Impact of Block Spatial Optimization and Vegetation Configuration on the Reduction of PM 2.5 Concentrations: A Roadmap towards Green Transformation and Sustainable Development

The article aims to reduce PM 2.5 concentration by improving the spatial comfort of blocks and the vegetation configuration. It mainly analyzes the impact of the following five aspects on the PM 2.5 concentration distribution in blocks, including different angles between the prevailing wind direction and blocks, different vegetation types, the distance between vegetation and buildings, vegetation height and building height, and different street tree configuration types on both sides of the block. The results show that: when the street angle is 45 degrees, the PM 2.5 concentration in the air is the lowest. The PM 2.5 concentration in the air is significantly improved when the enclosed vegetation type (F1–F2) is planted, and the spacing between vegetation and buildings has no obvious effect on PM 2.5 concentration distribution. There is a negative correlation between the height of vegetation on both sides and the PM 2.5 concentration. At the height of 6 m, the PM 2.5 concentrations on the windward and leeward sides are relatively balanced. When the street trees are evenly distributed, they have the least effect on reducing PM 2.5 concentrations. However, the richer the distribution levels of street trees, the more obvious the effect on reducing PM 2.5 concentrations.