TY - JOUR
T1 - Are water bodies effective for urban heat mitigation? Evidence from field studies of urban lakes in two humid subtropical cities
AU - Yao, Lingye
AU - Sailor, David J.
AU - Yang, Xiaoshan
AU - Xu, Genyu
AU - Zhao, Lihua
N1 - Funding Information:
This research is supported by the National Key Research and Development Project of China (No. 2019YFE0124500 ), the National Natural Science Foundation of China (No. 51878288 ), the Project of State Key Laboratory of Subtropical Building and Urban Science, South China University of Technology (No. 2021ZB01 ), and the China Scholarship Council Program (No. 202006150097 ). Instrument supply from Dr. Guang Chen at Guangdong University of Technology and volunteer work in the field measurement from Xiang Zhang, Guanghong Bi, and Jiayi Liu are greatly appreciated. Authors sincerely acknowledge the anonymous Reviewers for their helpful and constructive comments.
Funding Information:
This research is supported by the National Key Research and Development Project of China (No. 2019YFE0124500), the National Natural Science Foundation of China (No. 51878288), the Project of State Key Laboratory of Subtropical Building and Urban Science, South China University of Technology (No. 2021ZB01), and the China Scholarship Council Program (No. 202006150097). Instrument supply from Dr. Guang Chen at Guangdong University of Technology and volunteer work in the field measurement from Xiang Zhang, Guanghong Bi, and Jiayi Liu are greatly appreciated. Authors sincerely acknowledge the anonymous Reviewers for their helpful and constructive comments.
Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/11/1
Y1 - 2023/11/1
N2 - Blue infrastructure is considered a nature-based solution to address urban heat problems. However, the potential nocturnal urban heat island (UHI) effect of water bodies has not been investigated and elaborated thoroughly. Besides, existing studies have primarily focused on surface temperature and are limited to individual cities during summer daytime. In this study, screen-height air temperature/humidity measurements at lake, residential, and rural sites in two humid subtropical cities of China (Nanjing, Guangzhou) were conducted continuously for one year. The UHI intensity (UHII), urban moisture island intensity (UMII, evaluated by humidity ratio difference), and heat index (HI) were analyzed across different weather conditions and time scales. Results demonstrated that (1) compared to residential sites, urban lakes can help mitigate urban heat excess, while this capability at night is not as significant as during daytime; compared to rural sites, urban lakes exhibit diurnal thermal behavior of daytime cooling and nighttime warming, with a weak urban cool island intensity (UCII) of 0.1–0.6 °C during the day but a significant UHII of 1.2–1.3 °C at night during warm months (May–September), which is comparable to residential sites with UHII of 1.1–1.3 °C; (2) urban moisture excess tends to occur during nighttime and cold seasons; (3) compared to rural sites, lakes contribute to a good relief on heat stress during daytime, but a significant negative effect at night due to the intensified warming and humidifying. Findings of this study can provide empirical evidence to help better understand the effectiveness of water bodies for urban heat mitigation.
AB - Blue infrastructure is considered a nature-based solution to address urban heat problems. However, the potential nocturnal urban heat island (UHI) effect of water bodies has not been investigated and elaborated thoroughly. Besides, existing studies have primarily focused on surface temperature and are limited to individual cities during summer daytime. In this study, screen-height air temperature/humidity measurements at lake, residential, and rural sites in two humid subtropical cities of China (Nanjing, Guangzhou) were conducted continuously for one year. The UHI intensity (UHII), urban moisture island intensity (UMII, evaluated by humidity ratio difference), and heat index (HI) were analyzed across different weather conditions and time scales. Results demonstrated that (1) compared to residential sites, urban lakes can help mitigate urban heat excess, while this capability at night is not as significant as during daytime; compared to rural sites, urban lakes exhibit diurnal thermal behavior of daytime cooling and nighttime warming, with a weak urban cool island intensity (UCII) of 0.1–0.6 °C during the day but a significant UHII of 1.2–1.3 °C at night during warm months (May–September), which is comparable to residential sites with UHII of 1.1–1.3 °C; (2) urban moisture excess tends to occur during nighttime and cold seasons; (3) compared to rural sites, lakes contribute to a good relief on heat stress during daytime, but a significant negative effect at night due to the intensified warming and humidifying. Findings of this study can provide empirical evidence to help better understand the effectiveness of water bodies for urban heat mitigation.
KW - Field measurement
KW - Heat stress
KW - Nature-based solution
KW - Urban heat island
KW - Urban moisture island
KW - Water body
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U2 - 10.1016/j.buildenv.2023.110860
DO - 10.1016/j.buildenv.2023.110860
M3 - Article
AN - SCOPUS:85172226081
SN - 0360-1323
VL - 245
JO - Building and Environment
JF - Building and Environment
M1 - 110860
ER -