Rights statement: An edited version of this paper was published by AGU. Copyright 2016 American Geophysical Union
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Rights statement: Copyright 2016 American Geophysical Union
Final published version, 6.38 MB, PDF document
Available under license: CC BY: Creative Commons Attribution 4.0 International License
Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Integrated time-lapse geoelectrical imaging of wetland hydrological processes
AU - Uhlemann, S. S.
AU - Sorensen, J. P. R.
AU - House, A. R.
AU - Wilkinson, P. B.
AU - Roberts, C.
AU - Gooddy, D. C.
AU - Binley, A. M.
AU - Chambers, J. E.
PY - 2016/3
Y1 - 2016/3
N2 - Wetlands provide crucial habitats, are critical in the global carbon cycle, and act as key biogeochemical and hydrological buffers. The effectiveness of these services is mainly controlled by hydrological processes, which can be highly variable both spatially and temporally due to structural complexity and seasonality. Spatial analysis of 2D geoelectrical monitoring data integrated into the interpretation of conventional hydrological data has been implemented to provide a detailed understanding of hydrological processes in a riparian wetland. This study shows that a combination of processes can define the resistivity signature of the shallow subsurface, highlighting the seasonality of these processes and its corresponding effect on biogeochemical processesthe wetland hydrology. Groundwater exchange between peat and the underlying river terrace deposits, spatially and temporally defined by geoelectrical imaging and verified by point sensor data, highlighted the groundwater dependent nature of the wetland. A 30 % increase in peat resistivity was shown to be caused by a nearly entire exchange of the saturating groundwater. For the first time, we showed that automated interpretation of geoelectrical data can be used to quantify shrink-swell of expandable soils, affecting hydrological parameters, such as, porosity, water storage capacity, and permeability. This study shows that an integrated interpretation of hydrological and geophysical data can significantly improve the understanding of wetland hydrological processes. Potentially, this approach can provide the basis for the evaluation of ecosystem services and may aid in the optimization of wetland management strategies.
AB - Wetlands provide crucial habitats, are critical in the global carbon cycle, and act as key biogeochemical and hydrological buffers. The effectiveness of these services is mainly controlled by hydrological processes, which can be highly variable both spatially and temporally due to structural complexity and seasonality. Spatial analysis of 2D geoelectrical monitoring data integrated into the interpretation of conventional hydrological data has been implemented to provide a detailed understanding of hydrological processes in a riparian wetland. This study shows that a combination of processes can define the resistivity signature of the shallow subsurface, highlighting the seasonality of these processes and its corresponding effect on biogeochemical processesthe wetland hydrology. Groundwater exchange between peat and the underlying river terrace deposits, spatially and temporally defined by geoelectrical imaging and verified by point sensor data, highlighted the groundwater dependent nature of the wetland. A 30 % increase in peat resistivity was shown to be caused by a nearly entire exchange of the saturating groundwater. For the first time, we showed that automated interpretation of geoelectrical data can be used to quantify shrink-swell of expandable soils, affecting hydrological parameters, such as, porosity, water storage capacity, and permeability. This study shows that an integrated interpretation of hydrological and geophysical data can significantly improve the understanding of wetland hydrological processes. Potentially, this approach can provide the basis for the evaluation of ecosystem services and may aid in the optimization of wetland management strategies.
KW - wetland
KW - resistivity monitoring
KW - shrink-swell
KW - layered groundwater system
KW - ELECTRICAL-RESISTIVITY TOMOGRAPHY
KW - NORTHERN PEATLAND
KW - GEOPHYSICAL EVIDENCE
KW - INTERFACE DETECTION
KW - RIPARIAN WETLANDS
KW - DC RESISTIVITY
KW - DATA INVERSION
KW - SOIL-MOISTURE
KW - WATER-TABLE
KW - PLANT-ROOTS
U2 - 10.1002/2015WR017932
DO - 10.1002/2015WR017932
M3 - Journal article
VL - 52
SP - 1607
EP - 1625
JO - Water Resources Research
JF - Water Resources Research
SN - 0043-1397
IS - 3
ER -