Connecting Senses: The Cross-Modal Associations Between Smell and Vision in Understanding Urban Environments

Smell is a crucial yet understudied sensory dimension in urban environments, bridging tangible elements (e.g., exhaust, flowers) with intangible impacts on emotions, social interactions, and well-being. While geographical and urban research increasingly acknowledges multisensory experiences, much of geospatial analysis still emphasized the visual dimension. This research advances spatial thinking by examining cross-modal associations between smell and vision in urban environments. Specifically, we utilize advanced image processing techniques to extract visual cues from street view imagery (SVI) (i.e., Mapillary) and apply causal analysis to examine their effects on smell expectations recorded from participants. The results show that visual cues can predict smells in straightforward urban settings (e.g., parks or less densely populated areas). However, in complex urban environments, the predictive power of visual cues diminishes as diverse and overlapping scents obscure specific smells, even in visually distinct areas. These findings underscore the importance of a multisensory approach in urban analytics, enhancing our understanding of the interplay between sensory experiences and informing urban design strategies that integrate multiple senses to create engaging and inclusive environments. This is especially important for individuals with sensory impairments, such as anosmia or visual impairments, who rely on other senses to compensate for their perception of urban environments.