在夏季的高温季节对上海市21个居住区的130个绿地斑块的环境温度和相对湿度进行了测定,比较研究了不同绿地斑块的降温效果及其影响因素。结果表明,城市绿地斑块对周围环境具有明显的降温增湿作用,能明显改善人体的舒适度,绿地中心温度降低2.6℃、相对湿度增加8.3%、人体舒适度增加0.8。环境温度和相对湿度对绿地斑块的降温幅度有显著影响且环境温度的影响大于相对湿度;降温幅度与环境温度呈显著正相关(R=0.416)、与相对湿度呈显著负相关(R=0.460);随环境温度升高、相对湿度降低,绿地中心的降温幅度最大。在影响绿地斑块降温幅度的主要结构指标中,大乔木盖度的影响力最强,其次为小乔木盖度和灌木盖度,并随盖度增加,绿地尤其是绿地中心的降温效果越来越明显。绿地类型、遮阳程度及配置不同的树种对绿地斑块的降温幅度也有显著影响;大乔木绿地的降温幅度最大(2.8℃),其次为小乔木绿地(2.0℃),乔灌相间和灌草结合的绿地平均降温幅度分别仅为1.4℃和1.2℃;以雪松〔Cedrus deodara (Roxb.) G.Don〕和香樟〔Cinnamomum camphora (L.) Presl〕为优势树种的绿地斑块降温效果最明显,草坪的降温效果最差。从降温角度考虑,居住区的绿化应多采用以乔木为主、灌草为辅的绿地结构类型,尽量避免使用单一的草地绿化类型。 

The environment temperature and relative humidity at 130 green patches of 21 urban residential areas in Shanghai were investigated at high temperature weather in summer, and temperature drop range at different urban green patches and its influence factors were also researched. The results show that the urban green patch has an obvious effect on  falling temperature and increasing relative humidity to surrounding environment,  which can improve human comfort with a temperature falling of 2.6℃ , relative humidity increasing of 8.3% and human comfort increasing of 0.8 at the center of green space. The environment temperature and relative humidity have significant effects on temperature drop range of urban green patches, and the effect of environment temperature is higher than that of relative humidity. The temperature drop range has a significantly positive correlation with environment temperature(R= 0.416) and a significantly negative correlation with relative humidity (R= 0.460). With environment temperature rising and relative humidity decreasing, the temperature drop range at green space center is the biggest. Among the main structural indexes affecting temperature drop range of urban green patch, the influence of big arbor coverage is the strongest, followed by that of small arbor and shrub coverages, and with increasing of coverage, the effect of falling temperature become more and more obvious at the green space, especially at the center of green space. Also the green space type, shading state and tree species planted at urban green patches have significant effect on temperature drop range. The temperature drop range of green patches planted with big arbor is the highest (2.8℃), 2.0℃ with small arbor, and only1.4℃ and 1.2℃ with arbor-shrub and shrub-herb, respectively. Using Cedrus deodara(Roxb.) G.Don and Cinnamomum camphora (L.) Presl as dominant tree species at green patches, the effect of falling temperature is the most obvious, while that of lawn is the worst. It is suggested that for falling temperature, arbor should be used as dominant structure type and shrub-herb as subsidiary type, and single lawn green type is avoided as possible to use in green design at residential areas.