Disentangling relations between urban form and urban accessibility for resilience to extreme weather and climate events: Fid-Bau Portal

Disentangling relations between urban form and urban accessibility for resilience to extreme weather and climate events

Hao, Haiyan / Wang, Yan

Highlights • Investigated relations between urban form and urban accessibility. • Simulated cities with varied urban forms mimicking different land-use developments. • Mixed-use urban forms are more self-sufficient and accessible when affected. • Decentralized population and facility distributions mitigate hazard risks. • Provided evidence-based localized planning strategies for urban resilience.

Abstract The rapid urbanization progress has placed large populations and expensive civil infrastructure at locations exposed to climatic and weather-related hazards (e.g., wind storms and floods), which demands informed and effective planning approaches that help human communities adapt to these adverse events. Emerging research highlights the importance of maintaining sufficient and equitable access to facilities that provide essential resources (e.g., gas and food) and services (e.g., healthcare and banking) and support city residents’ daily activities to avoid exacerbated event impacts. Extant studies suggest that urban forms, including the spatial arrangement of facilities, influence place accessibility. However, these studies are mostly semantic and ontological without quantitative investigations into their dynamic interactions under the impact of extreme (weather and climate) events (EEs). Therefore, we propose to evaluate the relations between urban form characteristics (i.e., compacity, polycentricity, and mixed land use) and urban accessibility with simulations. We used Cellular Automata (CA) to simulate four land-use change scenarios for the City of Tallahassee in the United States, and calculated the resource/service-seeking travel paths for “residents” living in the four “simulated cities” characterized by different urban form characteristics across three scenarios, i.e., business-as-usual (BAU), limited resource provision (LRP), and built environment disruption (BED) scenarios. We measured accessibility for a simulated city as the distribution (i.e., median values and cumulative distribution functions) of the calculated travel path lengths for that city. The simulation results indicate that “residents” living in cities with mixed land use and decentralized population and commercial centers are associated with higher-level accessibilities and experience fewer perturbations during EE. The research findings could inform future land use and landscape planning practices and policies that help hazard-prone communities adapt to recurring EEs and thus enhance community resilience.