Relationship between Urban Morphological Properties and Ventilation in the Intensely Developed Areas of Inner Bangkok

Abstract

Bad urban ventilation is a major intimidation to Bangkok urban air environments. Nowadays, not only lack of research progress in this area due to the complexity of urban fabric, but also lack of awareness and knowledge about affiliations between urban morphological properties and human level air ventilation at microscale is a key factor that contravenes mitigation efforts in dense areas. The objective of this study is to find a relationship between urban morphological properties and urban air ventilation in various intensely developed environments of inner Bangkok that are investigated through computer simulation of field measurements secondary data input and flow analysis calculation on the basis of the geometry of the urban fabric. With regard to the innumerable number of parameters collected throughout a literature review, this study aims to identify the most important urban morphological parameters at urban block level (at the human level above ground) that affect air ventilation in Bangkok area. This study is the first part of the identification process of urban morphological properties of block types that may correlate with urban air ventilation. The results are as follows: “high density - low rise” type with parallel-to-prevailing-wind orientation (block no. 26) has the best urban ventilation efficiency, followed by “high density - high rise” type with a single, large and tall building, “high density - low rise” type with deviating-from-prevailing-wind orientation, “high density - high rise” type with parallel-to-prevailing-wind orientation, and “high density - high rise” type with deviating-from-prevailing-wind orientation, respectively. Building height and orientation are the two factors that are attributed to the parameterization of human level air ventilation.