不同地被类型对城市热环境的影响研究

Study on reducing effect of different urban landscapes on urban temperature

近些年来我国城市热环境急速恶化,特别是2013年我国南方多地出现突破历史极值的极端高温天气,严重影响了居民正常生活。本研究以深圳为例,运用气象站定点观测方法并首次引入运动样带观测方法对深圳市典型地被类型的气温进行监测、分析,探讨不同地被类型对城市热环境的影响。气象站定点监测实验从2011年6月至今,持续样带监测实验开始于2011年6月结束于2013年7月。本研究详细纪录了深圳市西丽大学城及其周边有典型地被类型的气温、太阳辐射、风向、风速等气象数据。根据不同城市景观分选出5种不同的典型城市地被类型:城市景观水、城中村、商业区、城市绿地、郊区。利用观测获得的具有高空间分辨度和高时间分辨度的实验数据对5种不同的地被类型进行分析比较,结果表明:5种不同城市景观的温度差异明显,商业区温度>城中村温度>城市景观水区域温度>城市绿地温度>郊区温度。城市绿化和景观水对城市热岛有明显的缓解作用,城市景观水可缓解城市热岛强度0.9℃,城市绿地可缓解城市热岛强度1.57℃。城市绿地的降温效果比城市景观水好,比城市温度的缓解效果强0.67℃。人类的周期性活动对区域城市热岛强度有明显的影响。一周时间内,商业区、城中村、城市景观水、城市绿地的城市热岛强度均呈"U"字形。周末四种地被类型的热岛强度比工作日要高,分别高出0.65℃、0.57℃、0.26℃、0.21℃。

Through continuous belt transect monitoring from June 2011 to July 2013 and fixed-point weather station monitoring from June 2011 to the present, we have recorded the temperature, sun radiation, wind direction, wind speed and other metrological data in detail at Xili University Town, Shenzhen, and other representative locations in its neighborhood. According to different ground covers, we have selected 5 different urban landscapes, including urban waterscape, village in the city, shopping center, urban greenness and suburb. According to the monitoring results, the periodical activities of human beings exert a significant effect on strength of the local urban heat islands. For different urban landscapes, the temperature of Saturday and Sunday is higher than that of working days from Monday to Friday. The temperature difference between the 5 different urban landscapes is significant, i.e. shopping center〉village in the city〉urban waterscape〉campus〉urban greenness〉suburb. At the same time, compared with shopping center, urban waterscape can reduce the strength of local urban heat island by about 0.9 ℃, and urban greenness by about 1.57 ℃.