Effects of China’s urban form on urban air quality

Poor urban air quality in China has received global attention. This article analyses the extent to which the urban form of all provincial and prefectural cities in China affects urban air quality. A geographically weighted regression model was used to quantify the relationship between the urban form indices, as well as the satellite-derived pollutant column density of NO 2 and SO 2 . The results show that urban form has a significant effect on the urban air quality in China. The effect of urban form on air quality varies among the cities in this vast region. The compact ratio index is negatively correlated with both NO 2 and SO 2 column density for most of the cities. An ‘X’- or ‘H’-shaped city has less air pollution than a rhomboid-shaped city when the city is located in northern or central China. In comparison, the fractal dimension index is not a statistically significant predictor of air quality. Urban form can have effects on air quality that are equivalent to some meteorological and socioeconomic factors.