中文摘要：

本文利用LANDSAT-8数据计算距离加权不透水面聚集密度,以城市聚类算法提取北京市主要城建区范围。并用2005-2014年MODIS 8天合成地表温度产品,以主要城建区面积150%的周边区域作为边缘区,计算城建区与边缘区平均温度差值为热岛强度;分析北京市主要城建区热岛强度年内时序变化;依据地表温度与当月平均热岛强度对热岛强度进行等级划分,统计不同热岛强度等级出现频率,分析其空间分布特征及与不透水面聚集密度的相关性。结果表明：（1）年内1-12月热岛强度随边缘区平均温度变化显示较好的规律性,白天为逆时针分布,夜间为顺时针分布;（2）白天热岛强度等级以2、3级为主,春、夏季中南部为三级热岛强度高发区;夜间呈现由外围向中心的＂环状递增＂特征,高等级热岛强度出现的频率由外围向中心不断递增;（3）不透水面聚集密度对白天不同等级热岛强度出现频率影响显著,1-4级热岛强度出现频率,随不透水面聚集密度增加而增加,不透水面聚集密度达到50%后的影响趋于减弱。

英文摘要：

To study the urban heat island（UHI） effect of Beijing with long time series data, MODIS 8-day land surface temperature product from 2005 to 2014 is used to obtain the information about Beijing heat island, and LANDSAT-8 data on October 2, 2014 is used to get the distribution of Beijing imperious surface. The distanceweighted imperious surface cohesion density is calculated, Beijing ＇ s main urban construction area is extracted based on city cluster algorithm, and a boundary is determined around the main urban construction area with an area of approximately 150% to the main urban construction area. We calculate the mean temperature difference between the main urban construction area and the boundary area, and regard it as UHI intensity. Then, we analyze the intra annual changes of UHI intensity, rank UHI intensity according to the land surface temperature and the month average of UHI intensity, perform statistical analysis on the frequency of UHI intensity level, and analyze the spatial distribution of UHI intensity level and its correlation with urban construction aggregate density. The results show that：（1） the dependency of UHI intensity on the boundary temperature showing a regulated pattern on the intra annual variations of UHI effect： counterclockwise distribution during the day and clockwise distribution at night;（2） in the daytime, the spatial distribution of UHI intensity level frequency appears to be level-2 and level-3, and the south-central high incidence area is featured by the level-3 heat island intensity during spring and summer; while at night, it has little correlation with construction cohesion density,but shows a cyclic characteristic increasing from the periphery to the center;（3） the imperious surface cohesion density make a notable effect on the frequency of different UHI level during the day with a positive correlation,while the effect tends to weaken when the imperious surface cohesion density is higher than 50%.