兰州中心城区用地扩展及其热岛响应的遥感分析

Urban expansion and its heat island response in Lanzhou City based on remote sensing analysis

以兰州中心城区为研究区,以1978、1993、2001和2010年的Landsat MSS/TM/ETM+影像为数据源,采用NDBI-SAVI指数相结合的方法,提取建设用地信息,利用热红外波段的单窗算法反演城市地表温度。结合城市热岛比例指数和地表温度分级,定量研究城镇用地扩张对城市热环境的影响。结果表明:兰州中心城区建设用地在1978—2010年的30余年间面积由87.47km2增加到172.61km2,增幅近1倍。城市扩展与热岛扩展趋势具有空间一致性,在城市扩张的同时,城区地表温度逐渐上升,城市热岛面积不断扩大。

This paper quantitatively analyzed the effects of urban expansion on city thermal environment, taking the urban area of Lanzhou City as a case, and based on the 1978, 1993, 2001 and 2010 Landsat/TM and ETM＋ images. The information of urban construction land was extrac- ted by using NDBI-NDVI index, and the land surface temperature was retrieved via mono-window algorithm, with the urban heat-island ratio index and the land surface temperature grade maps built. In 1978-2010, the construction land in the central area of Lanzhou City increased from 87.47 km2 to 172.61 km2, and the urban expansion had a spatial consistency with the urban heat island expansion. At the same time of urban expansion, the urban surface temperature increased gradually, and the heat island area had an increasing expansion.