Urban Ventilation Strategies for Micro Climate Improvement in Subtropical High-density Cities: A Case Study of Tai Po Market in Hong Kong

Abstract

The process of urbanization has changed the surface properties and spatial structures of urban areas, and accordingly, induced urban climate change. A warming trend has been observed in many cities of China, associated with severe heat events in summer. Previous studies have found that improving air ventilation in one of the most effective methods to enhance thermal comfort under the hot and humid summer of subtropical cities. Aiming at improving urban microclimate and enhancing human thermal comfort, this paper develops urban regeneration strategies based on the case study of Tai Po Market in Hong Kong. Firstly, the three zones of Tai Po Market: compact mid-rise zone, open high-rise zone and sparsely built zone are defined and analyzed in the aspects of urban morphology and microclimate. Secondly, land use change, traffic reorganization and building transformation are recommended for solving the existing air ventilation problems in Tai Po Market. Finally, Economic and technical indexes, Sky View Factor, and wind speed at pedestrian level (based on computational fluid dynamics simulation results) are compared to verify the possibility of wind environment improvement through urban morphology optimization under the same density. 关键词： 高密度区域 ；通风 ；高温高湿夏季 ；形态优化 ；量化评估 ；流体动力学模拟