近30年北京气候舒适度城郊变化对比分析

Comparative Analysis of Urban and Rural Climate Comfortabilities in Beijing in Past 30 Years

利用北京市城郊20个气象观测站1981—2010年30年气象资料，计算了20个站点的逐日舒适度指数，并统计了北京城郊夏季最热舒适度、冬季最冷舒适度的年平均值以及炎热日数、酷热日数、寒冷日数和严寒日数，最终分析给出了北京舒适度的年际和空间变化特征以及城郊舒适度差异。结果表明：20世纪80年代，北京夏季最热舒适度在炎热标准以下，城郊差异不大；90年代至今增热趋势明显，炎热和酷热日数显著增多，特别是平原地区炎热和酷热日数分别增加到40天和8天，且炎热和酷热日数空间分布范围不断扩大，2000年后扩大到除朝阳区东部以外的大部分主城区。相比较郊区而言，城区的热舒适度指数和变热幅度大，山前平原比山区热。且城区的冬季暖于郊区，寒冷和严寒日数也低于郊区，这种差距从80年代中后期逐渐明显，最大差距一年能达到10～20天；90年代后严寒区域范围逐渐缩小，平原地区的寒冷Et数较80年代平均减少10天。

Based on the meteorological data of 20 stations in Beijing form 1981 to 2010, the daily comfort indexes in 20 stations and the annual averages of warmest and coldest comfort indexes in urban and rural areas are calculated, as well as hot days, extreme hot days, cold days and severe cold days. The time and spatial variation characteristics of comfort indexes in urban and rural sites are analyzed, and the differences between urban and rural comfort indexes are compared. The results show that in the 1980s, there was no obvious difference between urban and rural sites in the warmest comfort index under the hot standard; however, since the 1990s, the summer comfort was warming obviously, and hot days and extreme hot days increased significantly, especially in the plain area. The spatial distribution of hot days and extreme hot days constantly extended, which extended to the most part of the urban area except for the eastern Chaoyang district after 2000. The warming magnitude was larger in urban areas than in rural areas, and it was warmer in plain areas than in mountain areas. The winters were warmer in Urban areas than in rural areas, and cold days and severe cold days were also less in the urban areas than in rural areas. The gap became obvious gradually from the mid and late 1980s, and the biggest gap can be up to 10 to 20 days in a year. The severe cold area reduced since the 1990s, and the cold days reduced 10 days compared with the 1980s.