jailcd2019-103： An ENVI-met Simulation Study on Urban Geometry in Local Climate Zone Scheme in Kokura City

Abstract

Artificial construction dramatically modifies the urban geometry and has a direct impact on urban climate. Urban climate condition is directly related to urban geometry configurations such as building size and height, the width of streets, contiguous or isolated buildings, green space, water bodies. Thermal conditions in a neighborhood are generally interactions of urban geometry with meteorological  elements including; solar radiation, air temperature, humidity, and wind speed. This paper presents an ENVI-met simulation approach to reveal the effect of Kokura urban geometry in local climate zones scheme against outdoor thermal comfort. Two environmental factors; air temperature, and wind velocity were chosen for utilizing ENVI-met software. The analysis was conducted to determine the influence of urban geometry on the distribution of air temperature and wind velocity in the local climate zone (LCZs). Variations in building height provide a good shadowing effect, H/W ratio and wider streets increase wind velocity. Vegetation around urban canyons provides lower air temperature. Compact urban geometry formed an urban ventilation and affects wind velocity. Higher wind velocity will affect the mean temperature for better urban local climate zones during the summer. Vegetation
has a better ability to balance the air temperature compared to water bodies in the local climate zone.