Multicollinearity issue for the parameterization of urban ventilation potential with urban morphology

Abstract

The purpose of this paper is to verify the effectiveness of urban morphological parameters as variables that can be used in the system to assess the efficiency of urban ventilation and provide insight into the direction of future index improvement. Through a verification process performed by numerical analysis using CFD, urban ventilation performance is quantitatively reproduced for various building shapes, and the corresponding results are investigated in terms of relationship with urban morphological parameters. Although the urban ventilation performance can be well evaluated by urban morphology, the multicollinearity issue was raised due to the high correlation between parameters. To confirm this issue in the actual urban condition, the present work analyzed the correlation between parameters for the entire Tokyo area in Japan. The results showed high correlations between the building plan area ratio and the building frontal area ratio. However, the correlation coefficients are different depending on the vertical scale of urban configuration. Based on the analysis results, it was confirmed that understanding the spatial characteristics of urban areas is an important aspect of improving the evaluation system. This result provides essential information for developing an assessment system for urban sustainability and environmental performance using urban morphological parameters.