Mitigation of urban heat island in China (2000–2020) through vegetation-induced cooling

• Published in: Sustainable cities and society Vol. 112; p. 105599
• Main Authors: Wu, Bowei, Zhang, Yuanyuan, Wang, Yuan, He, Yanmin, Wang, Jiawei, Wu, Yifan, Lin, Xiaobiao, Wu, Shidai
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2024
• Subjects: City afforestation; Surface temperature variations; Urban and non-urban areas; Urban heat island effect; Vegetation cooling benefits; Vegetation cooling benefits; Urban and non-urban areas; Urban heat island effect; Surface temperature variations; City afforestation
• ISSN: 2210-6707; 2210-6715
• DOI: 10.1016/j.scs.2024.105599

•Vegetation changes modulate temperature dynamics across 304 Chinese cities.•Vegetation impacts on urban-rural temperature gradients, 2000–2020, assessed.•96 % of urban areas cool as vegetation increases, effect fades toward rural zones.•Urban afforestation rose by 4.35 %, cooling 67 % of cities by 0.58 °C from 2000 to 2020.•Vegetation alters urban cooling and rural warming, reducing UHI by 0.56 ± 0.35 °C. City afforestation serves as a robust strategy for thermal mitigation. Employing multisource satellite data, we explored the impact of vegetation cover on temperature dynamics across urban and rural sectors in Chinese cities. Our analysis reveals that a 1 % increase in vegetation coverage corresponds to a reduction in surface temperature by 0.099 °C to 0.102 °C in urban environments. However, the cooling effect diminishes from urban to rural areas, where increased vegetation occasionally results in warming. Further, the temperature reduction tends to stabilize at higher vegetation levels, as demonstrated in grid-based evaluations. Significantly, variations in urban population density substantially modulate these cooling effects. Over the period 2000–2020, afforestation increased vegetation coverage by 4.35 % in urban areas, which led to cooling in 67.43 % of the analyzed cities, with an average surface temperature decline of 0.58 °C. Additionally, our findings document a notable attenuation of the urban heat island (UHI) effect over time, with an average decrease of 0.56 ± 0.35 °C. This reduction primarily results from the thermoregulatory effects of changes in vegetation coverage, which cool urban areas and may warm rural ones. Our study underscores the critical role of afforestation in urban climate management and its efficacy in attenuating urban heat waves and UHI effects.