TY - JOUR
T1 - Coastal reservoirs as a source of nitrous oxide
T2 - Spatio-temporal patterns and assessment strategy
AU - Yang, Ping
AU - Lu, Miaohui
AU - Tang, Kam W.
AU - Yang, Hong
AU - Lai, Derrick Y.F.
AU - Tong, Chuan
AU - Chun, Kwok Pan
AU - Zhang, Linhai
AU - Tang, Chen
N1 - Funding Information:
This research was supported by the National Science Foundation of China (No. 41801070 , 41671088 ), the Natural Science Foundation of Fujian Province (No. 2020J01136 ), the Research Grants Council, University Grants Committee of the Hong Kong Special Administrative Region, China ( CUHK458913 ), and the CUHK Direct Grant ( SS15481 ), Open Research Fund Program of Jiangsu Key Laboratory of Atmospheric Environment Monitoring & Pollution Control ( KHK1806 ), A projected funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and the Minjiang Scholar Programme . We would like to thank Yifei Zhang, Guanghui Zhao and Ling Li of the School of Geographical Sciences, Fujian Normal University, for their field assistance.
Funding Information:
This research was supported by the National Science Foundation of China (No. 41801070, 41671088), the Natural Science Foundation of Fujian Province (No. 2020J01136), the Research Grants Council, University Grants Committee of the Hong Kong Special Administrative Region, China (CUHK458913), and the CUHK Direct Grant (SS15481), Open Research Fund Program of Jiangsu Key Laboratory of Atmospheric Environment Monitoring & Pollution Control (KHK1806), A projected funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and the Minjiang Scholar Programme. We would like to thank Yifei Zhang, Guanghui Zhao and Ling Li of the School of Geographical Sciences, Fujian Normal University, for their field assistance.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/10/10
Y1 - 2021/10/10
N2 - Coastal reservoirs are widely regarded as a viable solution to the water scarcity problem faced by coastal cities with growing populations. As a result of the accumulation of anthropogenic wastes and the alteration of hydroecological processes, these reservoirs may also become the emission hotspots of nitrous oxide (N2O). Hitherto, accurate global assessment of N2O emission suffers from the scarcity and low spatio-temporal resolution of field data, especially from small coastal reservoirs with high spatial heterogeneity and multiple water sources. In this study, we measured the surface water N2O concentrations and emissions at a high spatial resolution across three seasons in a subtropical coastal reservoir in southeastern China, which was hydrochemically highly heterogeneous because of the combined influence of river runoff, aquacultural discharge, industrial discharge and municipal sewage. Both N2O concentration and emission exhibited strong spatio-temporal variations, which were correlated with nitrogen loading from the river and wastewater discharge. The mean N2O concentration and emission were found to be significantly higher in the summer than in spring and autumn. The results of redundancy analysis showed that NH4+-N explained the greatest variance in N2O emission, which implied that nitrification was the main microbial pathway for N2O production in spite of the potentially increasing importance of denitrification of NO3−-N in the summer. The mean N2O emission across the whole reservoir was 107 μg m−2 h−1, which was more than an order of magnitude higher than that from global lakes and reservoirs. Based on our results of Monte Carlo simulations, a minimum of 15 sampling points per km2 would be needed to produce representative and reliable N2O estimates in such a spatially heterogeneous aquatic system. Overall, coastal reservoirs could play an increasingly important role in future climate change via their N2O emission to the atmosphere as water demand and anthropogenic pressure continue to rise.
AB - Coastal reservoirs are widely regarded as a viable solution to the water scarcity problem faced by coastal cities with growing populations. As a result of the accumulation of anthropogenic wastes and the alteration of hydroecological processes, these reservoirs may also become the emission hotspots of nitrous oxide (N2O). Hitherto, accurate global assessment of N2O emission suffers from the scarcity and low spatio-temporal resolution of field data, especially from small coastal reservoirs with high spatial heterogeneity and multiple water sources. In this study, we measured the surface water N2O concentrations and emissions at a high spatial resolution across three seasons in a subtropical coastal reservoir in southeastern China, which was hydrochemically highly heterogeneous because of the combined influence of river runoff, aquacultural discharge, industrial discharge and municipal sewage. Both N2O concentration and emission exhibited strong spatio-temporal variations, which were correlated with nitrogen loading from the river and wastewater discharge. The mean N2O concentration and emission were found to be significantly higher in the summer than in spring and autumn. The results of redundancy analysis showed that NH4+-N explained the greatest variance in N2O emission, which implied that nitrification was the main microbial pathway for N2O production in spite of the potentially increasing importance of denitrification of NO3−-N in the summer. The mean N2O emission across the whole reservoir was 107 μg m−2 h−1, which was more than an order of magnitude higher than that from global lakes and reservoirs. Based on our results of Monte Carlo simulations, a minimum of 15 sampling points per km2 would be needed to produce representative and reliable N2O estimates in such a spatially heterogeneous aquatic system. Overall, coastal reservoirs could play an increasingly important role in future climate change via their N2O emission to the atmosphere as water demand and anthropogenic pressure continue to rise.
KW - Coastal reservoir
KW - Greenhouse gases
KW - Nitrous oxide
KW - Spatial heterogeneity
KW - Wastewater discharge
KW - Water management
UR - http://www.scopus.com/inward/record.url?scp=85111028976&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.147878
DO - 10.1016/j.scitotenv.2021.147878
M3 - Journal article
C2 - 34090167
AN - SCOPUS:85111028976
SN - 0048-9697
VL - 790
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 147878
ER -
