长沙市城区热岛时间分布特征分析

为了研究长沙市城区的热岛特征及变化规律，利用长沙市城区和郊区气象观测站的观测数据，通过统计分析，对长沙市城区热岛强度时间分布特征进行了研究。结果表明：（1）21年间（1988-2008年）长沙市平均热岛强度为0.92℃，年均变化在0.76~1.46℃之间。（2）热岛强度的季节变化规律是秋、冬季强，春、夏季弱。（3）热岛强度日变化表现为夜间比白天强；夏季整天存在热岛现象，其他季节表现为快速形成和快速消失的现象。结论表明：长沙市热岛强度的年变化与城市建设的进程相一致；近20年来，长沙市城区和郊区的气温同步增高，同时热岛强度越来越大，说明全球气候变暖加剧了城市热岛效应，同时也是人类活动结果的影响。

Distribution Characteristics of Urban Heat Island in Changsha City

The authors studied distribution characteristics of time on intensity of urban heat island in Changsha City. The authors used the meteorological observation data from observation stations of the urban and suburban in Changsha City. By statistical analysis, the results showed that： （1） the annual average heat island intensity was 0.92℃, annual average changed between the 0.76-1.46℃ during the last 21 years from 1988 to 2008. （2） The seasonal variation of intensity of urban heat island manifested as that autumn was stronger than winter than spring than summer. （3） The intensity of urban heat island in nighttime was stronger than in daytime during summer season. The conclusion showed that： annual variation of intensity of urban heat island was consistent with the processing of urban construction. The temperatures of urban and suburban increased simultaneously, and the intensity of urban heat island had been enhancing year by year in the nearly 20 years, the reason were global warming and the impact of human activities.