北京市冬季不同景观下垫面温湿度变化特征

Dynamicss of temperature and humidity in underlaying surface of different landscape type in winter in Beijing City,China

城市热场空间分布和动态演变受城市下垫面特征影响较大,基于实验观测数据,对北京市冬季不同景观类型下垫面的温湿度变化规律、特征进行了分析与探讨。2007年12月至2008年2月,选取北京市5类景观区域的4种不同下垫面,进行温、湿度等气象因子进行10h同步观测,分析不同景观区域的下垫面温湿度变化特征。结果表明:(1)北京市不同景观区域的温度呈乡村<水域<绿地<居住区<商业区的变化趋势,湿度呈相反的趋势。(2)在白昼期间,以郊区作为对照,四种城市用地在14:00的温、湿度差异均达极显著水平。商业区与郊区的最大温、湿度差值分别为6.3℃和24.2%,居住区的最大温、湿度差值为5.9℃和25.9%。(3)5个观测点的4种下垫面的日间气温呈水体<绿地<建筑物空间<道路的变化趋势,湿度呈相反的趋势;与道路、建筑物空间比较,绿地和水体空间白昼期间有明显的降温增湿效应。研究为减缓人类活动对城市气候的影响、减缓冬季热岛效应,为城市生态规划、环境治理及绿化建设提供基础依据。

Based on the field observation, the dynamics of temperature and humidity at underlying surface in Beijing City and their causes were analyzed. In order to identify the spatial distribution of heat and humidity in different urban landscapes and to evaluate their influences on the urban environment quality, 5 sites including Xidan, the commercial center of Beijing district, Mudanyuan, the residential area, Kunming Lake in Summer Palace, the water body, Chaoyang park, the urban green space and Wenquan Village, the suburb of Beijing were investigated from December, 2007 to February, 2008. The temperature and humidity at underlying surfaces, such as road, green space, water body and building space in these 5 sites were monitored simultaneously in 10 h period. The results indicate： （1） the temperatures of underlying surfaces in different landscapes were in the order of the suburb 〈 the water body 〈 the green space 〈 the residential area 〈 the commercial center, while the humidities of underlying surfaces were in the opposite order. （2） Taken the suburb village as a control, the different intensities of temperature and relative humidity at 14：00 were different significantly at 0. 01 level in four types urban land. Both the commercial center and the residential area had the urban heat island and urban dry island effect obviously. The biggest different intensities of temperature and humidity between commercial center and suburb were 6.3℃ and 24.2% respectively, and those in the residential area and suburb arrived at 5.9℃ and 25.9%. （3） The daytime temperature at each sampling site varied with different underlying surfaces in the order of the water body 〈 the green space 〈 the building 〈 the cement road, while daytime humidities at each sampling sitefall in the opposite order. Compared with the cement road surface, the building, green space and water body can decrease temperature and increase humidity. The results in this study may provide sound basis for urban ecological planning, environment improvement and afforestation management.