State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2019 May 15;665:1003-1016. doi: 10.1016/j.scitotenv.2019.02.190. Epub 2019 Feb 13.
The optimized design of outdoor environment is of utmost importance due to its impact on human health, urban livability and energy consumption inside buildings. The outdoor thermal comfort and its spatiotemporal variations were assessed using Universal Thermal Climate Index (UTCI). Annual and seasonal UTCI were calculated using the daily dataset collected from 591 stations in China between 1966 and 2016. A REOF-cluster-EOF hybrid model was developed to optimize regionalization and assess regional-scale variations for UTCI. The results showed the following: (1) UTCI values decreased due to the increase of the latitude in China except for the Qinghai-Tibet Plateau. 69.5% of the total area of China experienced "no thermal stress" conditions in summer, whereas it was only 7.7% in winter. Additionally, the outdoor environment in summer had a wider "thermal comfort zone" than that in other seasons. (2) China was divided into a small number of regions with coherent UTCI changes using REOF analysis and K-means clustering algorithm. Eight homogeneous regions were obtained for annual UTCI. From spring to winter, the numbers of homogeneous regions were eight, nine, ten and seven, respectively. (3) Using EOF analysis, dominant patterns of UTCI in each region were extracted by the first two EOF modes, which accounted for >60% of the total variance. In the first mode, the significant upward trends of UTCI were detected in each region, suggesting the stronger outdoor heat stress. In the second mode, UTCI showed fluctuation between the cold and warm periods with different turning points between regions. Overall, the outdoor thermal comfort seemed to be improved more in high-latitude regions than that in low-latitude regions.
户外环境的优化设计至关重要，因为它会影响人类健康、城市宜居性和建筑物内部的能源消耗。采用通用热气候指数（UTCI）评估户外热舒适度及其时空变化。使用 1966 年至 2016 年期间在中国 591 个站点收集的日数据集计算了年和季节性 UTCI。开发了一种 REOF-聚类-EOF 混合模型，以优化区域化并评估 UTCI 的区域尺度变化。结果表明：（1）除青藏高原外，中国纬度增加导致 UTCI 值降低。69.5%的中国总面积在夏季处于“无热应激”状态，而冬季仅为 7.7%。此外，夏季户外环境的“热舒适区”比其他季节更宽。（2）采用 REOF 分析和 K-均值聚类算法，将中国划分为少数具有一致 UTCI 变化的区域。获得了 8 个用于年 UTCI 的均匀区域。从春季到冬季，均匀区域的数量分别为 8、9、10 和 7。（3）通过前两个 EOF 模式提取每个区域 UTCI 的主导模式，这两个模式占总方差的>60%。在第一模式中，每个区域的 UTCI 都检测到明显的上升趋势，表明户外热应激更强。在第二模式中，UTCI 在冷暖和暖期之间波动，不同区域之间存在不同的转折点。总体而言，高纬度地区的户外热舒适度似乎比低纬度地区有所改善。
