Cultural transmission ability of urban heritage along the Jiangsu section of the Beijing–Hangzhou Grand Canal

The Beijing-Hangzhou Grand Canal, the world’s longest man-made waterway, has had a profound impact on Chinese social, economic, and cultural development, forming a typical linear cultural belt. This study focuses on the urban heritage of cities along its Jiangsu section. Social media data from platforms such as Douyin and Weibo were collected, and a quantitative evaluation system was developed using the Entropy Weight-TOPSIS method to assess the cultural transmission ability (CTA) of heritage sites and analyze key influencing factors. Spatial analysis methods were applied to examine distribution patterns. The results show that: (1) secondary dissemination indicators, including Weibo reposts and Douyin favorites and shares, contribute over 43% to CTA; (2) CTA exhibits spatial clustering, mainly in Suzhou, Wuxi, and Yangzhou; (3) CTA is positively correlated with heritage site concentration, and well-developed transportation infrastructure promotes transmission; (4) architectural heritage has significantly higher CTA than archaeological and burial sites.