近15年北京夏季城市热岛特征及其演变

根据北京地区20个地面气象观测台站1990-2004年7月的气温资料，分析了最近15年来北京夏季城市热岛的最新特征和变化趋势，也分析了城市热岛与气温，城郊地表温度差与地表温度，气温和地表温度间的关系。结果表明：北京夏季夜间出现了强热岛，郊区城市也出现了热岛现象，但白天城市热岛相对夜间不明显。夜间城市热岛强度呈逐年增强趋势，但白天这种趋势不明显。夜间城市热岛与气温呈正相关，气温高的年份，城市热岛强度相对也大；夜间城郊地表温差与地表温度呈正相关，地表温度越高，城郊地表温差越大；夜间，气温与地表温度呈正相关，气温越高，地表温度也高。白天，这些相关相对夜间来说不那么明显。研究成果对北京城市发展规划和高温灾害的防治有一定的科学参考价值。

Characteristics and Variations of Urban Heat Island Effect in Beijing for Last 15 years

Based on the data of 20 meteorological stations from 1990 to 2004 in Beijing, the characteristics and the variations of the urban heat island effect over Beijing are analyzed, and the relationship among the air temperature, the urban heat island effect, the ground temperature and the urban-rural ground temperature difference are also analyzed. The results show that strong UHI occurred in the night, but in the daytime UHI is not obvious. As a whole, UHI intensify year by year in the night, but in the daytime it is not obvious. In the night, the higher the surface temperature is, the stronger UHI becomes, and the greater the difference in urban-rural ground temperature becomes, the higher the ground temperature is, But in the daytime, all these relations are not so obvious as those in the night. The results can be used as scientific references to the development planning of Beijing city and the protection from high air temperature disasters of Beijing city.