天津城市扩张及其微气候特征演化研究——基于城市热环境的角度

Urban expansion of Tianjin and the micro climate characteristics evolution——Based on the urban thermal environment perspective

以快速城镇化进程下的典型区域天津市为例,以Landsat/TM和ETM+为主要数据源,采用辐射传输方程法反演地表温度,并进行各时期LST数据的标准化处理,分析建设用地扩张与微气候演化响应特征,并对微气候相关指数进行了探讨。结果表明,1992-2013年间,天津市建设用地出现了快速扩张趋势,其快速扩张期主要集中于2006年以后。微气候时空演化方面,热岛变化与建设用地扩张显著相关(相关系数达0.99)。温度等级上升区域方面,由1999年之前的塘沽区周边不断扩大至市辖区及周边环城四区(2006年),呈组团式分布特征,转变至2013年的市辖区以降温斑块为主,而快速升温斑块集中在东丽区、北辰区和塘沽区北侧。相对热岛效应指数呈现为由慢到快而后减缓的趋势,与建设用地扩张保持一致,热贡献指数在2006年之前与相对热岛效应指数变化保持一致,以后增幅开始减缓,冷贡献指数随旧城更新和大范围绿地建设而快速增加。

In this research,the typical area of Tianjin city which is under the rapid urbanization process was taken the example,the radiation transmission equation method was used to retrieve the land surface temperature,and the standard treatment of LST data of each period was conducted,the Landsat / TM and ETM ＋ were used as the main data source to analyze the construction land expansion and the micro climate change response characteristics,and the related indices of the micro climate were discussed. The results showed that during 1992- 2013,there had been a rapid expansion of construction land in Tianjin city,which was mainly occurred after 2006. As for the micro climate evolution,heat island variation was consistent with the construction land expansion. The temperature rate rising region expanded to the city and the four surrounding district of the city in 2006 from the Tanggu surrounding area before 1999,which was a group distribution; In 2013 the city core area was mainly formed by cool patches,but the rapid heating plaques concentrated on the north side of Dongli District,Beichen district and Tanggu district. The Relative heat island effect index presented from slow to fast and slow down,the heat contribution index before 2006 was consistent with the relative heat island effect index and then began to slow down,which was the same trend with the construction land expansion,and the cold contribution index increased rapidly with the old city renewal and large green space construction.