中国主要城市大气与地表热岛效应的对比研究

A comparative study of atmospheric and surface urban heat island effects in China's major cities

伴随着我国城市化的飞速发展,城市热岛效应日益严峻,对生态环境和人类健康的危害也逐渐加强。文中以我国84个主要城市为例,利用气象观测和遥感数据基于城乡气象站点温度差异,对比分析了2007—2017年我国大气与地表城市热岛效应的差异,并得出以下主要结论:2007—2017年白天和夜晚平均大气热岛强度分别为0.37℃和1.15℃,变化趋势分别为﹣0.10℃/(10 a)和﹣0.15℃/(10 a);平均地表热岛强度分别达1.08℃和1.32℃,变化趋势分别为﹣0.03℃/(10a)和0.13℃/(10a)。大气热岛效应与地表热岛效应在强度、空间分布、日变化、季节变化和年际变化趋势方面均存在明显差异。此外,发现现有的国家气象站点观测数据存在低估城市热岛效应的风险。本文结果证实了我国大气热岛效应的极大时空异质性及其与地表热岛效应时空格局的巨大差异,强调了从大尺度开展多方法集成研究,进而全面把握城市热岛效应演变规律的重要性。未来需加强对大气热岛效应的高密度观测与驱动机制的研究。

With rapid urbanization in China,urban heat island effect is becoming increasingly severe,and the harm to the ecological environment and human health is also gradually strengthened.Taking 84 major cities in China as an example,the differences between the atmospheric and surface urban heat island effect were compared and analyzed by using meteorological observation and remote sensing data from 2007 to 2017.The main results are as follows.The average atmospheric heat island intensity during the day and night from 2007 to 2017 is 0.37℃ and 1.15℃ respectively,and the change trend was ﹣0.10℃/(10 a) and ﹣0.15℃/(10 a)respectively.The average surface heat island intensity reached 1.08℃ and 1.32℃ respectively,and the change trend was ﹣0.03℃/(10 a) and 0.13℃/(10 a) respectively.There were obvious differences between atmospheric and surface urban heat island effect in intensity,spatial distribution,diurnal variation,seasonal variation and interannual variation trend.In addition,it was found that the existing national meteorological station observation data have the risk of underestimating the urban heat island effect.The results of this paper confirm the great temporal and spatial heterogeneity of atmospheric urban heat island effect in China and its difference from surface urban heat island effect in the temporal and spatial pattern,and emphasize the importance of carrying out multimethod integration research on a large scale,so as to comprehensively grasp the evolution law of urban heat island effect.In the future,it is necessary to strengthen the research on the high-density observation and driving mechanism of atmospheric urban heat island effect.