DOI: 10.1007/s10533-014-0010-2
Scopus记录号: 2-s2.0-84918796099
论文题名: Long-term nitrate removal in a stream riparian zone
作者: Hill A.R. ; Devito K.J. ; Vidon P.G.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 121, 期: 2 起始页码: 425
结束页码: 439
语种: 英语
英文关键词: Denitrification
; Groundwater
; Long-term research
; Nitrate removal
; Nitrogen saturation
; Riparian zone
英文摘要: The long-term capacity of riparian zones in regulating groundwater nitrate fluxes is not well understood. This study analyses patterns of nitrate removal for the period 1994–2012 at two sites in a river floodplain that have received high groundwater nitrate loading from a large upland aquifer for over 32 years. During the study, mean NO3 −–N concentrations entering the riparian zone varied between 20–30 and 30–42 mg/L at the upstream and downstream sites respectively, but did not show any clear inter-annual trend. A permeable sand layer in the riparian zone is underlain by a regional aquitard at a depth of 5–6 m and 4 m at the upstream site and downstream site respectively. Denitrification resulted in a decline in nitrate concentrations as lateral groundwater flow in the sand layer interacted with buried peat and channel bar deposits that range up to 3 m in depth at both riparian sites. This interaction was greater at the downstream site where the organic deposits extend down to <1 m from the aquitard in some locations. At the upstream site nitrate removal efficiency in the sand layer, at depths of 3–4 m ~20 m from the river bank, declined from 68 % in 1996–1998 to 42 % in 2009–2012. A smaller decline from 92 to 82 % occurred in the sand layer 10 m from the river bank during the study. In contrast, no clear pattern of change was evident at the downstream site where a nitrate removal efficiency of 98–100 % occurred at the river bank in most years between 1994 and 2012. These data suggest that the long-term nitrate removal performance of some riparian zones may decline if carbon availability for denitrification becomes limited as a result of variations in the quantity, quality and location of subsurface organic deposits that interact with deeper groundwater flowpaths. © 2014, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83708
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Department of Geography, York University, Toronto, ON, Canada; Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada; Department of Forest and Natural Resources Management, State University of New York, Syracuse, NY, United States
Recommended Citation:
Hill A.R.,Devito K.J.,Vidon P.G.. Long-term nitrate removal in a stream riparian zone[J]. Biogeochemistry,2014-01-01,121(2)