Vertical Hydrologic Exchange Flows Control Methane Emissions from Riverbed Sediments

Chen, Kewei5; Chen, Xingyuan1; Stegen, James C.1; Villa, Jorge A.2; Bohrer, Gil3; Song, Xuehang1; Chang, Kuang-Yu4; Kaufman, Matthew1; Liang, Xiuyu5; Guo, Zhiling5; Roden, Eric E.6; Zheng, Chunmiao5

2023-02-01

10.1021/acs.est.2c07676

ENVIRONMENTAL SCIENCE & TECHNOLOGY   Impact Factor & Quartile

0013-936X

1520-5851

CH4 emissions from inland waters are highly uncertain in the current global CH4 budget, especially for streams, rivers, and other lotic systems. Previous studies have attributed the strong spatiotemporal heterogeneity of riverine CH4 to environmental factors such as sediment type, water level, temperature, or particulate organic carbon abundance through correlation analysis. However, a mechanistic understanding of the basis for such heterogeneity is lacking. Here, we combine sediment CH4 data from the Hanford reach of the Columbia River with a biogeochemical-transport model to show that vertical hydrologic exchange flows (VHEFs), driven by the difference between river stage and groundwater level, determine CH4 flux at the sediment-water interface. CH4 fluxes show a nonlinear relationship with the magnitude of VHEFs, where high VHEFs introduce O2 into riverbed sediments, which inhibit CH4 production and induce CH4 oxidation, and low VHEFs cause transient reduction in CH4 flux (relative to production) due to reduced advective CH4 transport. In addition, VHEFs lead to the hysteresis of temperature rise and CH4 emissions because high river discharge caused by snowmelt in spring leads to strong downwelling flow that offsets increasing CH4 production with temperature rise. Our findings reveal how the interplay between in-stream hydrologic flux besides fluvial-wetland connectivity and microbial metabolic pathways that compete with methanogenic pathways can produce complex patterns in CH4 production and emission in riverbed alluvial sediments.

riverine CH4 emission sediment biogeochemical cycling vertical hydrologic exchange flows microbial-explicit model temperature hysteresis

SCI

English

NI Journal Papers

First ; Corresponding

National Key R&D program of China[2021YFC3200502] ; National Natural Science Foundation of China["42141003","41931292"] ; U.S. Department of Energy, Office of Biological and Environmental Research, Environmental System Science (ESS) program["DE-SC0016217","DE-SC0020309","DE-AC05-76RL01830"]

Engineering ; Environmental Sciences & Ecology

Engineering, Environmental ; Environmental Sciences

WOS:000936767800001

AMER CHEMICAL SOC

ENVIRONMENT/ECOLOGY

Web of Science

1.Pacific Northwest Natl Lab, Richland, WA 99354 USA
2.Univ Louisiana Lafayette, Sch Geosci, Lafayette, LA 70506 USA
3.Ohio State Univ, Dept Civil Environm & Geodet Engn, Columbus, OH 43210 USA
4.Lawrence Berkeley Natl Lab, Climate & Ecosyst Sci Div, Berkeley, CA 94720 USA
5.Southern Univ Sci & Technol, Sch Environm Sci & Engn, Shenzhen 518055, Peoples R China
6.Univ Wisconsin, Dept Geosci, Madison, WI 53706 USA

Chen, Kewei,Chen, Xingyuan,Stegen, James C.,et al. Vertical Hydrologic Exchange Flows Control Methane Emissions from Riverbed Sediments[J]. ENVIRONMENTAL SCIENCE & TECHNOLOGY,2023.

Chen, Kewei.,Chen, Xingyuan.,Stegen, James C..,Villa, Jorge A..,Bohrer, Gil.,...&Zheng, Chunmiao.(2023).Vertical Hydrologic Exchange Flows Control Methane Emissions from Riverbed Sediments.ENVIRONMENTAL SCIENCE & TECHNOLOGY.

Chen, Kewei,et al."Vertical Hydrologic Exchange Flows Control Methane Emissions from Riverbed Sediments".ENVIRONMENTAL SCIENCE & TECHNOLOGY (2023).