Analysis of urban morphological attributes and street level air pollution in high-density residential environments in Hong Kong

Air quality is a major concern for the quality of life in high-density urban environments. In most dense urban areas of Hong Kong air quality in street level does not depend only on the air pollutant emission rate, but also on dispersion rate. Air pollution dispersion is also a result of the physical built form; Urban Morphology. The study postulates an association between urban morphology and air quality. This paper presents a model to explain this street level air pollution phenomenon; relationship between street level air pollutant concentration and the morphology of hyper dense residential environments in Hong Kong. This study investigated 20 different high-density urban residential areas in five districts of Hong Kong through field measurements and statistical analysis. Real time street level air pollutants, microclimatic data and 21 urban morphological attributes were identified and calculated geometrically for the statistical analysis. The findings revealed that only limited numbers of micro level morphological attributes are distinguishable for street level air pollution. The finding also validating the theoretical assumptions and the method developed to model the relationship among morphological attributes, microclimatic conditions and street level air pollution phenomena which will be useful for future urban design and planning considerations.