TY - JOUR
T1 - Diurnal pattern and driving mechanisms of the thermal effects of an urban pond
AU - Yao, Lingye
AU - Sailor, David J.
AU - Zhang, Xiang
AU - Wang, Junsong
AU - Zhao, Lihua
AU - Yang, Xiaoshan
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 Science, South China University of Technology (No. 2021ZB01 ), and the China Scholarship Council Program (No. 202006150097 ). The authors sincerely acknowledge the Editor and four anonymous Reviewers for their helpful and constructive comments. Helpful advice from Sandeep Sabu, Dr. Yuanhui Zhu, and Dr. Dylan S. Connor of ASU are appreciated.
Publisher Copyright:
© 2023
PY - 2023/4
Y1 - 2023/4
N2 - Water bodies are often considered an effective solution to cool their surroundings in hot summers. However, their potential adverse nocturnal warming effect has not yet been investigated thoroughly or considered in current urban planning strategies. This study evaluates the diurnal thermal effects of an urban pond in Nanjing, China, and explores the underlying mechanisms through energy-balance analysis using the Bowen ratio method. In-situ air temperature/humidity, water temperature profile, and upward and downward short- and long-wave radiation on hot summer days were measured. Results demonstrate that compared with a reference soil-site, the pond exerted a moderate daytime cooling effect (0.6 °C) but a pronounced nocturnal warming effect (1.8 °C). During the day, the energy input Rnet (net radiation flux) comprised 77% QS (heat storage) and 23% QE (latent heat flux), while QH (sensible heat flux) was negligible. At night, a negative QS acted as a heat source from the pond, which was released through QH (5%), QE (51%), and Rnet (44%). Results of this study improve our understanding of the thermal effects of urban water bodies, and can be used to inform urban planners and landscape designers regarding implementation of water bodies in the urban context for creating sustainable cool cities and communities.
AB - Water bodies are often considered an effective solution to cool their surroundings in hot summers. However, their potential adverse nocturnal warming effect has not yet been investigated thoroughly or considered in current urban planning strategies. This study evaluates the diurnal thermal effects of an urban pond in Nanjing, China, and explores the underlying mechanisms through energy-balance analysis using the Bowen ratio method. In-situ air temperature/humidity, water temperature profile, and upward and downward short- and long-wave radiation on hot summer days were measured. Results demonstrate that compared with a reference soil-site, the pond exerted a moderate daytime cooling effect (0.6 °C) but a pronounced nocturnal warming effect (1.8 °C). During the day, the energy input Rnet (net radiation flux) comprised 77% QS (heat storage) and 23% QE (latent heat flux), while QH (sensible heat flux) was negligible. At night, a negative QS acted as a heat source from the pond, which was released through QH (5%), QE (51%), and Rnet (44%). Results of this study improve our understanding of the thermal effects of urban water bodies, and can be used to inform urban planners and landscape designers regarding implementation of water bodies in the urban context for creating sustainable cool cities and communities.
KW - Energy balance
KW - Field measurement
KW - Nighttime warming effect
KW - Urban microclimate
KW - Urban water bodies
UR - http://www.scopus.com/inward/record.url?scp=85149783041&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85149783041&partnerID=8YFLogxK
U2 - 10.1016/j.scs.2023.104407
DO - 10.1016/j.scs.2023.104407
M3 - Article
AN - SCOPUS:85149783041
SN - 2210-6707
VL - 91
JO - Sustainable Cities and Society
JF - Sustainable Cities and Society
M1 - 104407
ER -