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Continuous measurement and modeling of CO 2 losses from a peatland stream during stormflow events
Author(s) -
Dinsmore K. J.,
Billett M. F.
Publication year - 2008
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2008wr007284
Subject(s) - peat , environmental science , hydrology (agriculture) , streams , baseflow , drainage basin , groundwater , storm , wetland , soil water , atmosphere (unit) , streamflow , soil science , geology , ecology , meteorology , computer network , oceanography , physics , geotechnical engineering , cartography , computer science , geography , biology
While streams draining peatland and wetland systems are known to be supersaturated in CO 2 with respect to the atmosphere, relatively little is known about short‐term temporal variability in response to extreme hydrological events. Here, we use submerged, nondispersive infrared (NDIR) sensors to make continuous measurements of CO 2 concentrations during 18 storm events in a Scottish peatland stream. Individual storms exhibited 3 distinct types of hysteresis loop. We suggest that differences in loop form may be due to differences in the relative contributions of soil water or differences in the contributing catchment source area. We found a negative concentration‐discharge relationship over the full study period, suggesting that CO 2 ‐rich deep peat/groundwater was the major source of aquatic CO 2 under low flow conditions. By removing the effect of dilution and estimating additions and losses of CO 2 , we also show the importance of both surface peat CO 2 inputs into the stream and evasion loss during stormflow. The best model of temporal variability in CO 2 was achieved by separating the data set into “stormflow” and “dry periods.” Downstream CO 2 export during the study period was dominated by stormflow events (71%), highlighting the importance of accurately accounting for high‐flow CO 2 sources.