College of Land Science and Technology, China Agricultural University, Beijing 100193, China; Key Laboratory of Land Quality, Ministry of Land and Resources, Beijing 100193, China.
College of Land Science and Technology, China Agricultural University, Beijing 100193, China; Key Laboratory of Land Quality, Ministry of Land and Resources, Beijing 100193, China.
Sci Total Environ. 2022 Nov 15;847:157662. doi: 10.1016/j.scitotenv.2022.157662. Epub 2022 Jul 27.
Excessive urban temperature exerts a substantially negative impact on urban sustainability. Three-dimensional (3D) landscapes have a great impact on urban thermal environments, while their heat conditions and driving factors still remain unclear. This study mapped urban 3D neighborhoods and their associated SUHI (surface urban heat island) intensities in summer daytime across 57 Chinese cities, and then explored their relationships, driving factors as well as implications. Nine categories of urban 3D neighborhoods existed in Chinese cities and the 3D neighborhood of High Density & Medium Rise (HDMR) contributed the largest share of urban areas. The distribution of 3D neighborhoods varied among cities due to their distinct natural and economic traits. The average SUHI intensity can amount to 4.27 °C across all Chinese 3D neighborhoods. High Density & Low Rise (HDLR) and HDMR presented higher SUHI intensities than other 3D neighborhoods in China. Urban green space (UGI) and building height (BH) had great influences on SUHI intensities. The relative contribution of UGI decreased with the increase of building density and building height, but BH presented the opposite trend. The interaction of urban 3D landscapes and function zones led to highly complicated urban thermal environments, with higher SUHI intensities in industrial zones. Besides, the SUHI intensities of 3D neighborhoods presented great diurnal and seasonal variations, with higher SUHI intensities in HDHR and HDMR at nighttime in winter and summer. What's more, urban residents may suffer unequal heat risk inside cities due to the deviations of SUHI intensities among different 3D neighborhoods. It could be a highly effective way to mitigate SUHI effects in cities by increasing urban greening and improving urban ventilation.
城市热岛效应对城市可持续发展造成了严重的负面影响。三维（3D）景观对城市热环境有很大的影响，但其热状况和驱动因素仍不清楚。本研究绘制了中国 57 个城市夏季白天的城市 3D 街区及其相关的表面城市热岛（SUHI）强度图，并探讨了它们之间的关系、驱动因素及其影响。中国城市存在九种 3D 街区类型，高密度中高层（HDMR）3D 街区占城市面积的比例最大。由于自然和经济特征的不同，城市之间的 3D 街区分布存在差异。所有中国 3D 街区的平均 SUHI 强度可达 4.27°C。高密度低层（HDLR）和 HDMR 的 SUHI 强度高于中国其他 3D 街区。城市绿地（UGI）和建筑高度（BH）对 SUHI 强度有很大影响。随着建筑密度和建筑高度的增加，UGI 的相对贡献减小，但 BH 则呈现相反的趋势。城市 3D 景观和功能区的相互作用导致了复杂的城市热环境，工业区的 SUHI 强度更高。此外，3D 街区的 SUHI 强度呈现出很大的昼夜和季节变化，冬季和夏季夜间 HDHR 和 HDMR 的 SUHI 强度更高。更重要的是，由于不同 3D 街区之间的 SUHI 强度存在偏差，城市居民可能会在城市内部遭受不平等的热风险。通过增加城市绿化和改善城市通风，可以有效地减轻城市热岛效应。
