基于多源数据的城市热岛效应研究——以石家庄地区为例

Study of Urban Heat Island Based on Multi-Source Data——By the Example of the Shijiazhuang Area

以石家庄地区为研究对象,选取地面气象观测站数据、区域自动站数据、MODIS 1B以及Landsat7 ETM+卫星遥感影像数据作为主要数据源,从气温和地表温度两个角度考虑,分析城市化进程对城市热岛效应的影响,城市热岛的时间变化规律以及空间分布规律等。研究结果表明:(1)石家庄城市热岛强度随时间逐年增加且呈继续上升趋势,与城市化进程呈同步变化趋势;(2)采用同一时次气温和地表温度资料分别研究石家庄城市热岛空间分布特征,发现夏、秋季白天和四季晚上石家庄城市热岛效应明显,春、冬季白天有时出现"冷岛"效应;(3)与白天相比,在晚上气温和地表温度两者的相关性较好,其相关系数可达0.80;(4)选用Landsat7 ETM+高分辨率卫星遥感影像数据研究不同土地覆盖类型对城市热岛的影响,发现地表温度随着植被指数NDVI的增大而减小,两者之间呈现很好的负相关性,R^2=0.72。

The surface meteorological station data, regional automatic station data, MODIS 1B data and Landsat7 ETM＋ satellite remote sensing data are used to study urban heat island in Shijiazhuang area. Temperature and land surface temperature data are used to study the impact of the urbanization on urban heat island, the temporal and spatial distribution of the urban heat island, etc. The result showed that： （1） The urban heat island in Shijiazhuang is increasing year by year, sharing the synchronous tendency with urbanization; （2） Temperature and land surface temperature data at the same time are used to study the spatial distribution of the urban heat island, which shows that the days of summer and autumn, and the nights of whole year have remarkable urban heat island （UHI） effect, but the cool island phenomenon sometimes appears in the spring day and the winter day; （3） The night temperature and land surface temperature （LST） were both correlated, the correlation coefficient is 0.80; （4） Landsat7 ETM＋ data are used to study the effect of the different land cover categories on UHI, we found that NDVI and LST are negatively correlated. The smaller NDVI is, the higher LST is, and their negative correlation coefficientR^2is 0.72.