典型浅街峡谷布局及其植物配置模式春季花粉飞散特征模拟研究

城市中的气传花粉已成为春秋季节性过敏的主要过敏原之一，研究典型建筑布局及其植物配置模式下花粉飞散特征能够为合理优化城市绿地配置提供数据支撑，为花粉飞散研究提供补充。基于北京市海淀区校园绿地春季观测数据，提取3个采样地街谷布局和植物特征参数，借助CFD平台构建15个典型浅街峡谷布局及其植物配置模式参数化场景，探究不同场景下花粉飞散特征和距离阈值。研究结果表明：(1)花粉高浓度区位于风速较低、空气流动性较差的区域，花粉低浓度区位于风速高、空气流动性较好的地方。(2)4种植物配置模式的花粉飞散特征表现为行道树式>散点式>行道树+组团种植>组团式，花粉沉降特征表现为组团式>行道树+组团种植>行道树式>散点式。错列式布局结合行道树式植物配置花粉浓度降低率最高为24.89%,飞散效果相对更好。围合式布局结合组团式植物配置花粉浓度降低率最低为7.31%,聚积效果相对较好。(3)受不同建筑、植物和风场的影响，3类建筑布局花粉飞散距离远近依次为行列式>围合式>错列式，行列式需要约35—75m的飞散距离，围合式需要约28—60m的飞散距离，错列式需要约20—...

Simulation study on the characteristics of spring pollen scattering in typical shallow street canyon layout and plant configuration mode

Airborne pollen in cities has become one of the main allergens of seasonal allergy in spring and autumn. Studying pollen dispersion characteristics under typical building layouts and their plant configuration patterns can provide data support for rational optimization of urban green space configuration and complement pollen dispersion studies. Based on the spring observation data of the campus green space in Haidian District, Beijing, the street valley layout and plant characteristics parameters of three sampling sites were extracted, and 15 parametric scenarios of typical shallow street valley layouts and their plant configuration patterns were constructed with the help of Computational Fluid Dynamics platform to explore the pollen dispersion characteristics and distance thresholds under different scenarios. The results show that:① the area with high pollen concentration is located in the area with low wind speed and poor air mobility, and the area with low pollen concentration is located in the area with high wind speed and good air mobility. ② The pollen dispersion characteristics of four plant configuration patterns are shown as street tree type > scattered > street tree+group planting > grouped type, and the pollen deposition characteristics are shown as grouped type > street tree+group planting > street tree type > scattered. The highest pollen concentration reduction rate of 24.89% was achieved by staggered layout combined with street tree type planting configuration, and the dispersal effect was relatively better. The back-shaped layout combined with group planting configuration has the lowest pollen concentration reduction rate of 7.31%, and the aggregation effect is relatively better. ③ Influenced by different buildings, plants and wind field, the pollen dispersion distance of three types of building layout is in the order of rowed > back-shaped > staggered, rowed need about 35-75m dispersion distance, back-shaped need about 28-60m dispersion distance, staggered need about 20-53m dispersion distance. Plants with low wind speed, high pollen concentration and close dispersion distance are easy to accumulate, while plants with high wind speed, low pollen concentration and long dispersion distance are easy to disperse.