Modeling of urbanization effect on the simulation of wind fields in urban building environments and its application to air quality studies

Abstract:

The effect of urbanization on the simulation of wind fields and air quality in urban building environments was evaluated. The urban canopy model (UCM) parameterizations coupled to the WRF model were used to study urban processes, and their effect on the diurnal evolution of boundary layer structure in urban building environments. The study domain for modeling is the Seoul metropolitan area, which is typical urban building environment with high-densities and a broad range of multi-stories buildings. To create and compare urban land surface, the land cover was extracted from the Environmental Geographic Information System and the spatial data of the Seoul Metropolitan area for the Biotope Mapping Project. To apply UCM parameterization, the classification of urban surfaces was conducted. For the analysis, several meteorological variables were used during two specific time periods, i.e., day and night. Overall, large differences in wind fields were shown distinctly by urbanization effect. However, the magnitude of the differences was distinguished between the time periods. The differences in the wind components by urbanization effect were somewhat stronger during the day than at night, and it was likely that the marked decrease in the wind speed during the day was mainly caused by increased mechanical drag, turbulence production, and thermal effects. The urbanization effect showed a decrease of wind speed in the urban canopy layer for two specific times. Moreover, the urbanization effect on the simulation of wind fields was applied to air quality studies in urban building environments.

Acknowledgements: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2010-0012045).