Influence of Tropical Cyclones on Outdoor Wind Environment in High-Rise Residential Areas in Zhejiang Province, China

Tropical cyclones can cause tremendous harm to coastal areas. This research aims to explore the influence of tropical cyclones on outdoor wind environments in high-rise residential areas in the southeast coastal provinces of China, using Zhejiang Province as an example. It investigated four cities located in Zhejiang Province, including Taizhou and Wenzhou representing coastal cities, and Huzhou and Jiaxing representing inland cities, and collected data from 209 high-rise residential areas. Of these 209 samples, 131 high-rise residential areas with three typical spatial layouts (i.e., rows-style, free-style, and courtyard-style) have been selected for further studies. Numerical simulation was conducted to analyze the outdoor wind environment of these three types of high-rise residential areas, where the height of buildings was set as 26 floors (75 m), during tropical cyclones. Based on a comparison of the wind velocity at the horizontal planes of 1.5 m high and 10 m high, it was found that the spatial layouts of high-rise residential areas could mitigate the negative impact of tropical cyclones on the outdoor wind environment. Specifically, in the coastal cities, the courtyardstyle layout led to a relatively small proportion of high wind speed areas (e.g., wind velocity above 14.4 m/s) in the high-rise residential areas; and in the inland cities, the free-style layout led to a relatively small proportion of high wind speed area in the high-rise residential area. In turn, to better cope with the tropical cyclones, it was suggested that the courtyard-style layout should be recommended for high-rise residential areas located in the coastal cities and the free-style layout should be recommended for high-rise residential areas located in the inland cities in coastal provinces.