TY - JOUR
T1 - Impacts of future urban expansion on summer climate and heat-related human health in eastern China
AU - Cao, Qian
AU - Yu, Deyong
AU - Georgescu, Matei
AU - Wu, Jianguo
AU - Wang, Wei
N1 - Funding Information:
This study was supported by the Chinese Ministry of Science and Technology through the National Basic Research Program of China ( 2014CB954301 and 2014CB954303 ) and the National Natural Science Foundation of China through the Science Fund for Creative Research Groups ( 41621061 ). MG was supported by the National Science Foundation Sustainability Research Network (SRN) Cooperative Agreement 1444758, the Urban Water Innovation Network (UWIN). We are grateful to the National Supercomputer Center in Tianjin for allocating supercomputer resources.
Publisher Copyright:
© 2017
PY - 2018/3
Y1 - 2018/3
N2 - China is the largest and most rapidly urbanizing nation in the world, and is projected to add an additional 200 million city dwellers by the end of 2030. While this rapid urbanization will lead to vast expansion of built-up areas, the possible climate effect and associated human health impact remain poorly understood. Using a coupled urban-atmospheric model, we first examine potential effects of three urban expansion scenarios to 2030 on summer climate in eastern China. Our simulations indicate extensive warming up to 5 °C, 3 °C, and 2 °C in regard to low- (> 0%), high- (> 75%), and 100% probability urban growth scenarios, respectively. The partitioning of available energy largely explains the changes in 2-m air temperatures, and increased sensible heat flux with higher roughness length of the underlying urban surface is responsible for the increase of nighttime planetary boundary layer height. In the extreme case (the low-probability expansion pathway), the agglomeration of impervious surfaces substantially reduces low-level atmospheric moisture, consequently resulting in large-scale precipitation reduction. However, the effect of near-surface warming far exceeds that of moisture reduction and imposes non-negligible thermal loads on urban residents. Our study, using a scenario-based approach that accounts for the full range of urban growth uncertainty by 2030, helps better evaluate possible regional climate effects and associated human health outcomes in the most rapidly urbanizing areas of China, and has practical implications for the development of sustainable urban regions that are resilient to changes in both mean and extreme conditions.
AB - China is the largest and most rapidly urbanizing nation in the world, and is projected to add an additional 200 million city dwellers by the end of 2030. While this rapid urbanization will lead to vast expansion of built-up areas, the possible climate effect and associated human health impact remain poorly understood. Using a coupled urban-atmospheric model, we first examine potential effects of three urban expansion scenarios to 2030 on summer climate in eastern China. Our simulations indicate extensive warming up to 5 °C, 3 °C, and 2 °C in regard to low- (> 0%), high- (> 75%), and 100% probability urban growth scenarios, respectively. The partitioning of available energy largely explains the changes in 2-m air temperatures, and increased sensible heat flux with higher roughness length of the underlying urban surface is responsible for the increase of nighttime planetary boundary layer height. In the extreme case (the low-probability expansion pathway), the agglomeration of impervious surfaces substantially reduces low-level atmospheric moisture, consequently resulting in large-scale precipitation reduction. However, the effect of near-surface warming far exceeds that of moisture reduction and imposes non-negligible thermal loads on urban residents. Our study, using a scenario-based approach that accounts for the full range of urban growth uncertainty by 2030, helps better evaluate possible regional climate effects and associated human health outcomes in the most rapidly urbanizing areas of China, and has practical implications for the development of sustainable urban regions that are resilient to changes in both mean and extreme conditions.
KW - China
KW - Climate change
KW - Health impact
KW - Urbanization
KW - WRF
UR - http://www.scopus.com/inward/record.url?scp=85038371162&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85038371162&partnerID=8YFLogxK
U2 - 10.1016/j.envint.2017.12.027
DO - 10.1016/j.envint.2017.12.027
M3 - Article
C2 - 29272777
AN - SCOPUS:85038371162
SN - 0160-4120
VL - 112
SP - 134
EP - 146
JO - Environment international
JF - Environment international
ER -