DOI: 10.5194/hess-24-3381-2020
论文题名: Do stream water solute concentrations reflect when connectivity occurs in a small; pre-Alpine headwater catchment?
作者: Kiewiet L. ; Van Meerveld I. ; Stähli M. ; Seibert J.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2020
卷: 24, 期: 7 起始页码: 3381
结束页码: 3398
语种: 英语
Scopus关键词: Catchments
; Data streams
; Groundwater
; Hydrochemistry
; Mixing
; Rain
; Runoff
; Soil moisture
; Storms
; Stream flow
; Chemical compositions
; End-member mixing analysis
; Groundwater composition
; Hydrograph separation
; Hydrologic connectivity
; Hydrological connectivity
; Solute concentrations
; Streamwater chemistry
; Rivers
; baseflow
; chemical composition
; concentration (composition)
; connectivity
; groundwater resource
; headwater
; hillslope
; hydrography
; mixing
; rainfall-runoff modeling
; solute transport
; water chemistry
; Switzerland
英文摘要: Expansion of the hydrologically connected area during rainfall events causes previously disconnected areas to contribute to streamflow. If these newly contributing areas have a different hydrochemical composition compared to the previously connected contributing areas, this may cause a change in stream water chemistry that cannot be explained by simple mixing of rainfall and baseflow. Changes in stormflow composition are, therefore, sometimes used to identify when transiently connected areas (or water sources) contribute to stormflow.We identified the dominant sources of streamflow for a steep 20 ha pre-Alpine headwater catchment in Switzerland and investigated the temporal changes in connectivity for four rainfall events based on stream water concentrations and groundwater level data. First, we compared the isotopic and chemical composition of stormflow at the catchment outlet to the composition of rainfall, groundwater and soil water. Three-component end-member mixing analyses indicated that groundwater dominated stormflow during all events, and that soil water fractions were minimal for three of the four events. However, the large variability in soil and groundwater composition compared to the temporal changes in stormflow composition inhibited the determination of the contributions from the different groundwater sources. Second, we estimated the concentrations of different solutes in stormflow based on the mixing fractions derived from twocomponent hydrograph separation using a conservative tracer (-2H) and the measured concentrations of the solutes in baseflow and rainfall. The estimated concentrations differed from the measured stormflow concentrations for many solutes and samples. The deviations increased gradually with increasing streamflow for some solutes (e.g. iron and copper), suggesting increased contributions from riparian and hillslope groundwater with higher concentrations of these solutes and thus increased hydrological connectivity. The findings of this study show that solute concentrations partly reflect the gradual changes in hydrologic connectivity, and that it is important to quantify the variability in the composition of different source areas. © 2020 Copernicus GmbH. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/162651
Appears in Collections: 气候变化与战略
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作者单位: Kiewiet, L., Department of Geography, University of Zurich, Zurich, Switzerland; Van Meerveld, I., Department of Geography, University of Zurich, Zurich, Switzerland; Stähli, M., Swiss Federal Research Institute WSL, Birmensdorf, Switzerland; Seibert, J., Department of Geography, University of Zurich, Zurich, Switzerland, Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
Recommended Citation:
Kiewiet L.,Van Meerveld I.,Stähli M.,et al. Do stream water solute concentrations reflect when connectivity occurs in a small; pre-Alpine headwater catchment?[J]. Hydrology and Earth System Sciences,2020-01-01,24(7)