In situ characteristics and patterns of settlement spatial differentiation along the Grand Canal’s Tianjin Section

Abstract

The aim is to reveal the in situ patterns of spatial arrangement of rural settlements along the Tianjin Section of the Grand Canal. The research results indicate that: (1) Within the in situ scope of rural settlements, the resource conditions are characterized by adequate overall integrity and diversity, with lower evenness in comparison to diversity, and a relatively strong overall landscape advantage. (2) The in situ type classification results indicate 749 settlements can be categorized into four primary types and 16 subtypes. (3) The ferry and dock type and military garrison-type settlements under the canal transport-based type, the water transport and fishing type, the vegetable planting type, and the handicrafts type settlements under the industry-based type, the ancient city ruins type settlements under the history-based type, and the traditional craft type settlements under the folk-culture-based type all exhibit a distinct pattern of aggregation. (4) The spatial patterns of rural settlements follow multiple causal patterns.

Introduction

The Grand Canal in China has played a crucial historical role in shaping the destiny of the Chinese nation, connecting the exchanges and mutual learning between Chinese culture and different cultures around the world. As a vital transport artery in ancient China, the Grand Canal significantly influenced the development of towns and rural settlements along the canal. More than twenty cities have flourished along the canal, with numerous ancient towns and villages. As China’s urbanization accelerates, many rural canal settlements face issues such as insufficient awareness of cultural heritage, fading local traditions, and the destruction of historical relics. There is an urgent need to conduct research on the preservation and revitalization of these canal rural settlements.

Research on canal rural settlements covers a broad spectrum of fields, such as architectural science and engineering, culture, tourism, road and water transport, macroeconomic management and sustainable development, archeology, ancient Chinese history, transport economics, environmental science and resource utilization, water resources, and ecology. In recent years, there has been a noticeable increase in studies on the historical areas of the canal, traditional villages, the spatial evolution, morphological features, and landscape genes of towns and villages, and the spatial analysis of rural residential land and ancient town settlements, making them a focal point of research^{1,2,3,4,5,6,7,8}. Du et al. have applied spatial statistical analysis and historical-document research methods to investigate the spatial relationship between urban center distribution and river landforms in the Haihe Plain over the past 2200 years⁹. Huang and Yang. applied GIS to study the spatiotemporal evolution and distribution characteristics of the cultural heritage sites along the Suzhou Canal, revealing its evolution mechanism¹⁰. Huo et al. conducted a quantitative analysis of the spatial pattern and influencing factors of the rural settlements along the Shandong Section of the Grand Canal¹¹. Ikemoto et al. provided an in-depth explanation of the influence of historical irrigation canals on the urban form of Valencia, Spain, contributing to the reconstruction of urban green spaces in response to the increasing demand¹². With the ongoing economic development, canal settlement heritage tourism, and regional economic growth have become key topics of research¹³. Scholars like Zhao Xia have approached the integrated preservation and tourism development of settlement spaces from a theoretical perspective that includes historical cities, heritage corridors, and cultural routes^14,15. Buckman explored the development potential of canal cities by analyzing stakeholders’ views¹⁶. Ikemoto et al. performed a literature survey and field investigation to analyze the evolution of irrigation channels and urban development in the 20th century, examining the connection between urban form and historical water conservancy systems¹⁷. Bonetti et al. researched the influence of water body proximity and water quality on real estate prices, concluding that being near artificial canals is a positive characteristic that boosts property values¹⁸. Zhou et al. utilized principal component analysis to conduct a comprehensive evaluation of the defense abilities of coastal settlements during the Ming Dynasty, proposing that settlement accessibility is a key element influencing the city’s defense capacity¹⁹. Lu et al. applied spatial syntax to describe the traffic network structure and settlement distribution of the canal, road network, and salt-affairs-based settlements in the Huainan region²⁰. Moreover, scholars have analyzed the ecological wisdom of traditional rainwater management infrastructures such as rural ponds, canals, and permeable pavements from the perspective of stormwater management²¹.

The Tianjin Section of the Grand Canal (hereafter referred to as the Tianjin Section), as a gateway to the capital and a hub for river-sea transport, is not only a key passage for economic prosperity and cultural exchange along its route but also a fertile ground that has nurtured the growth of countless settlements, serving as a place rich in humanistic spirit and forging a unique and diverse cultural character. Currently, the overall spatial pattern of the rural settlements along the Tianjin Section remains relatively intact, with most of the settlement spaces aggregating in the suburban districts of Jinghai and Wuqing. Only a small number of original settlements in Xiqing and Beichen Districts have been preserved as distinctive village renovations. Many local characteristic resources have not been protected in time, and the in situ characteristics of canal rural settlement spaces need urgent protection and inheritance. In recent years, I have conducted quantitative analyses of the historical evolution of the rural settlement spaces along the Tianjin Section, the in situ characteristics of typical settlement spaces, and their current environmental conditions, exploring the in situ characteristics at a meso and micro scale^22,23,24,25. However, the settlement spaces along the Grand Canal vary in scale and exhibit a high degree of hierarchy and integrity, having been influenced for a long time by the canal’s historical culture and natural environment. Based on current research progress, existing studies on rural settlements along the Grand Canal have primarily focused on micro-scale morphological analysis or meso-scale regional comparisons. However, systematic investigations of settlement spatial patterns at the macro scale remain largely absent, particularly regarding the in situ characteristics and spatial differentiation patterns of rural settlements along the Tianjin Section. More critically, despite the widespread issues of ambiguous settlement boundary delineation and increasingly weakened local characteristics, most existing studies remain at the level of descriptive phenomena. In response, this study adopts a macro-scale perspective to fill this research gap by systematically identifying the in situ characteristics and spatial patterns of rural settlements along the Tianjin Section, thereby providing a solid analytical basis for addressing the practical problems of unclear settlement extent and diminishing local distinctiveness.

Methods

Overview

Tianjin is situated at 38°34′—40°15′ N latitude and 116°43′—118°4′ E longitude, in the northeastern part of the North China Plain, within the lower reaches of the Haihe River Basin²². The history of canal transport in Tianjin dates back to the Eastern Han and Cao Wei periods, when Cao Cao, in response to military needs, ordered the excavation of the Pinglu Canal, Quanzhou Canal, and Xinhe River, which laid the foundation for the region’s canal transport system²⁶. During the Sui and Tang Dynasties, Emperor Yang of the Sui Dynasty ordered the construction of the Yongji Canal to ensure the transport of military provisions to the northern border. With the opening of the “Lushui River Channeling”, Tianjin became a crucial hub for canal transport, and the gateway to the capital during the Jin Dynasty, and the Sancha River mouth became an important logistical node. During the Yuan, Ming, and Qing periods, maritime trade thrived, and Tianjin grew into a strategic location for the northern transport of grain, a vital economic link between the north and south, and the largest commercial distribution center in northern China. However, by the late Ming and early Qing periods, with river silting and the rise of maritime trade, canal transport gradually declined. The development of canal transport contributed to the prosperity of settlements in Tianjin, fostered cultural exchanges between the north and south, and solidified Tianjin’s role as a major water transport hub in northern China²⁷.

The study focuses on the settlements located along the South Canal and North Canal of the Tianjin Section, spanning a total of 187.6 km. The paper begins by outlining the spatial configuration of the canal rural settlements, followed by an analysis of the historical development of their in situ characteristics. Taking into account the cultural heritage along the Tianjin Section and the patterns of ancient travel, it determines the in situ scope of the canal rural settlements. There are 749 settlements—towns and villages—along the Tianjin Section, with a high density of distribution (Fig. 1).

Fig. 1: Scope of the study area.

a Location in China (Map Review Number: GS(2019)1682, Supervised by the Ministry of Natural Resources of China). b Location in Tianjin (Map Review Number: GS(2019)3333, Supervised by the Ministry of Natural Resources of China). c Location in the Tianjin Section, Grand Canal (Map Review Number: GS(2019)3333, Supervised by the Ministry of Natural Resources of China).

Data source

The data for this study mainly comprises basic data on the rural settlements along the Tianjin Section, land-use data, and cultural heritage data. The basic data for the rural settlements along the Tianjin Section includes both vector and raster data, with the majority of the data coming from the Resource and Environmental Science Data Center of the Chinese Academy of Sciences. This data encompasses Tianjin’s water systems, transport networks, and settlement distribution. The land-use data is sourced from the 30-m raster data of land-use remote sensing monitoring, generated by the Chinese Academy of Sciences using Landsat 8 satellite imagery and manually interpreted.

The cultural heritage data includes information on the heritage along the Tianjin Section, cultural protection units as provided by the cultural and tourism bureaus of various districts in Tianjin, immovable cultural relics, and intangible cultural heritage data at both the national and Tianjin municipal levels, available from the Tianjin Intangible Cultural Heritage website²² (Table 1).

Table 1 Sources of cultural data

Selection of research methods: the landscape pattern index construction method

The landscape pattern index construction method is used to quantitatively analyze the spatial pattern of the rural settlements along the Tianjin Section using landscape pattern index analysis. The Fragstats 4.2 software is used to conduct quantitative analysis based on indicators of landscape patch type and area, and landscape size, including patch type indexes: total patch area (CA), proportion of landscape area occupied by patch type (PLAND), number of patch (NP), patch density (PD), largest patch index (LPI), total edge length (TE), edge density (ED), landscape shape index (LSI); aggregation and connectivity index: aggregation index (AI), landscape division index (DIVISION), patch cohesion index (COHESION), connectivity index (CONNECT); diversity index: Shannon’s diversity index (SHDI), Simpson’s diversity index (SIDI), modified Simpson’s diversity index (MSIDI), Shannon’s evenness index (SHEI), Simpson’s evenness index (SIEI), modified Simpson’s evenness index (MSIEI)^28,29. The specific index meanings are shown in Table 2.

Table 2 The meanings of the selected landscape pattern indexes²⁸

The aggregation index (AI) in this study was calculated using 30 m resolution raster data, based on the following rationale (Table 3):

Table 3 Core parameter settings for fragstats and spatial analysis

First, data suitability. The 2020 land-use remote sensing monitoring data from the Chinese Academy of Sciences, a recognized authoritative source, provides native 30 m resolution consistent with Landsat 8 multispectral bands. Optimized through manual visual interpretation, the data ensure accurate patch boundary delineation and adjacency extraction.

Second, regional feature matching. The data are suitable for the unit scale of Tianjin Canal rural settlements, ranging from tens to hundreds of square meters, and their ‘small clusters, large dispersion’ characteristic. This resolution avoids excessive fragmentation caused by high-resolution data and prevents merging of small settlements and adjacency ambiguity caused by low-resolution data.

Third, alignment with research objectives. The chosen resolution meets the requirements of aggregation index analysis, simultaneously capturing adjacency relationships of individual settlement patches and the overall regional aggregation pattern, precisely matching the study goal of analyzing the spatial aggregation pattern of Tianjin Canal rural settlements.

Land-use data preprocessing steps:

Coordinate and format standardization. The original raster data in Albers projection (WGS84 datum) were reprojected to the CGCS2000 coordinate system using ArcGIS, eliminating spatial overlay errors and ensuring spatial consistency for analysis.

Precise study area clipping. Based on Tianjin’s 2020 administrative boundaries and canal vector data, village-level boundaries for the core study area were generated. The raster data were clipped using the ArcGIS “Extract by Mask” tool to remove irrelevant areas.

Class selection and merging. The secondary class “rural settlements” was extracted. Urban patches were removed according to town planning boundaries, and a 3×3 neighborhood filter was applied to smooth edges and eliminate isolated noise pixels, ensuring the purity of the study objects.

Data accuracy validation. Thirty 1 km × 1 km sample plots were selected and validated using Sentinel-2 imagery (10 m) and field data. Overall accuracy reached 92.3% with a Kappa coefficient of 0.89, meeting the requirements for landscape pattern analysis.

Selection of research methods: spatial analysis methods

The spatial analysis methods at the level of the spatial pattern of settlements include kernel density analysis and average nearest neighbor analysis. Kernel density analysis can visually reflect the aggregation degree of different local settlement types along the Tianjin Section, detecting local density variations of settlements through a distance attenuation function and expressing spatial distribution patterns via kernel density visualization. The average nearest neighbor calculates the average distance between each cluster and its nearest neighboring cluster to compute the nearest neighbor index. Based on the nearest neighbor index, z-scores, and p-values, the cluster distribution state of different local settlement types can be determined. When the nearest neighbor index is less than 1, it indicates a cluster settlement distribution, while a value greater than 1 suggests a dispersed or competitive distribution.

Research design

The approach to studying the local characteristics of the spatial patterns of the rural settlements along the Tianjin Section is outlined in Fig. 2.

Fig. 2

Research framework.

The first stage involves data collection, which includes both foundational data acquisition and the establishment of a rural settlement database for the canal. By gathering data on rural settlements, land use, and cultural heritage along the Tianjin Section, consulting local chronicles, literature, and government websites, and conducting extensive fieldwork, a comprehensive dataset for the rural settlements along the canal is created. The second stage is determining the in situ scope of the rural settlements along the Tianjin Section. Based on historical travel patterns and the distribution of cultural heritage, the in situ scope of rural settlements is determined, covering 749 settlements. The third stage involves analyzing the overall pattern characteristics of the rural settlements along the Tianjin Section. Using landscape index methods, the structural features, aggregation degree, connectivity, diversity, and evenness of the rural settlement areas are quantified, providing a clearer understanding of the overall spatial pattern. The fourth stage is the classification of the in situ types of settlements along the Tianjin Section. GIS analysis, conditional selection, and expert evaluation methods are employed to classify the settlements into four major types (canal transport-based, industry-based, history-based, and folk-culture-based), with 16 subtypes. The fifth stage analyzes the type differentiation patterns of these rural settlement spaces. Using GIS analysis, kernel density analysis, and average nearest neighbor analysis, the spatial distribution of the 16 local settlement types is quantified, and the spatial distribution patterns and in situ causal relationships are summarized.

Results

Determining the in situ scope of rural settlements along the Tianjin Section

Existing studies on canal settlements mainly define their research scope in the following ways: (1) Focusing on typical towns along the canal. Although substantial research has examined the evolution and distribution of canal settlements, most studies emphasize large cities or typical towns along the canal, with relatively limited attention to small towns and rural settlements³⁰. (2) Delineating settlements adjacent to the canal. Many existing studies select only those settlements directly adjoining the canal as their research scope, such as the settlements along the Tongji Canal of the Sui–Tang Grand Canal³¹ and those along the Lu Canal³². Some scholars delineate the rural settlements along the Tianjin Section by setting a 500-m range on both sides of the canal, identifying 241 rural settlements accordingly³³. (3) Classifying settlements based on different buffer zones along the canal. Some scholars establish GIS buffer zones of 10 km, 25 km, 60 km, 80 km, and 120 km along the Jining Section of the Grand Canal, calculating the percentage of settlement aggregation as the basis for interpreting spatial distribution patterns³⁴. Others determine the distribution of canal settlements by counting the number of towns and villages within 2 km, 5 km, and 10 km buffer zones around the canal³⁵. (4) Using the composition of cultural heritage along the canal as the basis for delineation. Many scholars determine canal settlements with reference to existing historic cities, towns, villages, and cultural heritage along the canal. For example, the overall spatial pattern of the Ningbo Section is primarily defined based on the distribution of cultural heritage sites along the canal³⁶. Some scholars propose that areas closely associated with the rise and decline of the canal, or those containing material and intangible cultural heritage along the canal, should serve as the basis for defining the protection planning scope of canal settlements³⁷. (5) Using an evaluation system for the value of canal settlements. For example, canal-related urban settlements in Shandong are delineated according to the core areas defined in the Implementation Plan for the Protection, Inheritance, and Utilization of the Grand Canal in Shandong Province. Eighteen counties (cities/districts) are selected as the screening range, followed by the development of evaluation indicators based on the composition of canal heritage, heritage value, current conditions, and continuity, to further identify canal settlements³⁸.

However, the above approaches to delineating the scope of canal settlements exhibit several limitations: (1) They fail to fully reflect the overall integrity and systematic characteristics of canal settlements. Most existing studies determine the research scope by selecting well-known historic cities, towns, and villages, which are typically major nodal settlements along the Grand Canal and often associated with significant hydraulic projects and prominent canal heritage features. Nevertheless, canal settlements span eight provinces and municipalities and 27 cities, encompassing a large number of settlements. Current delineation practices thus lack sufficient comprehensiveness and systematicity. (2) The criteria for defining canal settlement scope based on buffer zones are inconsistent. At present, the standards for buffer-zone delineation vary widely. For example, studies on the Tianjin and Tongzhou Sections define canal settlements using different distance thresholds—500 m on both sides of the canal for the Tianjin Section, and 2–10 km for the Tongzhou Section. In the Jining Section, buffer zones ranging from 10 to 120 km have been used. Such substantial differences hinder the comparability of canal settlement research across different regions. (3) Evaluation-based delineation approaches involve strong subjectivity, limiting cross-regional applicability. Some studies identify canal settlements by establishing evaluation criteria and applying expert scoring methods. This approach is complicated, requires extensive expert involvement, and the evaluation indicators and weighting schemes are prone to controversy, making it difficult for other regions to adopt or replicate. In response to these issues, and based on an extensive literature review and an understanding of historical travel patterns, this study constructs a GIS-based database of cultural heritage along the canal and develops a relatively objective method for defining the in situ spatial scope of canal settlements, representing a methodological innovation of this research.

Delimitation approach

(1) Spatial distance between rural settlements along the canal and the canal water system — determining the initial scope. Historical literature indicates that walking was the primary mode of transportation in ancient China. For instance, according to military mobility records, infantry could travel approximately 20–30 li per day, cavalry 60–80 li, and ordinary infantry about 30–40 li per day during a full day’s march.

As documented in Sibu Congkan (Jingbu, Maoshi, Volume 10): “I have donned my battle attire; thirty li the army marches. The annotation states: When the king commands the troops, he instructs them, ‘March thirty li per day before resting.’”

During the Qin and Han dynasties, postal stations were arranged every five li as a post, every ten li as a pavilion, and every thirty li as a courier station.

Wujing Zongyao also records: “During military marches, troops rest and reorganize every ten li, take dry rations at thirty li, and lodge at sixty li. Traditionally, thirty li constitute one she (a day’s march), and sixty li for forced marching; adjustments are made depending on urgency.”

The ancient unit “she” refers to the distance a military unit would travel in one day, equivalent to thirty li.

Based on historical travel distance, the spatial relationship between rural settlements and the Grand Canal was determined through the estimation of ancient mobility. Given that ordinary infantry could travel approximately 30–40 li within a full day, 30 li was selected as the standard one-day marching distance. Assuming canal-side wharfs or rural settlements as the point of departure, the maximum round-trip distance reachable within one day is therefore about 30 li, suggesting that the maximum one-way travel range of historical residents extended roughly 15 li on each side of the canal. Accordingly, a buffer zone was delineated along both sides of the Grand Canal using a 15-li range (≈8.8155 km, calculated according to the Ming Dynasty li system, as most rural settlements in Tianjin were established during the Ming period). This buffer represents the activity radius of historical residents and the spatial extent of settlement presence along the canal, and was used to determine the initial scope of the canal-side rural settlements.

(2) Relationship between cultural heritage resources along the canal and canal settlements. A GIS database of tangible cultural heritage along the regional Section of the canal is established. Seven categories of heritage resources are included: water infrastructure ruins, river-course remains, ancient architecture, ancient ruins, ancient tombs, stele inscriptions, and significant modern and contemporary historic sites and architecture. The database is compiled according to administrative divisions along the canal and records information such as heritage name, historical period, protection level, geographic coordinates, and detailed address, thereby forming a comprehensive GIS dataset.

A GIS database of intangible cultural heritage along the canal is also established. Ten categories of intangible heritage are included: traditional craftsmanship, traditional music, traditional dance, traditional fine arts, traditional drama, folk literature, traditional medicine, traditional sports, games and acrobatics, folk culture, and traditional performing arts. This database is similarly organized based on administrative divisions along the canal and documents heritage name, protection level, geographic coordinates, and detailed address. Based on the above datasets, thematic maps of canal cultural heritage are generated. Using GIS, thematic maps integrating tangible and intangible cultural heritage are produced to visualize the spatial distribution of cultural resources along the canal.

(3) Determining the in situ spatial scope of canal rural settlements. By generating thematic maps of cultural heritage along the Grand Canal and consulting historical documents and local chronicles, the relationships among cultural heritage resources, the canal, and rural settlements beyond the initial buffer zone are analyzed to further refine the in situ scope of canal rural settlements. If highly canal-related cultural heritage is located outside the initial range, the in situ scope should be correspondingly expanded. The administrative boundaries of rural settlements containing such cultural heritage beyond the 15-li range are incorporated as supplementary areas. Through this process, the final in situ spatial scope of canal rural settlements is established (Fig. 3).

Fig. 3

Research framework for delineating the in situ range of canal-side rural settlements.

The preliminary identification of the in situ scope

According to the method for determining the in situ scope of canal rural settlements, and through the analysis of the spatiotemporal distribution of canal rural settlements and the quantitative data of cultural heritage along the route, the in situ scope of the canal rural settlements is properly determined from a comprehensive perspective. Historical documents were reviewed, and 30 li was chosen as the typical daily marching distance for soldiers. Assuming that the docks or settlements along the canal banks are starting points, the round-trip distance to the dock or settlement in one day is approximately 30 li. The suitable daily walking distance for ancient people can be estimated as 15 li on each side of the canal. This research determines a 15-li buffer zone on each side of the Grand Canal. As most rural settlements in Tianjin were established in the Ming Dynasty, the actual distance of the buffer zone is approximately 8.8155 km according to the Ming Dynasty’s li system. This is used as the initial scope for selecting canal rural settlement spaces (Fig. 4). Based on the survey data, rural settlements with characteristics of continuity in appearance and local renewal are chosen as research subjects, while relocated, merged, or newly built rural settlements are excluded. Consequently, there are 732 canal rural settlements within the buffer zone (Figs. 4, 5).

Fig. 4

15-li buffer zone along the Tianjin Section.

Fig. 5

Settlement distribution in the 15-li buffer zone of the Tianjin Section.

Precise determination of the in situ scope

Using this technical approach, the in situ scope of the rural settlements along the Tianjin Section is established. (1) Through the analysis of the evolution of cultural heritage in the study area, we review the intangible and tangible cultural heritage databases for each district along the Tianjin Section (Figs. 6, 7). In the study area, there are 276 intangible cultural heritage sites and 958 tangible cultural heritage sites. (2) The 8.8125-km buffer zone is compared with the intangible and tangible cultural heritage data in the study area (Fig. 8), revealing that some cultural heritage sites, due to their significance, inheritance, and close association with the canal, can supplement the cultural heritage of the rural settlements along the Tianjin Section. (3) The relationship between the cultural heritage resources along the canal and the canal rural settlements is established, leading to the determination of the in situ scope of the rural settlements along the Tianjin Section. Tangible and intangible cultural heritage sites beyond the 15-li range are selected, and additional heritage resources relevant to the creation and development of the Grand Canal are incorporated, while unrelated resources are excluded (Fig. 9). (4) By linking the administrative boundaries of rural settlements within the 15-li range with the administrative districts of newly identified cultural heritage data, the in situ scope of the rural settlements along the Tianjin Section is determined (Figs. 10, 11), comprising 749 settlements.

Fig. 6

Intangible cultural heritage of each district in the study area.

Fig. 7

Tangible cultural heritage in each district of the study area.

Fig. 8

Overlay of cultural heritage and initial scope in the study area.

Fig. 9

Cultural heritage classification of districts along the Tianjin Section.

Fig. 10

Summary of the in situ heritage of the rural settlements along the Tianjin Section.

Fig. 11

In situ scope of the settlements along the Tianjin Section.

(1) In light of the travel practices of ancient people, we estimate the daily range they could travel to and from the canal’s docks or settlements. A starting range of 15 li (8.8125 km) on both sides of the canal is proposed as the initial step for determining the rural settlements along the canal. This approach helps avoid the issue of focusing only on typical towns or villages, or limiting the boundary of rural settlements to just those along the canal.

(2) GIS is applied to create databases for tangible and intangible cultural heritage along the canal, and thematic maps are produced. This facilitates a deeper understanding of the formation mechanisms and in situ characteristics of the rural settlements along the canal. Moreover, by assessing cultural heritage resources beyond the 15-li range, relevant heritage resources closely associated with the Grand Canal’s formation and development are included, while unrelated resources are excluded. This method offers a more thorough and objective understanding of the scope of cultural heritage in canal settlements, helping to clarify the in situ scope of the rural settlements along the canal (Table 4).

Table 4 Supplementary statistics of canal rural settlements

(3) By layering the administrative boundaries of rural regions within the 15-li buffer zone with the administrative boundaries of cultural heritage locations outside the buffer, we can determine the in situ scope of canal rural settlements. This method is more precise and effective compared to previous canal buffer-zone delineation approaches and provides a comprehensive and systematic evaluation of the in situ characteristics and planning status of canal rural settlements. It establishes a solid research foundation for the integrated development of rural settlement systems along the canal.

(4) This technique is also applicable to the delineation of settlement boundaries in various provinces, cities, counties, and districts along the Grand Canal. In the future, based on the types of rural settlements along the canal, further subdivisions can be made, such as those primarily influenced by canal transport, industry, history, or folk culture, all of which are closely tied to the Grand Canal.

Based on the In situ Spatial Scope of the Rural Settlements along the Tianjin Section, a total of 749 canal rural settlements were identified (Fig. 12). These settlements are distributed across districts/counties as follows: 397 in Wuqing District, 62 in Beichen District, 52 in Xiqing District, and 238 in Jinghai District (Fig. 13).

Fig. 12

The in situ spatial distribution of rural settlements along the Beijing-Hangzhou Grand Canal in Tianjin.

Fig. 13

Distribution of rural settlements along the Beijing-Hangzhou Grand Canal in Tianjin by District/County.

Characteristics of in situ space differentiation of the spatial patterns of the rural settlements along the Tianjin Section

From a comprehensive perspective, the in situ spatial differentiation characteristics of the spatial patterns of the rural settlements along the Tianjin Section are outlined: First, the overall pattern features are analyzed through the landscape index method; second, in situ types are summarized from the classification standards and type characteristics; third, the type differentiation patterns are investigated, focusing on four main types—canal transport, industry, history, and folk culture, and 16 subtypes.

Characteristics of overall patterns

The characteristics of the overall spatial patterns of rural settlements along the Tianjin Section are analyzed with the goal of quantifying the overall pattern features through the landscape pattern index software Fragstats. This approach aims to clarify the overall characteristics and underlying rules of the canal rural settlements’ spatial patterns. The foundational data for this research comes from the 2020 land-use remote sensing monitoring data (30 m raster data) from the Chinese Academy of Sciences, which was generated using Landsat 8 remote sensing imagery and manual visual interpretation based on the 2015 data. The research region covers the in situ scope of the rural settlements along the Tianjin Section, with the 30 m raster data extracted using the GIS mask extraction tool (Fig. 14).

Fig. 14

Land use types of rural settlement space along the Tianjin Section.

Characteristics of the overall spatial patterns

The study area of the rural settlement spaces along the Tianjin Section features characteristics of dramatic landscape changes and fertile, beautiful waters, presenting an ecological landscape of “rich water, lush greenery, high-quality resources, and serene scenery.” Regarding the characteristics of the overall spatial patterns (Table 5), in terms of land-use proportions, dry land holds the largest share at 122,587.7 hectares, with a PLAND of 67.98%, fulfilling the requirements for the matrix. The next largest proportions belong to village settlements, township land, and other built-up land, with PLAND values of 12.78%, 8.91%, and 3.93%, respectively. The NP value for village settlements is 660, and the LSI is 35.24, indicating that rural land patches are highly fragmented, numerous, and widely distributed. Township land shows an NP value of 50 and an LSI of 8.55, which suggests that it has a higher variety of patch types, a higher aggregation index (AI), and a better regional economy. River channels and reservoirs/ponds have a PLAND of 2.00% and 2.30%, and LSI values of 54.30 and 26.08, showing that the study area has a diverse and widely distributed water system. Forest land has a PLAND of 1.29% and an LSI of 14.40. High coverage grassland has a PLAND of 0.48% and an LSI of 12.17, while medium coverage grassland has a PLAND of 0.01% and an LSI of 1.88. This suggests that forested areas are less disturbed by human activity and remain in relatively good natural condition, while grasslands have lower ecological indicators, indicating strong human influence and simpler patch shapes.

Table 5 Characteristics of the overall spatial patterns of the Rural Settlement Spaces along the Tianjin Section (Analysis using Fragstats)

Aggregation and connectivity

The characteristics of the spatial patterns of rural settlements along the Tianjin Section are further analyzed in terms of aggregation and connectivity indexes (Table 6). The aggregation index (AI) for all types of land use in the study area is greater than 70, which indicates a high level of patch aggregation. From the DIVISION index, the DIVISION value for all types of patches is close to or equal to 1. Through cross-validation with NP, PD, and LSI, it was found that most land-use types in the study area exhibit a high degree of landscape separation. For land-use types with a high number of patches, high patch density, and complex landscape shapes (e.g., Dry Land, Reservoirs and Ponds, Village Settlements, and Other Built-up Land), the landscape is highly fragmented, patches are highly separated, and spatial continuity is weak. In contrast, for land-use types with a low number of patches, low patch density, and simple landscape shapes (e.g., Paddy Field, Sparse Forest Land, Lakes, and Medium Coverage Grassland), the landscape consists of a few independent patches, exhibiting a relatively simple and scattered pattern. According to the COHESION index, the COHESION values for all land types in the study area are approaching 100, showing that the distribution of patches in the overall space is becoming more focused, and the internal cohesion of the patches is increasing, leading to good natural connectivity. Regarding the CONNECT index, the values are generally low. Other forest land has the highest connectivity value at 33.33, followed by paddy fields, wetlands, township land, high coverage grassland, river channels, dry land, forest land, village settlements, other built-up land, and reservoirs/ponds, indicating that the overall ecological landscape’s habitat connectivity is relatively low.

Table 6 The aggregation and connectivity indexes of the rural settlement spaces along the Tianjin Section (analysis using Fragstats)

Diversity and evenness

The indexes of diversity and evenness can visually reflect the landscape level of spatial patterns in the study area (Table 7). Regarding diversity, the Shannon’s Diversity Index (SHDI) is 1.1386, the Simpson’s Diversity Index (SIDI) is 0.5109, and the Modified Simpson’s Diversity Index (MSIDI) is 0.7153, suggesting that the resource status and diversity within the rural settlement space of the Tianjin Section are relatively good. Regarding evenness, the Shannon’s Evenness Index (SHEI) is 0.4315, the Simpson’s Evenness Index (SIEI) is 0.5505, and the Modified Simpson’s Evenness Index (MSIEI) is 0.271. This shows that the evenness of the spatial pattern in the study area is lower compared to its diversity, with a higher overall landscape dominance.

Table 7 The indexes of the diversity and evenness of the study area (analysis using Fragstats)

Classification of in situ types

From the perspective of settlement-type characteristics, previous research on the types of canal settlements has primarily focused on several perspectives, including the spatial distribution patterns along the canal, the development process of canal systems, the production and distribution patterns of cultural heritage, settlement functions, the etymology of riverside village and town names, and livelihood strategies on both sides of the canal (Table 8). The typological classification of the overall spatial locality of rural settlements along the canal should comprehensively consider four levels of factors. First, the functional elements supporting grain transportation along the canal, including spatial distribution patterns, ferry terminals, warehouses, and hydraulic engineering facilities. Second, the driving factors sustaining the survival and reproduction of canal rural settlements are reflected in livelihood activities associated with settlement-based industries. Third, the historical elements shaping the distinctive landscape features of canal rural settlements are represented by heritage remains related to the canal. Fourth, the inheritance factors representing the diverse ways of life in canal rural settlements are embodied in folk culture.

Table 8 Current research status of canal settlement typology classification (analysis using Fragstats)

By consulting archival materials from district archives along the Tianjin Section of the canal, reviewing district, county, township, and village gazetteers, and conducting extensive field surveys, baseline data for 749 canal rural settlements were collected, covering cultural heritage or significant cultural resources, heritage categories, protection levels, and industrial characteristics. Based on the four major attributes of canal rural settlements, spatial characteristics of in situ distribution, historical and cultural context, natural environment, and economic-industrial structure, and drawing upon the four analytical dimensions identified above, four dominant in situ spatial types and sixteen subtypes of canal rural settlements were established. First, the canal transport-dominated type includes five subtypes: river channel terrain type, ferry and dock type, canal diversion and dredging type, warehouse zone type, and military garrison type. Second, the history-dominated type includes four subtypes: ancient city ruins type, architectural courtyard type, tombstone carving type, and prominent figures type. Third, the folk culture-dominated type includes three subtypes: traditional performance type, traditional craft type, and oral traditions type. Fourth, the industry-dominated type includes four subtypes: trade and commercial interaction type, water transport and fishing type, vegetable planting type, and handicrafts type (Fig. 15).

Fig. 15

Land type classification of the rural settlements along the Tianjin Section.

Standard of classification

The in situ classification process of the rural settlement spaces along the Tianjin Section employs a conditional, classified selection and expert evaluation method (Fig. 16). First, an information set of 749 canal rural settlements along the Tianjin Section is established, collecting data such as establishment time, immovable cultural heritage list, protection level, types of heritage, intangible cultural heritage list, protection level, characteristic industries, and types of industry. Second, the conditional method is used for preliminary determination of the dominant types: (1) For settlements established at the time of or after the canal excavation, located adjacent to the Grand Canal with existing canal remnants or related cultural resources, canal transport is prioritized as the dominant in situ type, with further determination of subtypes under the canal transport dominance; (2) Settlements founded before the canal excavation are prioritized as history-based types based on the significance of their historical resources; (3) Settlements with prominent and active characteristic industries can be classified as industry-based types; (4) Settlements possessing intangible cultural heritage or significant cultural resources are prioritized as folk culture-based types. Third, when dominant types and subtypes overlap, for township and village settlements along the Grand Canal, the dominant type is determined based on the overall positioning and the extent of revitalization of in situ types. For instance, Yangliuqing Town, recognized as a national historical and cultural town, with abundant tangible and intangible cultural heritage resources and a prominent characteristic industry, is known as the hometown of Chinese folk culture and arts, so its dominant type is classified as a folk culture-based type. For canal rural settlements, expert evaluation is used to rank the 16 local types and determine the dominant in situ type. This involves conducting interviews, surveys, and distributing questionnaires to 10 experts from the fields of history, culture, canal studies, toponymy, architecture, and urban planning, who score and rank the 16 local subtypes, serving as the basis for determining the in situ subtypes of canal rural settlements.

Fig. 16

Methods for classifying in situ types of the rural settlement spaces along the Tianjin Section.

The specific evaluation process is as follows: (1) Formation of an interdisciplinary expert panel. A team of ten senior experts was invited, covering the core dimensions of rural settlement research to ensure comprehensive perspectives and professional authority in the evaluation process. (2) Development of an importance rating scale. A quantitative questionnaire was designed for the 16 in situ subtypes, focusing on importance assessment. The scale ranges from 1 to 10, where a score of 1 indicates “very low importance, not relevant for subtype inclusion,” and a score of 10 indicates “extremely high importance, representing a core in situ subtype.” This standardized scoring framework ensures objectivity and consistency. (3) Implementation of systematic investigation and score ranking. Experts conducted dedicated assessments through field interviews, historical-document review, and on-site surveys. Based on the rating scale, each expert independently scored the in situ subtypes and completed an importance-based priority ranking. (4) Establishment of a divergence-resolution mechanism. For subtypes where expert opinions diverged, focused group discussions were organized to exchange and justify evaluation evidence. If disagreements persisted, a majority-vote rule was applied to determine the final scores and ranking, ensuring efficient progress of the evaluation process. (5) Consistency testing and reliability reporting. To verify the reliability of the expert scoring results, Kendall’s coefficient of concordance (Kendall’s W) was used to assess overall consistency among the ten experts, and Cohen’s kappa (Cohen’sκ) was applied to test pairwise agreement. The calculated Kendall’s W = 0.9826 indicates a high level of consensus in ranking, while the pairwise test between Expert 1 and Expert 2 yielded Cohen’sκ = 0.9231, confirming strong inter-rater agreement. Together, these indicators demonstrate the methodological robustness and reliability of the expert assessment. The detailed scoring and ranking results are presented in Fig. 16.

Figure 17 shows the four dominant types of rural settlements along the Tianjin Section after classification. It can be seen that there are 149 settlements of the canal transport-based type, 87 of the folk culture-based type, 132 of the history-based type, and 381 of the industry-based type. Figure 18 illustrates the 16 subtypes of canal settlements in Tianjin, among which the canal transport-based subtypes include 21 river channel terrain types, 30 ferry and dock types, 14 canal diversion and dredging types, 12 key warehouse zone types, and 72 military garrison types. The industry-based subtypes include 20 trade and commercial interaction subtypes, 40 water transport and fishing types, 225 vegetable planting types, and 96 handicrafts types. The history-based subtypes include 79 ancient city ruins types, 26 architectural courtyard types, 13 tombstone carving types, and 14 prominent figures types. The folk culture-based subtypes include 45 traditional handicraft types, 13 traditional performance types, and 29 oral tradition types.

Fig. 17

In situ types of the rural settlement spaces along the Tianjin Section (Type).

Fig. 18

In situ types of the settlement spaces along the Tianjin Section (Subtype).

Characteristics of Different Types. (1) Characteristics of Canal Transport-based Settlements. The canal transport-based type refers to settlements that were established, maintained, or performed important canal transport functions based on the history of canal transport, relying on the excavation of the canal. These include five types: river channel terrain type, ferry and dock type, canal diversion and dredging type, warehouse zone type, and military garrison type.

River channel terrain type. The natural geographical characteristics of the rural settlements along the Tianjin Section are mainly influenced by the “river channel terrain.” Settlements are often built along the embankments or separated by fields. Some of these canal villages are named based on the river channel terrain, such as those using terms like “zui,” “wan,” “tan,” or “kou.”³⁹ Examples of settlements named after “kou (mouth)” include Zouzui, Lizui, Pangzui, Yangjiazui, Wuzui, Chenzui, Dongniantuozui, and Xiniantuozui. Settlements named after “wan (bay)” include Lijiawanzi, Zhangwan, and Wanzi. Those named after “tan (shoal)” include Xiaohetan and Dahetan. Settlements named after “kou” include Dongjiakou, Xijiakou, Dakouzimen, Xiaokouzimen, Taokou, Shangpukou, Xiapukou, and Dashaozhikou.

Ferry and dock type. The Grand Canal in China features a highly developed waterway network, with numerous “docks and ferries” aggregating along its path. These spots became gathering places for merchants as well as cultural centers, playing an essential role in the development of industrial and commercial activities in the surrounding village settlements. “Ferries” are divided into private, official, and charitable types. Private ferries, which were the first to appear, were usually operated by local villagers near the canal. Official ferries were established by the government to assist the movement of messengers, while charitable ferries were funded by local merchants, gentry, or monks. In Emperor Kangxi’s reign, the northern Tianjin Section had 19 ferries, including Hankou Ferry, Shangpukou Ferry, and Lijiazui Ferry. The southern section had 18 ferries, such as Niantuozui Ferry, Yangliuqing Shangxia Ferry, and Liangjiazhuang Ferry. Jinghai County had 11 ferries, including Shuangtang Ferry, Duliuzhen Ferry, Hetan Ferry, and Chenguantun Ferry⁴⁰.

Canal diversion and dredging type. “The area is a region where multiple waterways converge… It is located at the tail end of the province, and during the transitional period of autumn, when excessive rainfall occurs, both the Grand Canal and the second waterway rise simultaneously, causing backflows and flooding, resulting in severe damage.” To manage these issues, key sections along the canal have been diverted and dredged to regulate the flow⁴¹. The northern Tianjin Section includes several such diversions: the Kuang’er Port diversion canal was established during Emperor Kangxi’s reign, with a dam width of 67 m and dredged in the 43rd year of Emperor Kangxi (1704); the Chenjia Gou diversion was established in the 9th year of Emperor Qianlong (1744) and dredged in the 13th year of Emperor Tongzhi (1874); the Jiajiakou diversion was created in the 11th year of Emperor Qianlong (1746) and dredged two years later; other diversions include the Nancang diversion, Huozui diversion, and Ditou diversion, all established in the 37th year of Emperor Qianlong (1772)⁴². Many rural settlements, including Majiakou’s New Lock diversion canal, Chaomidianwa to Gejuwa diversion ditch, Gejuwa South Marsh, Huojiazui diversion, and Ditou Village diversion, have also been dredged. Taokou in Beicang Town is named for its large peach grove, as the northern Grand Canal frequently breaches here, resulting in the growth of abundant peach trees along the riverbank.

Warehouse zone type. To strengthen control over grain transport, the Ming and Qing rulers implemented the major policy of constructing large warehouses for storing tribute grain. During Emperor Yongzheng’s reign (1723–1735), forty-eight warehouses were established in the northern region, with grain stored annually for southern transport and military supplies. According to the Official Records of the Yuan Dynasty, there were fourteen warehouses set up in Hexi. Some of the key ones include Beicang (used for grain storage and as a dock during the Yuan and Ming Dynasties), Nancang (in Tianmu Town, Beichen District, originally a large grain warehouse during the Yuan period), Shangcang (located 15.5 km south of Jixian County, a large grain warehouse built in the Tang Dynasty at the northernmost point of grain transport), Xiacang (28.5 km south of Jixian, a Tang Dynasty village), Dongcang (Dashahe Township, Wuqing District, a Yuan Dynasty warehouse), Xicang (another warehouse of the Yuan Dynasty in Dashahe), Junliangcheng (a military grain storage built in the Tang Dynasty), the grain market at Beicai Village in Wuqing (a grain trading hub during the Liao Dynasty), and Cangshang (formerly Xiaocang Village, a Ming Dynasty military station). In Daliang Town, Wuqing District, Chaomizhuang, originally a place where rice was parched for the military during the Liao Dynasty, it later became a settlement. The Qianmi and Houmi (front and back rice) factories on the eastern shore of the Jiyun River in Ninghe County were used for drying military grain during the Ming Dynasty.

Military garrison type. The military significance of Tianjin is notable, and the practice of “stationing soldiers and cultivating land” played a role in the establishment of many rural settlements along the canal. Numerous settlements along the Grand Canal are named using terms like “guan (official), tun (village), hu (household), zhuang (village), and ying (battalion).” Examples in Wuqing include Beixiaoying, Daying, Cuihuying, Huying, Baoying, Yangying, Zhenying, Dongzhangying, Qidongying, and Sanbaihuying. The Nankou guard post in Wuqing, located on the southern bank of the Liao River, historically served as a military outpost protecting the tribute grain. Zhangdazhuang (Zhangda) in Hedong District and Xiaxinzhuang (Dadaxinzhuang) in Nancaicun Town, Wuqing, were military stations during the Yuan Dynasty. Shaoziying in Baigutun Township, Wuqing District, was also named for its role as a station for soldiers in the Yuan Dynasty.

(2) Characteristics of Industry-based Settlements. Industry-based settlements include trade and commercial interaction type, water transport and fishing type, vegetable planting type, and handicrafts type. Trade and commercial interaction type. Places where canal boats and vehicles reach in all directions, with a gathering of various goods, are home to many rural settlements for trade and commercial interaction. Towns such as Hangou, Shangpukou, Taokou, Xigu, Yangliuqing, and Duliu are important hubs for merchants along the canal, featuring numerous shops and bustling markets. Water transport and fishing type. Along the Grand Canal, every rural settlement has boat households that facilitate the transfer of tribute grain and the transport of goods. Fishing also became a livelihood for many canal villages. The villages most involved in shipping along the North Canal are Huozui, Liutan, and Dingzigu, with a total of 258 households, averaging 86 per village. Vegetable planting type. The banks of the Grand Canal in China are well-irrigated, making them rich in fertility, while the land outside the banks is mostly dry. Settlements along the Grand Canal depend on it for the robust development of vegetable planting, resulting in a wide variety of produce. In Jinghai District, “the land along the canal is fertile with red soil, sweet taste, and good texture, making it ideal for growing vegetables and fruit trees⁴³.” Handicrafts type. Handicraft types in canal rural settlements are diverse, including local products such as Yangcun dried cakes, Duliu aged vinegar, and Shangzhuangzi winter vegetables. Reed mats were woven for grain transport boats along the canal to provide shelter from wind and rain. During the Ming Dynasty, Xichang Village on the eastern bank of the Northern Canal specialized in mat weaving.

(3) Characteristics of History-based Type Settlements. The history-based type includes ancient city ruins type, architectural courtyard type, tombstone carving type, and prominent figures type. Ancient city ruins type. Many settlements along the Tianjin Section have ancient city ruins, such as the Eastern Han Dynasty ruins of Dongpingshu ancient city in Xidiaotai Village, Jinghai. To the east of the village, beside the canal, is a poem composed by Emperor Qianlong during his stay at Diaotai Village. 500 m north of Chengshang Village in Wuqing is the site of the ancient Quanzhou from the early Western Han period. Since the Han Dynasty, this area has been an important water transport route and a major salt distribution hub. Architectural courtyard type. The rural settlements along the Tianjin Section are home to many architectural landmarks, including Hexiwu Mosque, Yangcun Mosque, Shi Family’s Mansion, Wenchang Library, and the Hou Family’s Residence. Tombstone carving type, such as the Shell Tomb, the Warring States tomb complex, and the Jinguantun Lock Stele of the South Canal, the Yangcun Public Office Stele, the Reverse Flow and Water Transport Stele, the Sun Songlin Tomb Stele, the Liao Dynasty Tomb in Dingfuzhuang, and the Fenghe Bridge Stele of the North Canal, among others. Prominent figures, such as the Yang Family’s Generals of Yingxi, are located in Dalong Village, Wuqing. It is the ancestral home of the famous Yang Family’s Generals of the Ming Dynasty. For generations, they safeguarded the motherland firmly in Yingxi with their utmost dedication.

(4) Characteristics of Folk Culture-based Type Settlements. Folk culture-based type settlements include traditional performance types, traditional craft types, and oral traditions types. Traditional performances type includes traditional music, dance, and martial arts, such as the Xiangyinfa Parade in Liuyuan Village, the Tongyi Stilt Performance in Wangqin Village, the Zhongying Martial Arts Association, the Tongle Stilt Performance in Shangpukou, and the Suijia Lion Dance in Beicang. Traditional craft types, including traditional craftsmanship and traditional fine arts, such as Yangliuqing woodblock New Year paintings, paper-cutting, the cultivation and storage of Shawo radishes, and the production of winter vegetables in Chenguantun. Oral traditions type, mainly referring to the folk legends passed down in the canal rural settlements, such as the legend of the male and female siblings in Sanli Village and Sanyi Village in northern Wuqing, the legend of Jiang Ziya in Shangjia Village, and the legend of the Yang Family’s Generals in Yuanmengkou Village, Jinghai.

Type differentiation patterns

The type differentiation pattern refers to the quantitative analysis of the 16 subtypes included in the four main types of spatial settlements along the Tianjin Section, using GIS spatial analysis, kernel density analysis, and nearest neighbor analysis. This process visually displays and analyzes the spatial differentiation patterns of the canal village settlements of the subtypes.

Canal Transport-based Type. A quantitative analysis of the distribution characteristics of the five subtypes of canal rural settlements, under the influence of the canal transport-based type in China, was conducted using ArcGIS, providing a more visual understanding of their spatial distribution patterns. There are 21 rural settlements of the river channel terrain type (Fig. 19a-1). From the spatial distribution perspective, the river channel terrain type settlements are more significantly influenced by natural geographic features and have a higher association with the canal. These settlements are distributed as follows: 3 in Wuqing District, 7 in Beichen District, 2 in Xiqing District, and 9 in Jinghai District. The spatial distribution of kernel density indicates high-value zones in Shuangkou Town, Beicang Town, and Shuangjie Town in Beichen District, Yangliuqing Town, Xinkou Town, and Liangwangzhuang Town in Xiqing District, and Jinghai Town and Liangtou Town in Jinghai District (Fig. 19a-2). According to the average nearest neighbor analysis, the average nearest neighbor ratio is 1.06 with a z-score of 0.51, and the distribution along the canal follows a random distribution pattern of “multiple points in central and southern regions” (Fig. 19a-3).

Fig. 19: Distribution patterns of the canal transport-based rural settlements along the Tianjin Section.

a-1 Spatial distribution of river channel terrain type, a-2 kernel density analysis of river channel terrain type, a-3 Average nearest neighbor analysis of river channel terrain type, b-1 Spatial distribution of ferry and dock type, b-2 kernel density analysis of ferry and dock type, b-3 Average nearest neighbor analysis of ferry and dock type, c-1 Spatial distribution of canal diversion/dredging type, c-2 kernel density analysis of canal diversion/dredging type, c-3 Average nearest neighbor analysis of canal diversion/dredging type, d-1 Spatial distribution of warehouse zone type, d-2 kernel density analysis of warehouse zone type, d-3 Average nearest neighbor analysis of warehouse zone type, e-1 Spatial distribution of military garrison type, e-2 kernel density analysis of military garrison type, e-3 Average nearest neighbor analysis of military garrison type.

There are 30 canal village settlements of the ferry and dock type along the Tianjin Section. In terms of spatial distribution, these settlements are located as follows: 9 in Wuqing District, 3 in Beichen District, 6 in Xiqing District, and 12 in Jinghai District (Fig. 19b-1). According to the spatial distribution of kernel density, the canal village settlements of the ferry and dock type along the canal are distributed relatively densely (Fig. 19b-2). High-value distribution areas include Nancaicun Town in Wuqing District and Xinkou Town in Xiqing District, while Jinghai District shows higher aggregation in Jinghai Town, Duliu Town, Liangtou Town, Shuangtang Town, Chengguantun Town, and Tangguantun Town. The average nearest neighbor analysis yields a nearest neighbor ratio of 0.83 and a z-score of -1.68, with the distribution along the canal following an aggregating distribution pattern of “one belt, multiple points” (Fig. 19b-3).

There are 14 canal rural settlements of the canal diversion and dredging type along the Tianjin Section. In terms of spatial distribution, these settlements are primarily located in areas along the river prone to frequent flooding. There are 5 settlements in Wuqing District, 7 in Beichen District, and 2 in Xiqing District (Fig. 19c-1). From the perspective of the spatial distribution of kernel density, high-value distribution areas include Dajianchang Town and Caozili Town in Wuqing District, Shuangjie Town, Shuangkou Town, and Tianmu Town in Beichen District, and Zhangjiawo Town and Xinkou Town in Xiqing District (Fig. 19c-2). According to the average nearest neighbor analysis, the nearest neighbor ratio is 0.89, with a z-score of -0.71, and the distribution along the canal follows a random distribution pattern of “multi-point dispersion” (Fig. 19c-3).

There are 12 canal rural settlements of the warehouse zone type along the Tianjin Section. In terms of spatial distribution, 7 are located in Wuqing District, 3 in Beichen District, 1 in Xiqing District, and 1 in Jinghai District (Fig. 19d-1). In terms of the spatial distribution of kernel density, high-value areas include Hexiwu Town, Nancaicun Town, and Sicundian Town in Wuqing District, Beicang Town and Tianmu Town in Beichen District, Zhangjiawo Town in Xiqing District, and Liangtou Town in Jinghai District (Fig. 19d-2). The average nearest neighbor analysis results show a nearest neighbor ratio of 0.47, a z-score of -0.71, with a random distribution pattern of “multi-point dispersion” along the canal (Fig. 19d-3).

There are 72 military garrison-type rural settlements along the Grand Canal in China. In terms of spatial distribution, 49 settlements are in Wuqing District, 3 in Beichen District, 21 in Xiqing District, and 18 in Jinghai District (Fig. 19e-1). Regarding the spatial distribution of kernel density, high-value areas are found in Hexiwu Town, Xiawuqi Town, Daliang Town, Damengzhuang Town, Sicundian Town, Xuguantun Street, and Dajianchang Town in Wuqing District, as well as Chengguantun Town and Tangguantun Town in Jinghai District. Duliu Town and Liangwangzhuang Township in Jinghai District, Shuangjie Town in Beichen District, and Xinkou Town and Zhangjiawo Town in Xiqing District show a more concentrated distribution (Fig. 19e-2). Based on the average nearest neighbor analysis, the nearest neighbor ratio is 0.62, and the z-score is −6.13, exhibiting the distribution pattern of “north–south aggregation” along the canal (Fig. 19e-3).

Industry-based Settlements. The canal rural settlements of the industry-based type include trade and commercial interaction type, water transport and fishing type, vegetable planting type, and handicrafts type, with their spatial distribution shown in Fig. 20. The canal rural settlements of the trade and commercial interaction type total 20. In terms of spatial distribution, 5 are located in Wuqing District, 2 in Beichen District, 4 in Xiqing District, and 9 in Jinghai District (Fig. 20a-11). Regarding the spatial distribution of kernel density, high-value areas are found in Duliu Town in Jinghai District and Yangliuqing Town in Xiqing District. In contrast, there is a lower distribution in Hexiwu Town and Nancaicun Town in Wuqing District, as well as Qingguang Town and Yixingbu Town in Beichen District (Fig. 20a-2). Based on the average nearest neighbor analysis, the average nearest neighbor ratio is 0.80, the z-score is −1.80, showing the distribution pattern of “central dual-core aggregation” along the canal (Fig. 20a-3).

Fig. 20: Distribution patterns of the Industry-based rural settlements along the Tianjin Section.

a-1 Spatial distribution of trade and commercial type, a-2 kernel density analysis of trade and commercial type, a-3 Average nearest neighbor analysis of trade and commercial type, b-1 Spatial distribution of water transport and fishing type, b-2 kernel density analysis of water transport and fishing type, b-3 Average nearest neighbor analysis of water transport and fishing type, c-1 Spatial distribution of vegetable planting type, c-2 kernel density analysis of vegetable planting type, c-3 Average nearest neighbor analysis of vegetable planting type, d-1 Spatial distribution of handicrafts type, d-2 kernel density analysis of handicrafts type, d-3 Average nearest neighbor analysis of handicrafts type.

There are 40 canal rural settlements of the water transport and fishing type. In terms of spatial distribution, 13 are located in Wuqing District, 3 in Beichen District, and 24 in Jinghai District (Fig. 20b-1). In terms of the spatial distribution of kernel density, high-value areas are found in Taitou Town and Liangtou Town in Jinghai District, as well as Wangqingtuo Town and Chenju Town in Wuqing District (Fig. 20b-2). The average nearest neighbor analysis results show a nearest neighbor ratio of 0.59, with a z-score of −4.93, and a distribution pattern of “multi-core aggregation” along the southern and central parts of the western side of the canal (Fig. 20b-3).

There are 225 canal rural settlements of the vegetable planting type. In terms of spatial distribution, 151 are located in Wuqing District, 13 in Beichen District, 10 in Xiqing District, and 51 in Jinghai District (Fig. 20c-1). The kernel density analysis reveals high-density areas in Hexiwu Town, Damengzhuang Town, Baigutun Town, Xiawuqi Town, Daliang Town, Nancaicun Town, Dajianchang Town, and Meichang Town in Wuqing District, while Taotou Town, Liangwangzhuang Township, Dafengdui Town, and Tangguantun Town in Jinghai District have relatively dense distributions (Fig. 20c-2). According to the average nearest neighbor analysis, the nearest neighbor ratio is 0.67, with a z-score of −9.25, showing a distribution pattern of “north–south aggregation mesh” along the canal (Fig. 20c-3).

There are 96 canal rural settlements of the handicrafts type. In terms of spatial distribution, there are 50 in Wuqing District, 7 in Beichen District, 8 in Xiqing District, and 31 in Jinghai District (Fig. 20d-1). The spatial distribution of kernel density shows high-value areas in Cuihuangkou Town, Meichang Town, and Caozili Town in Wuqing District, as well as Liangwangzhuang Township and Xizhaizhuang Town in Jinghai District. Densely distributed areas are found in Xiawuqi Town, Baigutun Town, Chenju Town in Wuqing District, Xinkou Town in Xiqing District, and Dafengdui Town, Tangguantun Town in Jinghai District (Fig. 20d-2). The average nearest neighbor analysis results indicate a nearest neighbor ratio of 0.82, with a z-score of −3.43, and a distribution pattern of “patch-like aggregation” along the canal (Fig. 20d-3).

History-based Settlements. Canal rural settlements of the history-based type include ancient city ruins type, architectural courtyard type, tombstone carvings type, and prominent figures type. Their spatial distribution is shown in Figs. 4–9. There are 79 canal rural settlements of the ancient city ruins type (Fig. 21). In terms of spatial distribution, 52 are in Wuqing District, 4 in Beichen District, 1 in Xiqing District, and 22 in Jinghai District (Fig. 21a-1). From the spatial distribution of kernel density, high-value areas are found in Gaocun Town, Hexiwu Town, Xiawuqi Town, Damengzhuang Town, Daliang Town, Chengguan Town, and Huangzhuang Street in Wuqing District, and Duliu Town, Jinghai Town, Chengguantun Town, Tangguantun Town, and Yanzhuang Town in Jinghai District (Fig. 21a-2). The average nearest neighbor analysis results show a nearest neighbor ratio of 0.75 with a z-score of −4.19, revealing a distribution pattern of “north–south aggregation” along the canal (Fig. 21a-3).

Fig. 21: Distribution patterns of the history-based rural settlements along the Tianjin Section.

a-1 Spatial distribution of ancient city ruins type, a-2 kernel density analysis of ancient city ruins type, a-3 Average nearest neighbor analysis of ancient city ruins type, b-1 Spatial distribution of architectural courtyard type, b-2 kernel density analysis of architectural courtyard type, b-3 Average nearest neighbor analysis of architectural courtyard type, c-1 Spatial distribution of tombstone carving type, c-2 kernel density analysis of tombstone carving type, c-3 Average nearest neighbor analysis of tombstone carving type, d-1 Spatial distribution of prominent figures type, d-2 kernel density analysis of prominent figures type, d-3 Average nearest neighbor analysis of prominent figures type.

There are 26 canal rural settlements of the architectural courtyard type (Fig. 21b-1). From the spatial distribution perspective, they are mainly located in Wuqing District (9 settlements), Beichen District (1 settlement), and Jinghai District (3 settlements). From the spatial distribution of kernel density perspective, Yangliuqing Town in Xiqing District, Duliu Town, and Jinghai Town in Jinghai District are high-value distribution areas (Fig. 21b-2). From the average nearest neighbor analysis, the nearest neighbor ratio is 0.90, with a z-score of −0.91, showing a random distribution pattern of “aggregation in the south” along the canal (Fig. 21b-3).

There are 13 canal rural settlements of the tombstone carving type (Fig. 21c-1). From the spatial distribution perspective, they are mainly located in Wuqing District (9 settlements), Beichen District (1 settlement), and Jinghai District (3 settlements). From the spatial distribution of kernel density perspective, Gaocun Town, Hexiwu Town, Nancaicun Town, Douzhangzhuang Town, and Dongpuwa Street in Wuqing District are high-value distribution areas. Chenguantun Town and Tangguantun Town in Jinghai District, as well as Shuangkou Town in Beichen District, have a small number of settlements (Fig. 21c-2). From the average nearest neighbor analysis, the nearest neighbor ratio is 1.01, with a z-score of 0.07, showing a random distribution pattern of “multi-point dispersion” along the canal (Fig. 21c-3).

There are 14 canal rural settlements of the prominent figures type (Fig. 21d-1). From the spatial distribution perspective, they are mainly located in Jinghai District (8 settlements), Xiqing District (3 settlements), and Wuqing District (3 settlements). In terms of the spatial distribution of kernel density, several settlements are distributed in Tangguantun Town in Jinghai District, Jingwu Town in Xiqing District, and Hexiwu Town in Wuqing District (Fig. 21d-2). From the average nearest neighbor analysis, the nearest neighbor ratio is 0.97, with a z-score of −0.19, showing a “dispersed point” distribution pattern along the canal (Fig. 21d-3).

Folk Culture-based Settlements. The folk culture-based rural settlements along the Grand Canal in China consist of the traditional performances type, the traditional handicrafts type, and the oral traditions type, as depicted in Fig. 22. There are 13 canal rural settlements of the traditional performance type (Fig. 22a-1). In terms of spatial distribution, 6 are located in Wuqing District, 2 in Beichen District, 2 in Xiqing District, and 3 in Jinghai District. Regarding the spatial distribution of kernel density, high-value areas are focused in Yangliuqing Town in Xiqing District, Chenju Town in Wuqing District, and Liangwangzhuang Township in Jinghai District (Fig. 22a-2). According to the average nearest neighbor analysis, the nearest neighbor ratio is 1.04, with a z-score of 0.29, and the canal area exhibits a random distribution pattern of “multi-point dispersion” (Fig. 22a-3).

Fig. 22: Distribution patterns of the folk culture-based rural settlements along the Tianjin Section.

a-1 Spatial distribution of traditional performances type, a-2 kernel density analysis of traditional performances type, a-3 Average nearest neighbor analysis of traditional performances type, b-1 Spatial distribution of traditional crafts type, b-2 kernel density analysis of traditional crafts type, b-3 Average nearest neighbor analysis of traditional crafts type, c-1 Spatial distribution of oral traditional type, c-2 kernel density analysis of oral traditional type, c-3 Average nearest neighbor analysis of oral traditional type.

There are 45 canal rural settlements of the traditional handicrafts type (Fig. 22b-1). From the spatial distribution perspective, there are 21 in Wuqing District, 3 in Beichen District, 2 in Xiqing District, and 19 in Jinghai District. In terms of the spatial distribution of kernel density, high-value areas aggregate in Caozili Town (Wuqing District), Chenguantun Town, Jinghai Town, and Dafengdui Town, Jinghai District (Fig. 22b-2). According to the average nearest neighbor analysis, the nearest neighbor ratio is 0.73, with a z-score of −3.41, showing a distribution pattern of “multi-core aggregation” along the canal (Fig. 22b-3).

There are 29 canal rural settlements of the oral traditions type (Fig. 22c-1). From the spatial distribution perspective, 10 are in Wuqing District, 1 in Beichen District, 3 in Xiqing District, and 15 in Jinghai District. High-value areas in terms of the spatial distribution of kernel density are aggregated in Yangzhuang Town and Ziya Town in Jinghai District, and Damengzhuang Town in Wuqing District. The distribution is denser in Xiawuqi Town and Daliang Town in Wuqing District, and Liangtou Town in Jinghai District (Fig. 22c-2). According to the average nearest neighbor analysis, the nearest neighbor ratio is 0.86, with a z-score of −1.42, and the distribution along the canal shows a random distribution pattern of “multi-point dispersion” (Fig. 22c-3).

In situ spatial patterns of the rural settlements along the Tianjin Section

In terms of the distribution quantity of in situ types of canal rural settlements in the Tianjin Section, the industry-based type has the highest number, followed by the canal transport-based type and history-based type, while the folk culture-based type has the lowest. Among the subtypes, the vegetable planting type and handicrafts type have the most settlements, followed by the ancient city ruins type and the military garrison type. The traditional handicrafts type, water transport and fishing type, and ferry and dock type have similar numbers, while warehouse zone type, traditional performances type, and tombstone carving type are the least.

From the perspective of the distribution of the main types specifically, industry-based settlements number 381, accounting for 50.87% of the total rural settlements along the canal. Canal transport-based settlements total 149, and history-based settlements gross 132, accounting for 19.89% and 17.62%, respectively. The folk culture-based settlements are 87, accounting for 11.62%.

As for the distribution of subtypes: (1) Among industry-based settlements, vegetable planting type leads with 59.06%, followed by handicrafts type (25.20%), water transport and fishing type (10.50%), and trade and commercial interaction type (5.25%). (2) For canal transport-based settlements, the military garrison type takes up 48.32%, followed by ferry and dock type (20.13%), river channel terrain type (14.10%), canal diversion and dredging type (9.40%), and warehouse zone type (8.05%).(3) History-based settlements are mainly composed of ancient city ruins type (59.85%), followed by architectural courtyard type (19.70%), prominent figures type (10.60%), and tombstone carving type (9.85%). (4) Folk culture-based settlements are predominantly traditional handicraft type (51.72%), followed by oral traditions type (33.34%) and traditional performances type (14.94%).

From the perspective of the spatial distribution pattern of rural settlements along the Tianjin Section, the settlements can be classified into four types: canal transport-based, industry-based, history-based, and folk culture-based. There are ferry and dock type, military garrison type, under the canal transport-based type; water transport and fishing type, vegetable planting type, and handicrafts type under the industry-based type; ancient city ruins type under the history-based type; and traditional craftsmanship type under the folk culture-based type. These types show distinct aggregation and distribution patterns along the Grand Canal. The specific distribution patterns are as follows:

In the canal transport-based rural settlements, canal villages along the river, based on the river channel terrain type, exhibit a random distribution pattern of “random multiple points in central and southern regions”, indicating that rural settlements in this region are largely constrained by the alignment of the canal and geomorphological characteristics, and are typically formed along riverbank spaces suitable for habitation and production, highlighting the dominant role of natural geographical factors; the ferry and dock type shows a distribution pattern of “one belt, multiple points”, as the transportation demands of canal shipping concentrated ferries and docks as water–land transfer hubs along the canal, where surrounding settlements gradually clustered around these transportation nodes; the canal diversion and dredging type and warehouse zone type show a distribution pattern of “multi-point dispersion”, which is directly associated with the spatial deployment of diversion-channel excavation and dredging projects during the canal-transport period. Moreover, the siting of warehouses needed to consider both transport convenience and material security, resulting in dispersed layouts aligned with engineering nodes and storage requirements; the military camp type displays a “north–south aggregation mesh” distribution pattern, reflecting historical military defense needs. The northern and southern sections of the Tianjin Canal served as strategic strongholds, where the concentrated placement of garrison sites stimulated settlement clustering and formed a north–south aggregation structure.

In the industry-based rural settlements, the commercial exchange type settlements along the canal show a distribution pattern of “dual-core central aggregation”, as the central section served as the core hub for Tianjin’s canal transport and regional commerce. High concentrations of people and goods reinforced commercial agglomeration effects, driving settlements to cluster around two major core nodes; the water transport and fishing type settlements present a distribution pattern of “central-southern multi-core aggregation”; the vegetable planting type displays a distribution pattern of “north–south aggregation mesh”, reflecting abundant fishery resources, fertile soils, and stable water supply along the canal, which supported fishery activities and vegetable cultivation and gradually generated a broad clustering pattern; the handicrafts type exhibits a distribution pattern of “patch-like aggregation”, as craft workshops relied on the canal’s advantages in raw material transport and product distribution, leading to clustering near raw material sources or locations with convenient transportation.

In the history-based rural settlements, the ancient city ruins type shows a distribution of “north–south aggregation” along the canal, corresponding to the historical administrative and military layout of the Tianjin Canal region. The northern and southern areas once served as political centers or strategic strongholds, and the continuity and development of ancient cities drove settlement clustering and resulted in a north–south aggregation pattern; the architectural courtyard type displays a random distribution pattern of “aggregation in the south”, as traditional canal-side architecture is better preserved in the southern section, where flat terrain and stable water sources, together with historical settlement inertia, supported the construction and transmission of traditional courtyard dwellings; the tombstone carving type follows a random distribution pattern of “multi-point dispersion”, because ancient burial sites were influenced by clan distribution, historical activity ranges, and geomantic considerations. Consequently, stone-carving relics were dispersed along clan settlements and historical activity paths; the prominent figures type follows a distribution pattern of “dispersed points”, as its pattern corresponds to the birthplace distribution, life trajectories, and migration routes of historical figures, resulting in an inherently random and scattered distribution.

In the folk culture-based rural settlements, the traditional performance types and oral traditions along the canal exhibit a random distribution pattern of “multi-point dispersion”, because the transmission of such folk cultural practices is closely embedded in everyday production and social life. Their spontaneous spread within local culture leads to dispersed distribution along the canal; the traditional craftsmanship type shows a “multi-core aggregation” distribution pattern, as the development of traditional crafts depends on master–apprentice transmission, forming core clusters of craftsmanship. Combined with the transport advantages of the canal for external product distribution, this gradually resulted in a multi-core agglomeration structure.

Discussion

An Bao and Ren Jidong’s research indicates that the Grand Canal has had a profound influence on the formation and development of rural settlements in Tianjin. Drawing upon historical documents, they argue that the emergence of rural villages along the canal is directly related to the spatial layout of military garrisons, warehouse zones, and local livelihood patterns³⁹. Building upon this foundation, the present study further expands the delineation of canal-influenced rural settlements and quantitatively analyzes the spatial distribution patterns of different locality-based types. Compared with existing studies that mainly focus on case analyses of typical towns and villages, this research systematically examines, from a holistic perspective, the spatial pattern characteristics and core regularities of rural settlements along the Tianjin Section, thereby providing a more comprehensive and in-depth understanding of their locality attributes. In addition, addressing the limitations of previous studies that predominantly adopted qualitative approaches to canal settlement morphology^41,42, this study employs GIS spatial analysis, kernel density estimation, and average nearest neighbor analysis to quantitatively assess the spatial locality types of Tianjin’s canal rural settlements. These methods not only enable a clearer visualization and interpretation of the mechanisms shaping their locality characteristics but also provide valuable academic references for the spatial conservation and sustainable development of canal rural settlements.

The spatial pattern and distribution characteristics of the rural settlements in the Tianjin Section are generally closely linked to river-course changes, water conservancy projects, and socio-cultural factors^44,45,46. By analyzing the characteristics of the in situ patterns of the rural settlements along the Tianjin Section, it is clear that the in situ characteristics of the rural settlements are influenced by multiple factors and interrelated causal patterns.

(1) The emergence of rural settlements along the Grand Canal in Tianjin is directly related to its status as a transport hub. The Grand Canal was dug during the Cao Wei period, which led to the rise of Tianjin settlements. In the Jin Dynasty, “Lushui River Transport” connected Jinghai to Yangliuqing and then turned eastward to “Xinan Haiyuan,” flowing upstream to Tongzhou, and the canal rural settlements during this period were in their developmental stage. The salt industry and stationed military in the Yuan Dynasty led to the establishment of settlements in southeastern Tianjin. Early inhabitants of Tianjin included military settlers, salt workers, southern coastal boatmen, river workers, and merchants. By the end of the Yuan Dynasty and the beginning of the Ming Dynasty, Tianjin had become a gateway to the capital and a transport hub, with stationed soldiers and immigrants settling along the canal, providing a significant labor force for canal operations. The construction of granaries also became a major function of certain settlements, such as the Fourteen Granaries (Dongxicang Village) during the Yuan Dynasty and the Beicang granary during the Qing Dynasty.

(2) Changes in canal transport promoted the prosperity and decline of industries in rural settlements. With the rise of canal transport, rural settlements along the Tianjin Section experienced significant changes in number, scale, type, and function. Commercial and industrial activities flourished, making these settlements representative towns along the canal for tax collection. Some rural settlements not only ensured smooth transport with ferries and docks but also became trading hubs, with thriving markets. However, with the cessation of canal transport, the once-thriving commercial activities faded, and many rural settlements along the canal shifted to self-sustaining, inward-focused models, gradually leading to decline.

(3) Historical and cultural relics provide evidence of the rise and fall of canal transport and rural settlements. The rural settlements along the Tianjin Section contain many important cultural relics, including the ancient city ruins, architectural courtyards, and tombstone carvings, which document the historical changes in canal transport and the development of these settlements. Some ruins of the ancient city, while located near the canal, predated its construction and rose or fell with canal transport, such as the ruins of the ancient city of Dongpingshu in Western Han in Xidiaotai Village, Jinghai District, and the ancient city of Quanzhou in Western Han in Chengshang Village, Wuqing District. Many fine and complete traditional architectural courtyards are mainly found in towns like Hexiwu, Shuangkou, Duliu, and Yangliuqing, while common villages contain numerous tombstone carving relics.

(4) Folk culture has been passed down as part of the history of the rural settlements along the Tianjin Section. Tianjin’s unique geographical advantage of integrated waterway transport has fostered a distinctive folk culture in its canal rural settlements, which continues to thrive today. Although the function of canal transport has ended, the folk culture that reflects the development and historical changes of the canal rural settlements continues to be passed on through generations. The canal settlements in Duliu Town and Beicang Town, influenced by canal transport culture, have a developed tradition of martial arts, such as Tongbei Boxing of Duliu Town, Bao-style Eight Extremes Boxing of Shuangjie Town, Zhao-style Tai Chi of Shuangkou Town, and Kaihe Tai Chi of Caozhuangzi Village, which are spread across the canal settlements. The traditional dance of Tianjin is marked by its unique “Tianjin” style, which draws from the stilt walkers’ techniques developed during their labor at the canal docks. This has resulted in the formation of special local traditions in Tianjin, such as the Yixing Fuyongchang High Stilt Performances Society, Wangzhuang Shunhe High Stilt Performances Society, Dingfuzhuang Xiliuxing Taiping Folk Performances Society, Dongyuzhuang Tongle Flower Drum (a Popular Folk Dance) Society, and Liu’anzhuang Tongxin High Stilt Performances Society, to name a few.

The spatial patterns of canal rural settlements, influenced by canal transport, industries, history, and folk culture, are mutually interrelated and causally connected. Canal-based infrastructure, such as docks, post stations, granaries, and government offices, is typically located at key nodes in the rural settlements along the canal. Likewise, commerce clusters at these key nodes, making them the focal points for trade. Consequently, the spatial patterns of the rural settlements along the Tianjin Section exhibit distinct causal patterns influenced by multiple local factors. Jia and colleagues conducted an in-depth analysis of embanked lake landscapes, suggesting that they bear the historical traces of human settlement construction and homeland formation, encapsulate the ancestral knowledge of natural environment, climate, hydrology, and geographic patterns, and convey information about hydraulic engineering technologies, social environments, and local folk culture across different periods and regions. This aligns closely with the findings of the present study. The in situ typological characteristics of canal rural settlements similarly embody extensive hydraulic knowledge, cultural imprints, production technologies, and folk craft skills. These in situ attributes not only provide a theoretical foundation for the preservation of Grand Canal cultural heritage in China but also offer important practical guidance for the contemporary renewal and development of settlements along the canal.

This study systematically elucidates the in situ scope, spatial patterns, and local characteristics of rural settlements along the Tianjin Section, thereby enriching the theoretical understanding. Initially, the spatial pattern of rural settlements along the Tianjin Section is characterized by a high degree of land-use patch aggregation, low ecological landscape habitat connectivity, a relatively lower spatial uniformity compared to diversity, and a higher overall landscape dominance. Secondly, among the four major types, the industry-based type is the most numerous, and the folk-culture-based type is the least. Within the subtypes, vegetable planting and handicrafts types are the most frequent, followed by ancient city ruins and military garrison types. Less common types include warehouse zone and tombstone carving types, and traditional performance types. The differentiation in types reveals that the distribution pattern of canal villages, primarily influenced by canal transport, is related to a “random multiple points in central and southern regions,” “multi-point dispersion,” and “north–south aggregation” pattern. The industry-based distribution follows a “central double-core aggregation,” “central-southern multi-core aggregation,” “north–south aggregation mesh,” and “patch-like aggregation” model. The history-based type follows patterns such as “north–south aggregation,” “random,” “multi-point dispersion,” and “dispersed points.” The folk-culture-based type follows the distribution patterns of “random multiple points” and “multi-core aggregation.” Lastly, the spatial pattern of rural settlements along the Grand Canal has distinct in situ characteristics. The in situ characteristics of the settlements along the Tianjin Section follow multiple causal patterns. The settlements’ origin is closely related to their role as a waterway hub; changes in the transport system have contributed to the growth and decline of settlement industries. Historical and cultural heritage ruins as evidence of the rise and fall of waterways and settlements over millennia, while folk culture preserves the history of the settlements along the Tianjin Section. Cultural Integration: The prosperity of the water transport system was the primary driver of the development of the rural settlement space along the Tianjin Section, leading to a variety of cultural types of the settlements that have integrated and collided to create a diverse multicultural landscape.

This study focuses on the core practical challenges in the spatial conservation of rural settlements along the Grand Canal’s Tianjin Section, targetedly addresses the practical problems of unclear conservation boundaries and identification of local characteristics, and provides research support for clarifying ideas related to protection and development. The findings not only provide a foundational reference for the value identification of the Grand Canal World Cultural Heritage but also demonstrates multi-dimensional application and research value at both practical and theoretical levels At the cultural heritage conservation level, the study helps to coordinate the locality characteristics and development potential of canal rural settlements within a regional from a holistic perspective, mitigating the tendency of fragmented conservation work. It also provides referential practical ideas for the systematic development of the Grand Canal Cultural Belt and the National Grand Canal Cultural Park. At the rural planning level, the research can provide references for clarifying development directions for canal rural settlements, optimizing spatial layout and resource allocation efficiency, and promoting the deep integration of cultural resources with rural revitalization, thus providing ideological support for the sustainable development of rural settlements.

Overall, this research builds a conceptual and methodological bridge connecting cultural heritage conservation, rural planning practice, and landscape theory and lays a foundation for subsequent explorations in related fields. This study still has certain limitations: First, it only focuses on canal rural settlements in the Tianjin Section; the representativeness of regional samples is limited, and the generalizability of the research conclusions needs to be further verified by combining canal settlements in other regions. Second, this study completed the determination of conservation scope, classification of local types, and analysis of spatial differentiation characteristics based on current surveys and sorting out of historical data; the practical adaptability and implementation effect of relevant conclusions lack long-term follow-up evaluation and dynamic feedback, which needs to be further tested in combination with actual protection planning and construction work. Future studies may further explore differentiated conservation pathways for canal rural settlements in different regions or integrate digital technologies to enhance the precision of spatial locality identification, thereby providing more targeted solutions for the conservation and development of rural settlements associated with cultural heritage.