Review on pollutant dispersion in urban areas-part A : effects of mechanical factors and urban morphology

Abstract

Cities are facing significant challenges due to low outdoor air quality. Hence, a growing number of studies have been conducted to develop strategies for improving air quality. This paper provides a comprehensive and systematic review of the mechanisms and effects of various mechanical measures and urban morphology on pollutant dispersion in an urban context. Moreover, a detailed quantification of the reduction potential of the mechanical measures and urban morphology is provided, followed by the identification of the critical urban factors for the practical urban optimizing strategies. Additionally, the two fundamental processes (mean flow and turbulence) affecting the pollutant dispersion are clarified to understand the dilution mechanism of pollutants. For these purposes, the reviewed papers are categorized into two groups: (i) Utilizing mechanical measures. (ii) Designing appropriate urban morphology. Generally, this study is useful for urban planners and architects who are responsible for decision-making.