| 摘要: |
| 行道树可以通过其树冠的遮阴及蒸腾作用有效改善城市街道热环境。悬铃木因其冠大荫浓、耐修剪整形的特性被广泛用作行道树。选取杭州市典型街谷
为例，采用ENVI-met数值模拟的方法探讨了悬铃木树形结构对街道峡谷小气候及行人热舒适的影响。结果表明，悬铃木树冠形态和枝叶密度对街道气温及相对
湿度影响较小，而树形结构对街道风速具有明显的调节作用。悬铃木树形结构能够有效降低街道平均辐射温度(MRT)，尤其在容易产生热应激的午后时段，平均
辐射温度可以减少13 ℃。研究结果可以为城市道路绿化规划设计及修剪管理提供参考，以提升街道行人热舒适和热安全。 |
| 关键词: 风景园林 街道峡谷 悬铃木 树形结构 热舒适 |
| DOI：10.19775/j.cla.2025.04.0123 |
| 投稿时间：2023-08-24修订日期：2023-12-30 |
| 基金项目:国家自然科学基金项目(51508515)；浙江省基础公益研究计划(LGF21E080001) |
|
| The Effect of the Tree Structure of Platanus on the Microclimate and Pedestrian Thermal Comfort inUrban Street |
| WANG Han,,HU Yanjun,,YAN Hai*,,WU Renwu,,BAO Zhiyi |
| Abstract: |
| As a beautiful landscape in the urban ecosystem, street trees not
only beautify every corner of the city, but also provide a lot of benefits for urban
residents with their unique ecological functions. Among them, the shading
effect and transpiration of the tree canopy become an important means for
street trees to improve the thermal environment of urban streets. In the hot
summer, the canopy of street trees is like a huge umbrella, providing a cool
shelter for pedestrians, and at the same time, the water released by its leaves
through transpiration also helps to reduce the temperature of the surrounding
environment, bringing a touch of coolness to the city. Among the many species
of street trees, Platanus has become a leader in urban greening because of its
large crown, dense shade, rapid growth, and resistance to pruning and shaping.
With its wide canopy and dense foliage, the Platanus tree provides ample shade
for the street. At the same time, its trunk is straight and its branches are easy
to prune, which makes the balsam tree able to meet the demand for shade and
maintain a clean and beautiful street image when used as a street tree. In order
to deeply investigate the influence of the tree structure of Pterocarpus indicus
on the microclimate of urban streets and the thermal comfort of pedestrians,
the researchers selected a typical street valley in Hangzhou as the research
object and carried out an in-depth study by using advanced ENVI-met numerical
simulation technology. The results show that although the canopy shape
and branch density of Picea abies have a relatively small impact on the air
temperature and relative humidity of the street, its unique tree structure shows
a significant effect in regulating the wind speed of the street. The canopy of
Picea abies guides the wind direction, resulting in a more even distribution of
wind speed in the street, which helps to improve the ventilation of the street
and enhances the thermal comfort of pedestrians. In addition, the study also
found that the tree structure of Picea abies performed well in reducing the mean
radiant temperature (MRT) of the street. Mean Radiant Temperature (MRT) is
an important measure of environmental thermal comfort, which reflects the
combined effect of the environment on human thermal sensations. In the late
afternoon, when the solar radiation is strong and the temperature is rising, the
tree structure of Picea abies can effectively reduce the mean radiant temperature
of the street by up to 13 ℃. This finding not only reveals the great potential of
Picea abies in mitigating the urban heat island effect and enhancing the thermal
comfort of pedestrians, but also provides a valuable reference for the planning,
design, and pruning management of urban roadway greening. In summary, as a
street tree, the unique tree structure of Picea abies plays an irreplaceable role in
improving the microclimate of urban streets and enhancing the thermal comfort
of pedestrians. In the future, in the planning, design, and pruning management
of urban road greening, the ecological advantages of Picea abies should be fully
considered, and tree species should be allocated scientifically and reasonably,
to create a more livable and comfortable urban environment, so that urban
residents can also enjoy the gifts of nature in the busy urban life. |
| Key words: landscape architecture street canyon Platanus sp. tree structure thermal comfort |
