CSpace
Large spatiotemporal shifts of CO2 partial pressure and CO2 degassing in a monsoonal headwater stream
Luo, Jiachen1,2; Li, Siyue1; Ni, Maofei1,2; Zhang, Jing1,3
2019-12-01
摘要Carbon dioxide (CO2) emissions from rivers are a vital part of the global carbon budget. However, data from subtropical areas, especially in the headwater streams, are scare. Spatiotemporal dynamics and drives of partial pressure of CO2 (pCO(2)) and water-air CO2 fluxes (FCO2) in a monsoonal headwater stream Jinshui River of the Yangtze were unraveled. Our findings suggested that natural process (i.e., hydrology, CO2 outgassing and lithology) and human activities were recognized as significant players in regulating the variability of riverine pCO(2). The mean pCO(2) was significantly higher in the dry season (1562 +/- 975 mu atm) than the wet season (834 +/- 639 mu atm), seasonal trends of pCO(2) were controlled by in situ biogenic activities and rainfall events. The slight fluctuations of pCO(2) from upstream to downstream along main stem implied the mixed influences of distinct water environments and anthropogenic disturbance. Correlation analysis showed that environmental factors, i.e., temperature, pH, TN and DOC were relevant to pronounced spatial and seasonal variability of pCO(2). We highlighted that high water-air CO2 flux was estimated at 343 +/- 413 mmol/m(2/)d (dry: 542 +/- 477 mmol/m(2/)d vs wet: 192 +/- 278 mmol/m (2/)d) in the monsoonal headwater stream, and the watershed-scale carbon budget demonstrated carbon loss via atmospheric exchange was 1.2 times the riverine dissolved carbon export. Our results would fill a large gap in the headwater stream of the Yangtze, and help to accurately estimate the regional to global CO2 outgassing from rivers to the atmosphere.
关键词Carbon degassing The Yangtze River Partial pressure of CO2 Spatial-temporal variation Water-air gas exchange
DOI10.1016/j.jhydrol.2019.124135
发表期刊JOURNAL OF HYDROLOGY
ISSN0022-1694
卷号579页码:10
通讯作者Li, Siyue(syli2006@163.com)
收录类别SCI
WOS记录号WOS:000500371200006
语种英语