Are urban form and function related to urban discourse? Insights from remote sensing and social media data for 15 major cities across the globe

Urban form and function are closely related to people's everyday lives. Understanding this relationship is essential for urban land-use planning. However, the variation of this relationship across cities has not yet been examined comprehensively at a global scale. This study investigates how urban form and function are associated with urban discourse across 15 major cities worldwide. We applied topic modeling to identify topics discussed in these cities using multilingual Twitter data. We utilized the remote sensing-based Local Climate Zones classification to represent urban form, applied spatial analysis to identify intra-urban areas with commercial function, and integrated these datasets within a unified analytical framework. Our results empirically reveal that urban discourse on Twitter is associated with urban form and function. For example, finance-related topics were more prevalent in compact urban forms with commercial function, whereas sports-related topics were more common in low-rise, non-commercial areas. However, this association is not consistent across all cities. Clear cross-city variation emerges, and topic concentrations can be grouped into three patterns: cross-regional, regionally distinct, and urban-form-independent. For instance, topics classified as “Food & Drinks”, “Real Estate”, and “Art” tend to follow the regionally distinct pattern. These patterns indicate that everyday activities and discourses among urban dwellers vary systematically across urban contexts rather than following a universal pattern. This analysis demonstrates an interwoven relationship between urban form, urban function, and urban discourse, providing insights into the social dimension of cities and informing spatial planning.