芜湖市城市热岛效应时空变化分析

Spatial-Temporal Variations Analysis of Wuhu Urban Heat Island Effect

目的利用2006年Lantsat7 ETM^+影像和2014年Lantsat8 TIRS影像作为数据源,对芜湖市城市热岛效应时空变化进行分析,探讨芜湖市城市热岛效应产生的原因。方法利用ENVI软件对芜湖市地表亮温进行反演,对地表亮温进行归一化处理,按照等差级数对结果进行密度分割,再结合芜湖市土地利用分类结果,对芜湖市城市热岛效应时空变化进行分析。结果结果表明,芜湖市城市热岛效应显著,热岛强度和范围都有所增加,极高温区分布较少,强热岛区主要分布在镜湖区和弋江区。从2006年到2014年,建筑物和裸地由镜湖区和弋江区逐渐扩展到新芜区,面积分别增加6.76%和7.26%,农田和林地分布在周边乡镇,面积分别减少2.25%和5.02%,水体面积减小0.12%;高温区由镜湖区和弋江区扩展到新芜区,面积增加33.41%;低温区主要分布在郊区,面积减少50.25%。结论不同土地利用类型对城市热岛效应影响差异性较大:建筑和裸地温度最高,其次是林地和农田,水体温度最低;而且土地利用面积的变化与热岛区面积变化趋势相同,土地利用变化是引起芜湖市热岛效应的主要因素。

ObjectiveBy using the lantsat7ETM+image in2006and the lantsat8TIRS image in2014as data sources,the spatial temporal variations of Wuhu urban heat island effect was analyzed and the causes of Wuhu urban heat island effect were discusced.MethodsThe surface bright temperature was inverted by the ENVI software,the surface bright temperature was normalized,and the surface bright temperature was classified by the arithmetic progression.And the spatial temporal variations of Wuhu urban heat island effect were analyzed by the land use classification results.ResultsThe results indicate that Wuhu urban heat island effect was significantly,the intensity and scope of Wuhu urban heat island effect had increased.However,the distribution in the extremely high temperature area is less.The strong heat island area is mainly distributed in the Jinghu area and Yijiang area.From2006to2016,the construction land and the bare land gradually extended from Jinghu district and Yijiang district to Xinwu District,the area of the construction land and the bare land increased by676%and726%respectively.The farmland and the forest land were distributed in the surrounding towns,he area of the farmland and the forest land decreased by225%and502%respectively.The water body area decreased012%.the high temperature zone gradually extended from Jinghu district and Yijiang district to Xinwu District,the area increased by3341%.The low temperature zone was distributed in the suburbs,the area decreased by5025%.ConclusionDifferent land use types have greater different impact on the urban heat island effect.The temperature of the building and bare land are the highest.Followed by the woodland and the farmland.The temperature of the water area is lowest.And the change tendency of land using area is the same as that of the urban heat island area,and the land use change is a major cause of Wuhu heat island effect.