呼和浩特市城市空间扩展的热岛效应研究

STUDY ON THE HEAT ISLAND EFFECT OF URBAN SPATIAL EXPANSION IN HOHHOT

本文以呼和浩特市区为研究对象,选取1987年、1990年、2001年、2010年和2016年共5期的影像作为数据源。进行不同土地利用类型分类,采用单窗算法反演出地表温度,对比各土地利用类型之间的地表温度和对热环境的影响程度,并进一步分析城市空间扩展与热岛效应之间的关系。得出各土地利用类型的地表温度具有明显差异,建设用地和未利用土地温度高,耕地温度最低。从各土地利用类型对热环境影响程度来看,建设用地和耕地的热效应贡献度较大,其次是未利用地、水域和林地,草地贡献度最小。1987—2016年热岛中心迁移方向与城市重心迁移方向一致,表明城市扩展与热岛效应扩散趋势具有空间一致性。

Taking Hohhot city as the research object,this paper selects the images of 1987,1990,2001,2010 and 2016 as the data sources. Different land use types were classified. The single window algorithm was used to reverse the surface temperature. The land surface temperature and the impact on the thermal environment between different land use types were compared,and the relationship between urban expansion and heat island effect was further analyzed. It is found that the surface temperature of each land use type has obvious difference. The temperature of the construction land and the unused land is high,and the temperature of the cultivated land is the lowest. From the land use type to the thermal environment impact degree,the construction land and the cultivated land heat effect contribution is bigger,next is the unused land,the water area and the forest land,the grassland contribution is smallest.The migration direction of the center of the 1987—2016 year heat island is consistent with the direction of urban center of gravity migration,which shows that the trend of urban expansion and the diffusion trend of the heat island effect is consistent with space.