DOI: 10.1002/2015GL064200
论文题名: A physical explanation for the development of redox microzones in hyporheic flow
作者: Briggs M.A. ; Day-Lewis F.D. ; Zarnetske J.P. ; Harvey J.W.
刊名: Geophysical Research Letters
ISSN: 0094-9290
EISSN: 1944-9021
出版年: 2015
卷: 42, 期: 11 起始页码: 4402
结束页码: 4410
语种: 英语
英文关键词: biogeochemical
; denitrification
; hyporheic
; mass transfer
; microsite
; microzone
Scopus关键词: Denitrification
; Mass transfer
; Oxic sediments
; Anaerobic respiration
; Biogeochemical
; Hydrologic conditions
; Hyporheic
; Microsite
; microzone
; Pore-network modeling
; Saturated sediments
; Stream flow
英文摘要: Recent observations reveal a paradox of anaerobic respiration occurring in seemingly oxic-saturated sediments. Here we demonstrate a residence time-based explanation for this paradox. Specifically, we show how microzones favorable to anaerobic respiration processes (e.g., denitrification, metal reduction, and methanogenesis) can develop in the embedded less mobile porosity of bulk-oxic hyporheic zones. Anoxic microzones develop when transport time from the streambed to the pore center exceeds a characteristic uptake time of oxygen. A two-dimensional pore-network model was used to quantify how anoxic microzones develop across a range of hyporheic flow and oxygen uptake conditions. Two types of microzones develop: flow invariant and flow dependent. The former is stable across variable hydrologic conditions, whereas the formation and extent of the latter are sensitive to flow rate and orientation. Therefore, pore-scale residence time heterogeneity, which can now be evaluated in situ, offers a simple explanation for anaerobic signals occurring in oxic pore waters. ©2015. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84934344077&doi=10.1002%2f2015GL064200&partnerID=40&md5=3ddb7bd4cdadac775b1318f7b9eaf695
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8906
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Office of Groundwater, Branch of Geophysics, U.S. Geological Survey, Storrs, CT, United States
Recommended Citation:
Briggs M.A.,Day-Lewis F.D.,Zarnetske J.P.,et al. A physical explanation for the development of redox microzones in hyporheic flow[J]. Geophysical Research Letters,2015-01-01,42(11).