目的 利用数值模拟不同绿化布局方案对居住区微气候的影响，以期获取最优绿化方案。方法 以广州某老旧小区为研究对象，选取典型湿热天气条件，对研究区的室外微气候要素进行测量；利用模拟软件ENVI-met构建实况数值模拟模型，将模拟结果与实测值进行对比分析，验证模型精度和质量；对研究区预设的3种绿化方案微气候特征进行模拟分析。结果 清理灌木后温度较现状平均升高0.1 ℃，湿度平均降低0.51%，可适当改善低处通风情况；去除乔木后温度升高近0.4 ℃，湿度降低1.18%，整体风速明显增大；屋顶简单式绿化具有一定的降温增湿效果，温度降低0.16 ℃，湿度增加1.17%，风速较现有绿况变化不大。结论 ENVI-met能够较好地预测温度和湿度的日变化趋势，能有效地评估老旧小区空间的营造与绿化改善效果。
Objective The effects of different landscape layout schemes on microclimate of residential area were numerically simulated to obtain the optimal scheme.Method Taking an old residential area in Guangzhou as the research site, we measured key characteristics of the outdoor microclimate under typical humid and hot weather condition. A numerical simulation model was built using ENVI-met software. The accuracy and quality of the model were validated by comparing the simulation results with the measured values. The microclimate characteristics of three landscape layout schemes were simulated and analyzed.Result Comparing with the current landscape condition, after clearing shrubs from the landscape layout, the mean temperature increased 0.1 ℃ and the mean humidity decreased 0.51%, and ventilation near the ground was moderately improved. After removing trees from the landscape layout, the mean temperature increased 0.4 ℃, the mean humidity increased 1.18%, and the overall wind speed evidently increased. After the roof was simply landscaped with green plants, the mean temperature decreased 0.16 ℃, the mean humidity increased 1.17%, and the wind speed did not obviously change.Conclusion ENVI-met model can be used to well predict the diurnal variation trend of temperature and humidity, to effectively evaluate the influence of landscape planning and improvement in old residential areas.