Shaping relational value in linear cultural heritage through green open spaces: insights from the Grand Canal

The focus of sustainable heritage development has shifted from the isolated preservation of physical vestiges to the continuous construction of symbiotic relationships among the heritage, the public, and the environment. As critical areas for such interactions, green open spaces facilitate the cultivation of relational values. Drawing upon the Historic Urban Landscape (HUL) perspective and the Cultural Values Model (CVM), this study establishes an interpretative indicator framework encompassing the forms, practices, and relations of green open spaces along linear cultural heritage. Utilizing the Chinese-BERT-wwm model, we analysed 85,244 social media posts across 61 green open spaces along the Grand Canal, achieving an average classification accuracy of 91.20%. The findings indicate that: (1) aesthetic appreciation remained the most prominent relational value, while historical value exhibits the strongest spatial heterogeneity and has increased overall over the decade following the World Heritage inscription; (2) three spatial typologies were identified through hierarchical clustering: the Heritage Identity and Memory Category, the Eco-Aesthetic Appreciation Category, and the Social Interaction Engagement Category; (3) at the level of green open spaces, historical value is enhanced by viewing activities, while social interaction is driven by consumption activities. Although vegetation and water bodies foster aesthetic appreciation, canal-related water bodies exhibit an inhibitory effect on it. Conversely, at the individual level, canal-related water bodies serve as core anchors for historical value and sense of place. By operationalizing relational values into four observable dimensions—historical value, aesthetic appreciation, sense of place, and social interaction—the research establishes a robust and transferable theoretical and methodological framework. This approach not only elucidates the catalytic role of green open spaces in enhancing relational values within linear cultural heritage but also provides evidence-based practical recommendations that bridge theoretical significance and management practice for global linear cultural heritage.