Public Park Green Belt Micrometeorology and Its Impact on Human Comfort Under Typical Summer Weather

To explore green land micrometeorology in public parks under typical summer weather (sunny, cloudy, and after raining) and its impact on human comfort, monitoring posts were set up at 8 selected typical recreation places in the Beijing Haidian Park. Results show that the park green belts significantly reduced air temperature, increased relative humidity, decreased wind speed, and improved human comfort. Weather is an important factor affecting significantly human comfort. Body comfort on green land lasted for 4-7 hours under a sunny or cloudy sky, 1-4 hours longer than on CK (lands other than green belt); and for 5-11 hours after raining. The impacts of green lands on temperature, humidity and wind varied significantly with the type of green land. Willow-locust forests were the most remarkable in reducing the integrated human comfort index of the three types of weather by 5.0%-5.4%; and lawns the least by only 0.4%-1.5%. The three types of weather, sunny, cloudy and after-raining reduced the temperature by 0.5-2.6, 0.7-2.7 and 0.6-2.0℃; increased the humidity by 2.2%-10%, 2.6%-10.25% and 1.1%-4.3%; and decreased wind speed by 16.7%-66.7%, 16.7%-66.7% and 22.2%-55.6%, respectively. So, under typical summer weather, 06:00-09:00 am is the most favorable time period for people to do outdoor activities; in sunny or cloudy days, people would feel uncomfortable after 10:00 am; and after raining people may have outdoor exercises or activities in these recreational spots after 17:00.