematic Revitalization

Based on the spatial distribution characteristics of the heritages revealed by the kernel density analysis, it is found that the heritage along the Henan section of the Sui–Tang Grand Canal has formed a tripartite clustered hierarchy consisting of core, secondary, and peripheral, with differentiated strategies proposed for their resource endowment and conservation needs.

• Core heritage clusters: strict protection and restoration

The kernel density analysis shows that the core heritage clusters are distributed in Luoyang, Zhengzhou, and Kaifeng, represented by Hanjia Cang and Huiluo Cang. These heritage clusters represent the canal’s hydraulic engineering technology and transportation function. In the process of protection and inheritance, the first priority is to ensure the integrity of heritage, and for heritage requiring restoration, it is essential to ensure that the restoration process adheres to the principle of authenticity. In addition, it is also necessary to strengthen the community coordination [66] and provide subsidies to the residents along the canal within a range of 5 km (e.g., in the Chanshui River District of Luoyang and in the Zhuxian Town of Kaifeng). This enables them to participate in heritage’s daily inspections, explanations, and emergency responses, thereby establishing a double guardianship guarantee combining professional teams with local communities, which promotes the transformation of the core heritage clusters from static historical landmarks to dynamic cultural scenarios.

2.

Secondary heritage clusters: functional expansion and moderate development

The secondary heritage clusters are distributed in six sub-collective areas, such as Jiaozuo and Xinxiang, represented by Daokou Ancient Town and Zhuxianzhen Wharf, which are important transition zones connecting the core heritage with the peripheral heritage. In view of their spatial characteristics and resource endowment, it is necessary to achieve a sustainable balance between protection and reuse through functional expansion and moderate development to delineate core areas for intangible cultural heritage (ICH) in places such as the Daokou Ancient Town, where intangible cultural heritage is highly concentrated. In these areas, we should preserve workshops for ironwork, woodblock prints, and traditional dyeing, and strictly limit the proportion of commercialization, so as to avoid the erosion of authenticity by over-tourism, to restore the historical scenes of grain storage and distribution of goods with Zhuxian Town Wharf as the hub, while implementing experience projects such as the canal bazaar and ICH performance. The development of theme lines focuses on the value interpretation of hydraulic heritage, designing the “Hydraulic Science and Technology Study Line” (Huiji Bridge–Hehe Stone Bridge section) to promote the transformation of heritage value into educational resources. Through the dual strategy of restrictive protection and thematic development, the secondary heritage clusters will be transformed from “static preservation” to “dynamic empowerment” on the basis of maintaining authenticity, providing impetus for the synergistic development of regional culture and economy [67].

3.

Marginal heritage clusters: preventive protection and marking reinforcement.

The marginal heritage clusters are scattered in low-density areas such as northwestern Anyang, Puyang, and southwestern Luoyang. These areas are located in the canal branches or mountainous zones where heritage distribution is fragmented and the ecological environment is sensitive, while facing threats from natural weathering and anthropogenic disturbances. Therefore, establishing a real-time monitoring system and installing an intelligent interpretation board is required to implement precise control and intelligent marking in order to enhance protection visibility.

3.3.2. Corridor Entirety: Regional Spatial Integration and Systematic Restoration

It is necessary to take the corridor as the core link connecting heritage sites, so as to systematically integrate the regional space and lay the foundation for the subsequent stratified and segmented protection. Firstly, the corridor spatial skeleton should be constructed to enhance the accessibility and efficiency of the whole region. Secondly, the ecological and functional dimensions should be injected to transform the corridor into a perceptible cultural axis, so as to establish a holistic conservation continuum spanning physical connection to value regeneration, and to drive the adaptive use of the whole region’s heritage.

• Regional spatial integration

The previous section has modeled two levels of corridors: the main corridor extends in three directions with Zhengzhou as the nucleus, linking high-level heritage sites; the secondary corridor extends in both directions with the main line as the axis, linking up all the heritage points. The two corridors have their own focuses in terms of functional positioning, target objects, and development directions, so their conservation strategies should be differentiated in order to realize functional complementarity and regional synergy.

Major heritage corridor: As the core skeleton of the heritage network, it is necessary to focus on the enhancement of the connectivity among heritage sites, and explore strategies to improve the accessibility and effectiveness of corridor construction, starting from the perspectives of roads, slopes, and land use types: In areas where highways/railways intersect with corridors, suitability for heritage activities should be improved by constructing canal-themed tunnels and transforming berms into viewing platforms. In areas with steep slopes, zigzag paths and other gentle slopes should be used to balance the impact of terrain height differences on accessibility. In areas where land use and heritage activities are in conflict, there is a need to promote the regeneration of productive spatial functions, such as planting historical crop varieties on farmland [68], so that it can have both ecological buffers and heritage education functions.

Secondary heritage corridor: As the extension of the major corridor, it should effectively integrate scattered grade 3 heritage sites and ensure comprehensive protection and development opportunities for regional heritage. Therefore, it should pay attention to the insufficient accessibility and landform fragmentation, such as setting up composite stations in remote villages, and constructing feeder trails and adventure trails in the marginal mountainous areas. In addition, the secondary corridors should also leverage their advantages in the transport hubs, tourism feeder routes, and consumer price to assume appropriate roles within the major corridor’s protection framework, ultimately establishing a complementary dual-corridor framework characterized by a “cultural backbone–service network” configuration.

2.

System restoration

On the basis of the two corridor pattern, we explore specific strategies in terms of scale, ecology, and function to transform the spatial skeleton into a cultural–ecological complex system. Firstly, the corridor bandwidth is defined to transform the macro-level layout foundation into actionable regulatory boundaries. Secondly, the ecological shortcomings in the spatial integration should be made up for. Finally, the differentiated positioning of the major and secondary corridors should be reinforced through functional implantation.

Scale control: Based on the near-neighbor analysis, the major corridor width is set at 25–30 km (covering 95% of the heritage sites), and the dynamic adaptability principle should be adopted in its implementation. It is necessary to prioritize preserving the integrity in areas with high heritage density (e.g., Zhengzhou–Kaifeng section), and coordinate the relationship with the manmade facilities, such as the Lianhuo Expressway, the Beijing–Guangzhou Railway. For areas difficult to coordinate, such as the railway junction areas, the spatial continuity of the corridor should be maintained through appropriate widening.

Ecological restoration: We delineate a 50 m core buffer zone within high-density corridor networks, with strict prohibition of hardening works, while enforcing ecological protection in biodiversity hotspots [69]. Vegetation rehabilitation follows the historical authenticity principles and ecological adaptability, prioritizing species documented in the Sui and Tang Dynasties’ archival sources, and concurrently implementing soil–water purification and wind–sand prevention in riparian zones. This multi-tiered restoration framework can reintegrate fragmented heritage sites into palimpsestic landscape matrices, achieving tripartite value symbiosis encompassing heritage protection, biodiversity resilience, and public recreational experience [70].

Functional implantation: It is necessary to implant cultural and recreational functions to transform the linear corridor into a perceivable and participatory cultural experience axis. For example, we can utilize theme-based designs to create differentiated experience scenarios; leverage the major corridor to link Zhengzhou Ancient Bianhe Estuary, Kaifeng–Zhouqiao Ruins, and other heritage sites, and establish immersive scenarios. We also need to design ecological recreational routes in ecologically well-functioning areas, and establish pedestrian pathways and slow-travel along corridor margins, so that the public can experience the canal cultural landscape on foot [71]. Through the cultural expression of ecological scenes, the narrative tension of the canal heritage can be strengthened, thus promoting the transformation of the heritage corridor of the Sui and Tang Grand Canal from a “geographic corridor” to a “cultural–ecological community”.

3.3.3. Corridor Zoning and Section: Transverse Zoning Protection and Longitudinal Section Coordination

• Zoning protection

This study takes the three-tier system of “core area–buffer area–radiation area” as a framework, and balances the needs of heritage protection, ecological restoration, and regional development through differentiated spatial management strategies, so as to carry out the transverse zoning protection of the Henan section of the Sui–Tang Grand Canal.

Core area (0–10 km): Extending 10 km laterally from both sides of the major corridor, encompassing 72.62% of the heritage sites in the study area, most of these sites (e.g., granaries, wharves, and locks and dams) have significant functional relevance to the canal, and are the core carriers of the canal’s canal function and hydrological wisdom. Within the management of core areas, the authenticity principle should be determined, and riverbank hardening, sand mining, and new high-rise buildings are strictly prohibited.

Buffer area (10–25 km): Extending 10–25 km laterally from both sides of the major corridor, encompassing 19.05% of the heritage nodes in the study area, mainly including the post sites, branch line wharves, and farmland and water conservancy facilities. Although these heritages do not directly carry canal function, they are the support system of the canal’s economic network, and have provided critical services for grain transshipment and ship maintenance in history. Within the management of buffer areas, the ecological restoration should be prioritized, and the adaptive use should be limited. In addition, it is necessary to promote the culture–ecology synergy based on the preservation of heritage authenticity: For example, we can construct a canal farming culture park in the dominant area of arable land, and create a demonstration area of heritage agriculture. Through the strategy of low-interference use, the synergistic development area becomes a cultural–ecological buffer connecting the core protection area and the outer radial area. Through the low-disturbance use strategy, the synergistic development area will become a cultural–ecological buffer area connecting the core protection area and the outer radiation area.

Radiation area (25 km): Extending 25 km laterally from both sides of the major corridor, encompassing 8.45% of the heritage nodes in the study area. The heritage sites are relatively dispersed and far away from the major corridor, characterized by fragile ecosystems and marginalization risks. It is necessary to build a preventive protection system through the cross-domain synergy and resilience technology, so as to incorporate the isolated heritage into the overall network, and to provide support for the holistic protection of the Sui–Tang Grand Canal’s Henan section.

2.

Section coordination

Differentiated functional positioning and protection strategies should be developed for the subsections based on their resource endowments and spatial characteristics (

Table 9. Functionality of the four subsections of the heritage corridor.

Name	Role	Location in Canal System	Functional
Luo-Zheng subsection	Core subsection	Western Tongji Canal	Sui–Tang Dynasties’ Water Transport Section: Military and Grain Storage
Bian-Shang subsection	Core subsection	Eastern Tongji Canal	Northern Song Dynasty Water Transport Section: Water Transport Economic Belt
Jiao-An subsection	Important subsection	Yongji Canal	Multi-cultural Heritage
Zheng-Jiao subsection	Connecting subsection	Junction of the Two Canals	Land–Water Transport Hub

).

Luo-Zheng subsection: Located in the western origin of Tongji Canal, it is dominated by the complex heritage of hydraulics–settlements–others, and is designated as the “Canal Origin and Ecological Governance Zone”. Conservation efforts should focus on restoring the storage site group, delineating the core protection area, restricting the high-intensity development, and constructing the “site–water” composite landscape system.

Bian-Shang subsection: Located east of the Tongji Canal, this subsection is dominated by the complex heritage of hydraulic and settlement, carries the symbiotic relationship between canal junction and commercial town, and is designated as the “spatial carrier for the canal economic belt”. It is necessary to restore the axes of the Zhouqiao Site and Bianhe River, and reproduce the pattern of “four waters through the capital” through virtual reality and marker tools. Additionally, there is a need to establish living heritage zones within commercial districts, implement building height restrictions and architectural style guidelines, while preserving traditional merchant guild cultural spaces.

Jiao-An subsection: Located in the northern part of the Yongji Canal, this subsection is dominated by the complex heritage of settlement and other heritage, and is positioned as a “Town Development and Multicultural Heritage Zone”. The visual corridor between the historic city and wharf should be restored, the policy of “repair instead of demolition” should be implemented to preserve the traditional courtyards, and the cultural memory should be revitalized through sacrificial ceremonies exhibition.

Zheng-Jiao subsection: Located at the intersection of Yongji Canal and Tongji Canal, it is dominated by the heritage of settlement and industry, and is designated as the “Craft Production and Intermodal Transport Hub”. Conservation efforts should focus on the layout of heritage interpretation nodes and industrial heritage narratives.

4. Discussion

4.1. Comparison with Existing Studies

This study used the GIS spatial analysis tool to identify the spatial distribution characteristics of heritage sites, which were the basis of corridor construction. In recent years, GIS has been widely used for analyzing cultural heritage distributions. For example, Gao et al. [72] investigated Henan cultural sites spanning the Longshan to Xia-Shang periods, and Ge et al. [73] examined China’s agricultural heritage systems, and both verified the effectiveness of the GIS spatial statistics. This study showed that the heritage distribution in the Sui–Tang Grand Canal’s Henan section was “local agglomeration but global decentralization”, with high-density clusters in core nodal cities along the canal (Luoyang, Zhengzhou, and Kaifeng). It is in line with the work of Jiao et al. [74], which indicated the strong spatial dependency of cluster locations that was substantially influenced by the Grand Canal’s core–periphery radiation effects.

For the heritage corridors simulation, we selected the MCR model. Li et al. [75] and Zhang et al. [76] studied the intangible cultural heritage of the Yellow River Basin and the cultural heritage of Huizhou, which proved the reliability of the MCR model for the heritage corridors construction. In this study, four resistance factors were identified: elevation, slope, land use type, and road infrastructure. Weight determination constitutes a critical component of corridor modeling. The existing research predominantly employed expert scoring [14], analytic hierarchy process (AHP) [77], and entropy methods [78], while this study innovatively integrated geographical detectors to enhance weighting objectivity. The corridors simulated presented a polycentric radiating network and a high-density distribution features in Luoyang and Zhengzhou, where it was conducive to the corridors construction because of their dense heritage sites, flat terrain, and high road accessibility. This was similar to the analysis results of Zhang et al. [76].

After the corridor simulation and classification, this research further established a dual-dimensional spatial partition integrating transverse zoning with longitudinal section. In previous studies, scholars paid more attention to the transverse zoning. For example, Ji et al. [79] used buffer zone analysis to define the corridors’ spatial structure as core area, buffer area, and coordination area. It further included a longitudinal corridor dimension for the purpose of establishing a systematic research framework of heritage corridors and realize synergies between heritage preservation and regional development, which was another innovative point of this study. Finally, it proposed protection strategies of “heritage clusters–holistic corridor–corridor transverse zone and longitudinal section” based on the corridor system, which was systematic and adaptive compared to the protection framework of “heritage site, corridor and zone” in the previous studies. It could effectively address the fragmentation in conserving the Sui–Tang Grand Canal’s Henan section heritage.

4.2. Theoretical Value and Practical Implications of This Study

The “dual-dimensional evaluation–corridor simulation–sectional collaboration” framework proposed in this study offers a methodological integration perspective for research on linear cultural heritage. By cross-disciplinarily incorporating the MCR model from landscape ecology, kernel density analysis from spatial statistics, the Geodetector, and heritage value assessment (AHP) from human geography, it provides an operational analytical process for understanding the formation mechanism of the “point-line-plane” spatial pattern in heritage spatial distribution. This is expected to provide a theoretical reference for the synergistic “cultural–ecological” conservation of transnational linear heritage such as the Silk Road and the Inca Trail.

Based on the research findings, this study explores practical pathways for the construction of the Grand Canal National Cultural Park in the Henan section: At the heritage cluster level, a three-tiered differentiated strategy for “core, secondary, and peripheral” clusters is proposed, implementing distinct measures such as strict restoration, functional adaptation, and smart monitoring to accurately address the conservation needs of each area. At the holistic corridor level, regional spatial integration is achieved by leveraging a dual-level corridor as a spatial link, and the corridor is transformed into a culturally perceptible axis through the three dimensions of scale governance, ecological restoration, and functional implantation. At the corridor section level, based on the functional positioning of the four subsections, differentiated cultural–ecological function implantation strategies are proposed—such as the “water conservancy–farming” thematic study route design in the Shangqiu subsection and the “bridge–granary–town” thematic tour route in the Anyang subsection—to achieve a synergistic effect between heritage conservation and regional development.

4.3. Research Limitations and Future Research Directions

Although this study attempted to construct a systematic analytical framework, several limitations remain: (1) Inherent uncertainties in data and models: First, the weight system of resistance factors constructed in this study relies on heritage site distribution data, which may be influenced by the completeness of historical records, the contingency of archeological excavations, and modern land cover, introducing potential biases in historical data. Moreover, the classification and assignment of resistance factors lack internationally standardized criteria; although this study determined them through case-based calibration and the relevant literature, striving for objectivity, a certain degree of subjectivity was inevitably introduced. Second, while kernel density analysis effectively reveals “hotspots” of heritage aggregation, caution is needed when directly equating its results with historical functional zoning, as high-density areas may result from non-historical factors such as preservation conditions and research focus. Additionally, GIS spatial data inherently contain scale and classification errors, and such uncertainties may accumulate and amplify in the process of generating comprehensive resistance surfaces and corridor boundaries, affecting the accuracy of the results. (2) Integrated application of methodologies: Although the AHP expert consultation method adopted in this study ensured professional assessment, expert judgments are difficult to entirely avoid subjectivity, and potential circular reasoning may exist between expert evaluations and the historical literature interpretation. On the other hand, the application of landscape ecology models in the cultural heritage field requires a deeper exploration of theoretical adaptability. A core issue for future research is how to more accurately align the physical spatial simulation of “resistance” in the model with abstract socio-historical processes such as cultural diffusion and economic linkages.

Based on the above limitations, future research can be deepened in three directions: First, strengthen uncertainty management—for example, by performing sensitivity analyses on key parameters (such as weights and resistance values) to demonstrate the robustness of corridor simulation results under different parameter scenarios, and presenting corridor spatial ranges with “confidence intervals” to enhance the scientific rigor of the outcomes. Second, deepen the quantitative analysis of historical driving mechanisms by integrating methods such as Historical GIS (HGIS) and bibliometrics to more quantitatively reveal how historical processes such as canal transport, population migration, and administrative changes shaped the spatial patterns of heritage, thereby moving beyond describing spatial patterns to explaining their causes. Third, explore the integration of emerging technologies—such as using digital twin technology to build dynamic management platforms, or incorporating new data types like social media POIs and nighttime light data to assess the contemporary vitality of heritage, promoting the evolution of research from static conservation to dynamic sustainable management.

5. Conclusions

This study took the Henan section of the Sui–Tang Grand Canal as the research object, simulated the heritage corridors based on the minimum cumulative resistance model (MCR), proposed a research framework of “heritage clusters–holistic corridor–transverse stratification and longitudinal section”, and systematically answered the key questions posed in the previous section. It should be emphasized that the core value of this framework lies in providing a technical tool for spatial identification and priority zoning, whose effective implementation requires integration with place-based political coordination, community participation, and adaptive management processes. The main conclusions were as follows:

Regarding heritage site evaluation, the following were performed: (1) It systematically analyzed the heritage cultural values and revealed the spatial distribution characteristics. A total of 252 heritage sites were divided into three categories: canal hydraulic heritage (13.5%), settlement heritage (21.4%), and other related heritage (65.1%), which were further divided into 22 subcategories. The overall distribution exhibited a “local clusters within global dispersion” pattern, and formed a three-tiered concentric structure of “core–secondary–edge” zones. (2) Differentiated conservation strategies were proposed for heritage clusters at different levels: Core heritage clusters (e.g., the high-density Luoyang–Zhengzhou–Kaifeng area) should implement integrated “point–axis–area” protection. It is recommended to establish municipal-level cultural heritage conservation special funds, prioritized for site restoration and environmental improvement within core zones, and explore policy instruments such as transfer of development rights to alleviate conflicts between conservation and development. Secondary heritage clusters (e.g., the ancient Daokou town in Jiaozuo and the canal wharf complex in Weihui) should adopt a “thematic development + moderate functional expansion” strategy. This includes establishing traditional craft workshops, restoring historical settings, and strictly controlling the proportion of commercial activities. Peripheral heritage clusters (e.g., scattered sites in northwestern Anyang and Puyang) should implement a “preventive conservation + precision marking” model. Low-intervention ecological slope protection techniques are recommended for preserving canal relics, along with the installation of smart guideposts. For highly dispersed sites, management units may be simplified by adopting a “heritage point record card” system to avoid inefficient cluster-based investment.

Concerning heritage corridor construction, the following took place: (1) It investigated the resistance mechanisms during the construction of heritage corridors through MCR, and found that the interaction of natural and social resistance factors was significant, with the influence was ranked as elevation > road proximity > slope > land use type. Among these factors, the elevation exerted the most significant influence on the heritage distribution, which demonstrated the hydraulic engineering wisdom of adapting to natural topography and constructing segmented embankments in canal development. (2) It revealed heritage corridor characteristics: The holistic corridor was characterized by a polycentric, outwardly radiating open network pattern. The primary corridors interlinked high-tier heritage sites to epitomize the quintessence of canal culture, and the secondary corridors interlinked low-tier heritage sites to exemplify the diversity of canal culture. (3) It proposed an integrated conservation strategy for heritage corridors: using two-tiered corridors as spatial nexuses for regional integration, it transformed them into tangible cultural axes through scale regulation, ecological restoration, and functional programming. (4) At the implementation level, corridor realization requires reconciling institutional and management constraints. Cross-administrative coordination should be achieved by formulating collaborative guidelines to standardize ecological revetments, greenway width, and signage systems. At intersections with high-resistance infrastructure, “node-skipping” designs—such as themed ecological bridges—can be adopted to balance ecological connectivity and cultural imagery. In densely built-up areas, linear parks can be embedded into existing riverside greenways, complemented by legislative controls on building heights. Furthermore, a “resident guardian” system should be promoted in living heritage areas such as Hua County and Xun County, providing ecological compensation to residents within 500 m of the corridor and encouraging their participation in inspection, intangible cultural heritage performances, and cultural interpretation.

On corridor transverse zoning and longitudinal section, the following were conducted: Based on spatial proximity analysis and heritage functional characteristics, this study constructed a spatial planning system characterized by “transverse zoning management and longitudinal sectional coordination”. (1) At the transverse zoning level, the areas on both sides of the primary corridor were divided into three-tiered management zones according to heritage distribution density and ecological sensitivity: the core area (0–10 km), buffer area (10–25 km), and influence area (>25 km), with differentiated protection strategies formulated for each. The core area covers 72.62% of heritage sites, including core functional heritage such as granaries, wharves, and sluice gates, and is subject to the strictest protection. Activities such as riverbank hardening, sand mining, and new high-rise construction are prohibited, emphasizing the authenticity of heritage and the conservation of hydrological environments. The buffer area contains 19.05% of heritage nodes, primarily consisting of branch wharves and farmland water conservancy facilities. Low-intensity ecological and recreational uses are permitted, such as the layout of relay stations and study bases, but architectural styles should be dominated by blue bricks and wood. Ecological restoration and cultural–ecological synergies are promoted—for example, by establishing canal farming culture parks to form a cultural–ecological buffer between the core and influence areas. The influence area includes scattered heritage nodes accounting for 8.45% of the total. Ecological agriculture and cultural creative industries are encouraged, and a preventive protection system is built through cross-sectoral collaboration and resilience technology to integrate isolated heritage into the overall network. (2) At the longitudinal section level, based on heritage type, functional characteristics, and corridor density, the primary corridor was divided into four functional segments: Luo-Zheng, Bian-Shang, Jiao-An, and Zheng-Jiao, with tailored conservation strategies and coordination measures designed for each. The Luo-Zheng segment, dominated by hydraulic–settlement composite heritage, is designated as a core water source and ecological management zone. Efforts focus on restoring reservoir site groups and constructing a “site–water” composite landscape system. A Luoyang–Zhengzhou joint conservation center should be established to coordinate ticketing mechanisms and interpretation standards. The Bian-Shang segment, centered on the composite heritage of hydraulic facilities and settlement sites, should prioritize the restoration of the Zhouqiao Site and the Bian River axis, using virtual reality technology to recreate the historical pattern of “four waters crossing the capital”. A Kaifeng–Shangqiu tourism alliance should be promoted to jointly apply for thematic routes and coordinate the renovation of signage and commercial district facades. The Jiao-An segment, focused on settlement site groups, should emphasize the restoration of visual corridors between the historic urban area and wharves, and protect traditional residences. The Zheng-Jiao segment, primarily composed of industrial and commercial heritage, should emphasize the layout of heritage interpretation nodes.

On the applicability and limitations of the framework the following should be noted: While this framework provides a spatial blueprint for systematic conservation, its applicability has certain boundaries, and future efforts should focus on three areas of refinement: (1) Scale adaptability: At the micro-scale, especially in marginal areas with very low heritage density such as northwestern Anyang and parts of Puyang, strict delineation of “heritage clusters” may not be cost-effective. A management model of “key heritage points–ecological corridors” should be adopted, using smart monitoring facilities at precise heritage points to achieve low-cost, high-efficiency preventive conservation, avoiding over-dispersion of conservation resources. (2) Governance coordination: At the cross-administrative scale (e.g., the Luo-Zheng and Bian-Shang sections), the implementation of the framework highly depends on collaborative governance efficacy. For instance, although Luoyang and Zhengzhou both belong to the “canal origin excavation section”, differences in urban planning standards and financial capacity may exist. This necessitates dovetailing the framework with higher-level decision-making processes—such as establishing a cross-city joint conservation center, formulating coordinated corridor construction guidelines led by provincial authorities, unifying core control standards, and conducting regular specialized inspections to ensure coherent implementation. (3) Stakeholder engagement: Effective implementation of the framework requires establishing robust community participation mechanisms. In living heritage areas like Hua County and Xun County, systems such as the “resident guardian” program and ecological compensation policies should be operationalized to transform local residents from passive observers into active beneficiaries and stakeholders, thereby translating spatial planning into collective action endorsed by the community. (4) Adaptive monitoring mechanism: An operable “Heritage Corridor Health Index” system should be established, covering indicators such as heritage preservation status, ecological connectivity, community satisfaction, and visitor experience. Through periodic evaluations, conservation strategies can be refined and optimized, enabling the framework to evolve into a sustainable, adaptive management system capable of continuous learning. In summary, the spatial optimization scheme proposed in this study serves as a scientific decision-making foundation for heritage conservation. Future research and practice should strive to deeply integrate such technical models with institutional analysis, stakeholder engagement, and adaptive governance, ultimately achieving sustainable conservation of large-scale linear cultural heritage.