Evaluation and Validation of Urban Ventilation Potential for Heat Mitigation

Improving urban heat environments through enhanced ventilation has become a critical strategy for mitigating heat stress in the context of climate change. Taiwan’s high-density urban development and tightly packed buildings create significant variations in ventilation potential across regions. This study develops and validates a model for estimating pedestrian-scale wind speeds, offering a scientific basis for urban ventilation planning and thermal comfort improvement.

Using 10-meter wind speed data from the Taiwan Climate Change Projection Information and Adaptation Knowledge Platform (TCCIP) and observations from the Central Weather Administration, this study incorporates geographic information systems (GIS) to calculate surface roughness lengths and terrain coefficients. Pedestrian-scale wind speeds at a height of 2 meters were estimated using the power law and validated through measurements at three social housing sites in Taipei. Computational fluid dynamics (CFD) simulations were employed to analyze ventilation efficiency at the street-block scale, ensuring consistency with observed data.

Results demonstrate a strong correlation between modeled wind speeds and measured data, confirming the method's applicability under diverse environmental conditions. CFD simulations provided detailed insights into microclimate ventilation potential, highlighting spatial distribution patterns that align with observations. This study establishes a rapid, reliable model for evaluating urban ventilation potential, identifying pathways that reduce heat accumulation, enhance urban thermal comfort, and improve resilience against climate change impacts.

By integrating measurement validation and advanced modeling, this research offers a robust tool for urban planners and policymakers, supporting data-driven strategies to optimize urban ventilation and mitigate the effects of heat in densely built environments.