南京市四种下垫面气温日变化规律及城市热岛效应  

The diurnal change of air temperature in four types of land cover and urban heat island effect in Nanjing, China

作　　者：黄良美[1] 黄海霞[2] 项东云[1] 朱积余[1] 李建龙[2] 

机构地区：[1]广西林业科学研究院,广西南宁530001 [2]南京大学生命科学院,江苏南京210093

出　　处：《生态环境》2007年第5期1411-1420,共10页Ecology and Environmnet

基　　金：国家自然科学基金项目(30070432);广西林科院青年科技基金项目(2005-f-02)

摘　　要：为了监测城市热岛特征、热场空间分布及综合评价城市环境质量,探讨消减城市热岛效应对策,2005年7—9月期间,通过对南京市的中心城区夫子庙、城市湖泊玄武湖、城市森林紫金山、城市郊区浦口四个观测点选取水泥地、草地、林地和水体四种下垫面进行温度、湿度、风速等气象因子的24 h同步观测,结果表明,（1）四个观测点的四种下垫面白天气温呈林地〈水体〈草地〈水泥地的变化趋势,夜晚则是相反,但草地的温度最低;与水泥地比较,其他3种下垫面白昼期有明显的降温效应,均幅度为0.2-2.9℃,而夜晚林地与水体有轻微的保暖效应,晴好无风天气时这种效应更明显。（2）南京市的热岛强度平均为0.5-3.5℃,凌晨3：00左右热岛强度较大且平稳,当日出后热岛强度减小,但在中午12：00左右有一个明显回升,然后下降,至傍晚18：00-21：00,热岛强度有个强烈提升的高峰。（3）利用各观测点温度的时间标准差、空间标准差及时空数据正规化的标准差定量与定性的揭示了城市景观与城市下垫面对城市热岛效应变化的影响机理。（4）不同观测点舒适度指数表明观测期间人们对温度、湿度和风速日变化的综合生理感觉是暑热到较舒适间的变化过程,紫金山和浦口有时给人舒适的感觉。基于实验观测数据,对南京市不同下垫面的温度日变化规律、热岛强度特征、舒适度指数以及相关成因机理进行了全面分析与探讨,为城市生态建设、城市规则、城市环境治理及城市绿化建设提供重要的理论参考。Rapid changes in temperature generated by the urban landscape influence the comfort and health of inhabitants as well as energy consumption and air quality, therefore, it is important to understand the causes of air temperature variation in different land use areas. In this paper, four types of land cover, namely urban bare concrete cover, urban woods or the shade of trees, urban water areas and urban lawn were selected to study their microclimate characteristics, and the urban heat island （UHl） was also analyzed using air temperature and relative humidity data measured at four fixed observational spots in Nanjing, China, from July to September, 2005. Dry and wet bulb temperature data were obtained by whirling psychrometers, and wind speed data by cup anemometers. The results showed that： （1） The microclimate of the four types of land cover had significant differences among different observation sites. In general, the air temperature of these land covers complied with the order during daytime： urban bare terra 〉 urban lawn 〉 urban water areas 〉 urban woods or the shade of trees, with reversed order during night when the temperatures of the lawn became the lowest. Compared with the bare terra or cement cover, the other three types showed the effect of dropping air temperature ranging between about 0.2 - 2.9 ℃. There were some instantaneously dynamic characteristics in detailed temporal series among these four covers in different observational sites. Therefore, a marked heterogeneity in a smaller ground cover scale could be detected from the microclimatic spatial pattern. （2） The UHI effect could be detected obviously by the air temperature difference between urban and surrounding areas. The average UHI intensity during the monitoring period was between 0.5 - 3.5 ℃; however, there was also significant day-to-day variability. A strong UHI effect usually occurred around midnight; while about 2-3 h after sunrise, the UHl began to decrease till midday time; and during 13：00 - 15：00, the UH

关 键 词：城市下垫面 热岛强度日变化 成因与机理分析 舒适度指数 

分 类 号：X16[环境科学与工程—环境科学]