<b>Comparative Analysis of the Urban Ventilation Characteristics between the Old and New Central Business Districts of Bangkok, Thailand</b>

Abstract

Urban heat islands (UHIs) are a global phenomenon of concern, especially in megacities such as Bangkok and Thailand. Addressing UHI effects requires an understanding of their connection to urban spatial structures, with urban ventilation playing a crucial role. This study compared the ventilation characteristics of Bangkok's Yaowarat and Ratchadamri central business districts (CBDs). Utilizing 2022 field measurements, spatial analysis, and computational fluid dynamics (CFD) simulations, this study examined the key factors influencing urban ventilation, primarily wind velocity and open space ratio within a 100meter radius. Each CBD exhibits distinct ventilation characteristics that are attributable to its unique topography. Yaowarat, characterized by compact low-to mid-rise buildings, manifests poorer ventilation than Ratchadamri, characterized by compact high-rise structures complemented by open spaces, which is consistent across both methods. Yaowarat recorded wind velocity (WV) levels below 1 m/s, while Ratchadamri typically registered WV levels exceeding 1 m/s. However, both areas still exhibited suboptimal ventilation and required improvements in WV. This study highlighted the significance of urban climatology in Thailand, raised stakeholder awareness, and emphasized the value of combining field measurements and CFD simulations to inform urban planning decisions for adapting urban ventilation related to UHIs.