Urban green space is an effective way to alleviate urban heat island effect. It plays a very important role in temperature dropping and humidifying. In this paper, three kinds of green space including square with tree layer(greening square) and without tree layer (none-greening square) also lawn were selected in Wan-Fang-Ting Park to study on effects of greening space on temperature, humidity and human comfort. The air temperature and relative humidity were measured once every two hours from 8:00 to 18:00 every day and continuously seven days in July 2006.
The results indicate that greening square has the lowest temperature and highest humidity during the middle of the day with high air temperature and the lawn has the lowest temperature and highest humidity in the late afternoon.
Compared with none-greening square, the greening square can decrease temperature 0.3-3.3℃ with the average of 1.9℃, and increase the humidity from 2.1%-4.7%, with the average of 3.2%.The greening square has lowest daily maximum temperature and can reduce the duration of high temperature for the maximum eight hours. The differences of air temperature and humidity between greening square and none-greening square reach significance level (p<0.01) by Duncan′s multiple comparison.
It can be concluded that the greening square has the best effects on the adjustment of urban microclimate and human weu-being, and can be important for outdoor activities.