常青道路景观配置对交通噪声的衰减效果

选取重庆市主城区常见的3种道路景观植物——石楠(阔叶类植物)、小叶黄杨(中等叶子类植物)和雪松(针叶类植物),研究常青道路植物对交通噪声的衰减效果。结果表明:(1)在相同排列条件下,3种植物的降噪能力依次为石楠>小叶黄杨>雪松。对单一植物种,植物间交叉排列的绿化带对交通噪声的衰减效果比平行排列好。(2)不同种类植物对噪声的插入损失峰值所处的频段不同。针叶类植物对低频(<500Hz)噪声有很好的衰减效果,阔叶类植物对高频(>2 000Hz)噪声有很好的衰减效果,中等叶子类植物对中频(500～2 000Hz)噪声有很好的衰减效果。(3)选择针叶类植物和较大冠幅的阔叶类植物搭配种植,如雪松和石楠,可有效地提高绿化带对各频段的交通噪声的吸收能力。

The traffic noise attenuation provided by the collocation of the evergreen road landscape plants

Three kinds of road landscape plant,photinia serrulata(broad-leaved shrubs),lobular(medium-leaved shrubs) and deodar(coniferous shrub) were planted in green belt to investigate the performance of these evergreen road landscape plant for traffic noise attenuation.It has been discovered that noise reduction ability of the 3 plants followed the order of photinia serrulata> lobular> deodar,compared with the abreast arrangement,the crossing arrangement of the green belt has a good effect on the noise reduction.Different types of plants had obvious difference in noise-reduction spectrum between: deodar was specifically efficient to the low frequency(<500 Hz) noise attenuation,photinia serrulata had good performance for high frequency(>2 000 Hz) noise attenuation,the lobular was good at absorbing the medium frequency noise(500-2 000 Hz).Meanwhile,noise attenuation provided by plants-collocation was also studied.The results showed that the traffic noise can be effectively reduced through planting low branch coniferous plants and the big crown breadth of broad-leaved plants with narrow collocation-distance.