成都平原中等城市的热岛效应动态特征对比研究

Comparison on Dynamic Characteristics of Urban Heat Island Effects in Medium-Sized Cities in Chengdu Plain

城市热岛效应是当前城市气候与城市生态环境的研究热点。研究使用Landsat TM/ETM+遥感影像获取城市建成区信息和反演亮度温度,进而评价成都平原6个中等城市的热岛强度、热岛发育程度以及空间动态演变特征。研究发现,在"评价初期→评价中期→评价末期"过程中,成都平原6个中等城市的热岛强度前期增强、后期减弱;城市旧城区的热岛规模普遍减小,这说明,旧城区热环境有所改善,而城市扩展区的热岛规模普遍增大,是因城市扩展明显改变了地表自然环境,导致热岛效应出现,这与城市化进程的内在规律基本一致。绵阳等城市的研究成果表明,即使城市规模扩大,只要城市规划科学合理,并注重城市生态环境的保护,城市热岛效应也能得到有效缓解。

At present , research about Urban Heat Island Effects （ UHI） is a hot issue in urban climate and urban ecological environ-ment.This research obtained brightness temperature and urban information using remote sensing data of Landsat TM /ETM＋, and re-searched intensity , development degree , spatial structure and dynamic evolution of UHI of six medium -sized cities in Chengdu Plain . This research found that urbanization is the internal driving force leading to UHI .In the initial stage→interim stage→final stage, the overall heat island intensity trends in various cities in Chengdu Plain showed early enhanced and weakened late .The heat island size in the old town generally reduced , which indicated that the thermal environment has improved for the majority of the city ＆#39;s old town. The size of the heat island in urban expansion area generally increased , because urban expansion significantly changed the natural en-vironment , which leading to the heat island effect phenomenon .These research results are consistent with of urbanization inherent laws.Research results in Mianyang City also proved that , even if the urban scale expands , the urban heat island effect can be effec-tively alleviated, if urban plan is scientific and reasonable , and attached importance to protecting urban environment .