基于遥感分析土地利用变化对武汉城市热岛的影响

Analysis on the effect of land use changes on urban heat island in Wuhan based on remote sensing

城市热岛效应与城市化和土地利用变化密切相关.不透水面的扩张极大地改变了城市下垫面的热力学性质,这是造成城市热岛效应的主要原因.利用Landsat 7ETM+和HJ-1A卫星多光谱遥感数据,通过人工解译获得2002年和2012年武汉市土地利用情况,同时利用武汉同期的MODIS合成地表温度产品对城市热岛强度进行了分级,进而对城市热岛与土地利用的时空变化情况进行分析,揭示了二者之间的关系.结果显示,武汉市城市热岛的扩张表现为中高强度的城市热岛以各主城区为中心向外围延伸,并且有逐渐连接成片的趋势,这与城市化扩张的特征基本相同.建设用地的不断向外延伸是造成武汉城市热岛不断增强的主要原因.

Urban heat island effect is closely related to urbanization and land use changes.The expansion of urban impervious surface has greatly changed the thermodynamic properties of the underlying surface,which is a major cause of urban heat island effect.The authors obtained the land use data in Wuhan city in 2002 and 2012from Landsat 7ETM＋and HJ-1Asatellite multispectral remote sensing through artificial interpretation,and graded the urban heat island intensity by using the land surface temperature product obtained from MODIS,then analyzed the temporal-spatial change of urban heat island and land use changes and revealed their relationship.The results indicate that：1）the urban heat island effect in Wuhan city is of medium and high intensity,with its intensity highest in the downtown areas and declining to the periphery of each district and showing a tendency of connecting together,showing the same expansion pattern with urban areas;2）generally,urban heat island in Wuhan city is intensified by the expansion of urban construction land.