摘要
为了缓解长沙热岛效应的技术措施的制定,利用调查试验等基本数据,对长沙市热岛形成原因进行分析。结果表明:长沙城市热岛强度随建城区面积的扩大而加强,热岛效应影响的范围和向外扩展的趋势与城市建城区的轮廓及城市向外发展的趋势相一致;长沙城区内部结构特征和下垫面的热性质为城市热岛的形成奠定了基础;城区人为热源增加,增加了城区大气中的热量,促进城市热岛形成;排放的大气污染物和粉尘烟尘,若以"尘罩"或"气罩"的形式覆盖在长沙城区的低空层,阻挡城区地面长波辐射的散发,反过来增加大气对地面的长波辐射,有利热岛形成;长沙城市热岛一般出现在晴朗、无风(或微风),大气层结稳定,空气湍流运动较弱的天气条件下,若空气垂直运动剧烈,或降雨持续时长,降水量大,或地面风速超过4m/s的天气下,长沙城区不存在热岛现象。长沙城市热岛出现与否,天气气候条件起着重要的作用。
In order to develop the technical measures to alleviate the heat island effects in Changsha City,data set collected with method of test and investigation was analyzed the causes of heat island effects in urban area of Changsha City.The results showed that：urban heat island effect intensity was enhanced with the construction of the expansion of urban areas,and the scope and expansion trend of heat island effect was consistent with construction and development of urban areas;internal structure within the urban and urban surface characteristics of thermal properties was the basic foundation of urban heat island effects;artificially increasing the urban heat,which increased the urban heat in the atmosphere,promoted the formation of urban heat island effect;emissions of air pollutants and dust,adopting the ＇ dust cover ＇ or ＇ hood ＇ in the form of low coverage layer in atmosphere air,enabled the heat island effect through blocking long-wave radiation from the earth surface and,in turn,increasing the atmospheric long-wave radiation to the ground;weather and climate conditions played an important role in the presence of Changsha urban heat island effects.Changsha urban heat island effect generally happened in the conditions of sunny,no wind （or breeze）,stable atmospheric stratification,and weak air turbulence.On the contrast,the heat island phenomenon of Changsha City did not happen under weather conditions of severe vertical movement of air,or duration of rainfall,precipitation,or earth surface wind speed over 4 m/s.
出处
《中国农学通报》
CSCD
2012年第11期295-300,共6页
Chinese Agricultural Science Bulletin
基金
湖南省自然科学基金项目"城市森林减缓城市热岛效应的机理研究"(09JJ3031)
关键词
热岛效应
热岛强度
大气污染
人类活动
气候变化
urban heat island effects
heat island intensity
atmospheric pollution
human activities
climate change
