上海城市街道峡谷道路绿化模式研究

街道峡谷在上海城市中普遍存在,街道峡谷中污染气体的扩散受到屋顶风向、风速、高宽比、峡谷两侧建筑物的对称性、高度分布和街区形状等因素的影响。文章对适合于不同街道峡谷形式的、较为典型的道路绿化模式进行了研究。结果表明,上海城市街道峡谷中的道路绿化模式可归纳为:梯级递进式、斑块复合式、疏朗开敞式、模纹花镜式和独立行道树式5种。当街道峡谷与主导风垂直:(1)街道峡谷的W/H>5且为平行型峡谷时,绿化模式应采用梯级递进式或疏朗开敞式;(2)街道峡谷的W/H为0.6～5且为平行型峡谷时,绿化模式在迎风侧采用流朗开敞式、背风侧采用模纹花镜式,或者两侧都采用模纹花镜式;(3)街道峡谷的W/H<0.6且为平行型峡谷时,绿化模式应采用模纹花镜式或独立行道树式;(4)街道峡谷的W/H<0.6且为递升型峡谷时,绿化模式在迎风侧采用斑块复合式或模纹花镜式,背风侧采用模纹花镜式或独立行道树式;(5)街道峡谷的W/H<0.6且为递降型峡谷时,绿化模式可采用模纹花镜式或独立行道树式;当街道峡谷与主风向平行:宽、高比大的街道绿化模式应采用梯级递进式或斑块复合式,当街道峡谷的高度是宽度的倍数时,道路绿化宜采用疏朗开敞式或独立行道树式。

Study on Road Afforestation Model of Street Canyon in Shanghai

Street canyon is popular in Shanghai urban, dispersion of air pollution of street canyon is effected by roof level, wind speed and direction, street canyons width/height ratio and symmetry, the shape and building heights distribution of blocks surrounding line sources. In according to design of street canyon road afforestation in current urban of Shanghai, it can be summarized as the following 5 afforestation models: increasing degrees model, multiple patches model, sparsity and opening model, modeling flowers model, and inde pendent street-tree model. The afforestation model of street canyon vertical to the main wind direction: (1) paralleling canyon with W/H > 5 of street canyon, increasing degrees model and sparsity and opening model can be adopted, (2) paralleling canyon with W/H from 0.6 to 5 of street canyon, sparsity and opening model can be adopted at windward side and modeling flowers model can be adopted at leeward side, or modeling flowers model can be adopted at two sides of street canyon; (3) paralleling canyon with W/H < 0.6 of street canyon, the model of modeling flowers and independent street-tree can be adopted at two sides of street canyon, (4) increasing canyon with W/H < 0.6 of street canyon, modeling flowers model and multiple patches model can be used at windward street canyon and modeling flowers model and independent street-tree model can be adopted at leeward side, (5) decreasing canyon with W/H<0.6 of street canyon, modeling flowers model and independent street-tree model can be adopted. The street canyon horizontal to main wind direction: (1) increasing degree afforestation and multiple patches model should be adopted, (2) simple model of road afforestation should be adopted.