Associations between summer wind environment and urban physical indicators in commercial blocks based on field measurement and simulation in Xi'an

As a major driving force to improve economic output, commercial blocks also play a significant role in enhancing urban vitality. Due to its characteristics of high building density and large building volume, many wind environment problems are likely to appear in commercial blocks. In this research, we simulated the wind environment of four theoretical block models and real commercial blocks in STREAM software. The results suggest that under the same other conditions, the wind speed inside the block is the lowest when its building footprint ratio reaches about 56%. When the building footprint ratio is greater than 56.3% and gradually increasing, or less than 39.1% and gradually decreasing, the wind speed both inside and around the block will be steadily increased. In addition, we also found the quantitative correlations between the wind environment and other urban physical indicators, such as mean building height, stagger ratio of building height and enclosure degree, according to which we proposed the adjustment strategies of the spatial form of commercial blocks. Finally, we used four cases to verify the effectiveness of these strategies in optimizing the wind environment of commercial blocks.