兰州城市热岛效应特征及其影响因子研究

Characteristics of Urban Heat Island Effect and Its Influencing Factors in Lanzhou

利用1958～2003年兰州及临近两个乡村气象站气温资料,研究了兰州城市热岛效应特征和导致热岛效应季节差异及其年代际变化趋势的主要气象因子.结果表明:近40多年来,兰州城市热岛效应一直呈增强趋势,热岛效应在冬季尤为显著;在日变化中以02:00热岛效应最为明显,而14:00效应较小.冬季逆温层、夏季城市下垫面对热岛效应的季节差异影响较大.城市发展导致热岛效应增强,而部分气象要素的年代际异常加剧了热岛效应.

The characteristics of Lanzhou urban heat island effect and the major meteorologieal factors resulting in the seasonal difference and the inter-decade change trend of heat island effect were analyzed by using temperature data from 1958 to 2003 of Lanzhou and two rural observation stations near Lanzhou. The results indicate that urban island heat effect in Lanzhou strengthened increasingly in the recent 40 years, and the intensity is greater in winter; as for daily variation, the heat island effect at 02：00 is most obvious, but that at 14.00 was less obvious. The winter inversion layer and the charaeteristics of the urban underlying surface in summer are the main factors leading to seasonal difference of heat island effect. The urban development resulted in the increasing heat island effect, and the abnormality of some meteorological factors aggravated the heat island effect in Lanzhou.