What do a thriving coral reef and a bustling city neighborhood have in common? More than you might think. A Perspective by Federico Botta and colleagues proposes a method for measuring urban vibrancy by studying cities the way ecologists study ecosystems, measuring the richness and abundance of human activities in urban spaces.
According to the authors, traditional measures of urban vitality, such as population density and land-use classifications, fail to capture the true dynamism of city life — what the authors call urban vibrancy. Their framework instead draws on biodiversity science, treating the variety of urban activities, from working and socializing to playing and learning, as analogous to species diversity in a natural habitat. The authors introduce a taxonomy of 13 activity categories based on how people actually use spaces, rather than how those spaces were designated. The model also applies ecological concepts such as carrying capacity and niche differentiation to urban planning, helping explain when neighborhoods risk losing vibrancy through overcrowding or conflict between activities.
The researchers envision combining mobile data, street-level imagery, and AI to detect activities in real time, while highlighting important ethical considerations around privacy and inclusivity. The authors call on researchers across computer science, ecology, geography, and urban policy to develop the urban vibrancy framework through pilot studies in cities worldwide.
PNAS Nexus
Urban vibrancy: An analogy of biodiversity, retail diversity, and activity-based urban diversity measures
19-May-2026