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.