地理科学 ›› 2014, Vol. 34 ›› Issue (3): 338-343.doi: 10.13249/j.cnki.sgs.2014.03.338

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基于地表能量平衡的城市热环境遥感研究——以石家庄市为例

肖捷颖(), 张倩, 王燕, 季娜, 李星   

  1. 河北科技大学环境科学与工程学院河北省污染防治生物技术实验室, 河北 石家庄 050018
  • 收稿日期:2013-02-04 修回日期:2013-06-10 出版日期:2014-03-10 发布日期:2013-11-18
  • 作者简介:

    作者简介:肖捷颖(1970-),女,河北涿州人,副教授,博士,主要从事环境遥感应用研究。E-mail: xiaojieying@gmail.com;xiaojieying@hebust.edu.cn

  • 基金资助:
    河北省自然科学基金项目(D2010000867)、河北省高校重点学科建设项目资助

Urban Surface Heat Flux Analysis Based on Remote Sensing: A Case Study of Shijiazhuang City

Jie-ying XIAO(), Qian ZHANG, Yan WANG, Na JI, Xing LI   

  1. Pollution Prevention Biotechnology Laboratory of Hebei Province, School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018, China
  • Received:2013-02-04 Revised:2013-06-10 Online:2014-03-10 Published:2013-11-18

摘要:

对石家庄市LandsatTM数据进行土地覆被分类,计算各土地覆被类型的能量平衡分量。找出感热、潜热、储热通量在下垫面的分配差异并分析下垫面面积比例与感热/净辐射的关系。发现密集不透水面感热单位面积能量达314.1 W/m2,49.9%的净辐射转换为感热。城市植被、水体净辐射的61.2%,65.9%变成潜热;感热/净辐射与城市植被和水体面积比例负相关,面积比例小于30%,感热/净辐射随之减少而快速增长;大于30%则随之增加缓慢降低。感热/净辐射与不透水面面积比显著正相关,可见,城市近地层温度升高主要由不透水面产生的感热交换引起。

关键词: 城市热环境, 感热通量, 潜热通量, 人为热

Abstract:

Urban heat island is a phenomenon with higher temperature in urban area than that in rural area. China has experienced unprecedented rapid urbanization since 1990s, urban heat island became complicated recently and attracted more attention. In order to understand formation mechanism of urban heat environment better, this study analyzed urban heat environment spatial pattern, from the view point of surface energy balance. Shijiazhuang City, with a history of only 100 years and population of 2.86 million, is the largest city of Hebei Province. We used a Land sat TM image recorded on Aug. 12, 2009 for analysis, including extraction of the information on land surface temperature, water index and impervious surface index. The land cover of study area was classified into high density impervious surface, low density impervious surface, urban vegetation, water body, agricultural vegetation and bare land by using decision tree method. Then net radiation, sensible heat flux, latent heat flux, storage heat flux and anthropogenic heat were simulated for investigating the impact of the energy balance to urban heat environment. At last, quantitative analysis on energy per unit area comparison, energy conversion among different underlying surfaces and correlation between energy and area percentage of different underlying surfaces were analyzed. Results show that high density impervious surface(17.9%), low density impervious surface (29.2%) and agricultural vegetation (26.0%) are major land cover types, and all underlying surfaces including urban vegetation (18.6%), water body (0.7%) and bare land (7.7%) play an important role in urban heat environment formation. We also found that the amount of sensible energy per unit area of high density impervious surface (314.1 W/m2) and low density impervious surface (262.4 W/m2) were higher than other underlying surfaces, and there were 49.9% and 42.9% of net radiation conversed to sensible heat. Anthropogenic heat generated from high density impervious surface is 41.3 W/m2. While the highest amount of latent energy per unit area occurred at water body (479.0 W/m2). In the city, there were 61.2% and 65.9% of net radiation conversed to latent heat from urban vegetation and water body, and it indicated that they cooled the city. Percentage of impervious surface is significant positively correlated with sensible heat flux/net radiation. QH/Q* will increase by 0.3%, along with 1% increasing of impervious surface. On the other hand, sensible heat flux/net radiation will increase rapidly along with urban vegetation and water body area percentage decreasing when it is less than 30%, while if it is more than 30%, QH/Q* with decrease slowly. In sum, urban heat environment is mainly caused by sensible heat exchange from impervious surface, while urban vegetation and water body can cool the city through latent energy.

Key words: urban heat environment, sensible heat flux, latent heat flux, anthropogenic heat

中图分类号: 

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