TY - JOUR
T1 - Occurrence of subsurface lateral flow in the Shale Hills Catchment indicated by a soil water mass balance method
AU - Guo, L.
AU - Fan, B.
AU - Zhang, J.
AU - Lin, H.
N1 - Funding Information:
This research was supported in part by the U.S. National Science Foundation Hydrologic Sciences Program (Grant EAR-1416881, PI: H. Lin) and the National Science Foundation grants EAR-0725019 (C. Duffy) EAR-1239285 (S. Brantley) and EAR-1331726 (S. Brantley) for the SSHCZO. It was carried out in Penn State's Stone Valley Forest, which is supported and managed by the Penn State's Forestland Management Office in the College of Agricultural Sciences. We thank two anonymous reviewers, the Associate Editor, the Deputy Editor (Rob Bryant) and the Editor in Chief (Margaret Oliver) for their valuable comments and suggestions, which have helped improve the quality of this paper.
Publisher Copyright:
© 2018 British Society of Soil Science
PY - 2018/9
Y1 - 2018/9
N2 - Subsurface lateral flow (SLF) contributes substantially to hillslope runoff. However, because of the lack of appropriate methods, field investigation of SLF at the hillslope and catchment scales has been limited. Recently, high-frequency soil moisture monitoring has been tested to characterize SLF. This study presented a simple approach to determine SLF based on soil water mass balance and compared this method with an established approach that used the depth-specific soil moisture response time to precipitation to identify preferential flow. The new method defined the occurrence of SLF when the increase in soil water storage was greater than the accumulated quantity of effective precipitation during a rain event. We applied this method to a 10-minute resolution soil moisture dataset collected over 3 years from nine soil profiles along a concave hillslope. We found that (i) SLF frequency derived by the proposed method matched well with preferential flow frequency obtained by the established method (r > 0.9), (ii) precipitation and initial soil wetness together controlled the generation of SLF, precipitation intensity determined whether or not the hillslope produced SLF and the quantity of precipitation governed the spatial extent of SLF, and (iii) topographic and small-scale soil features led to spatially different frequencies of SLF during small storms. Identifying SLF from a soil moisture time series over an entire rain event complements the established method based on soil moisture dynamics at the beginning of an event. Applying both methods creates the potential to measure SLF frequency and vertical preferential flow frequency, respectively. Soil moisture sensor networks have improved the large-scale investigation of such preferential flows. Highlights: How can the occurrence of subsurface lateral flow (SLF) be detected by soil moisture time series? A simple approach is proposed to detect SLF in a forested hillslope using soil water mass balance. Three-year SLF frequency obtained by the new method agreed with that from an established method. Rain, topography and soil attributes control the generation and spatial distribution of SLF.
AB - Subsurface lateral flow (SLF) contributes substantially to hillslope runoff. However, because of the lack of appropriate methods, field investigation of SLF at the hillslope and catchment scales has been limited. Recently, high-frequency soil moisture monitoring has been tested to characterize SLF. This study presented a simple approach to determine SLF based on soil water mass balance and compared this method with an established approach that used the depth-specific soil moisture response time to precipitation to identify preferential flow. The new method defined the occurrence of SLF when the increase in soil water storage was greater than the accumulated quantity of effective precipitation during a rain event. We applied this method to a 10-minute resolution soil moisture dataset collected over 3 years from nine soil profiles along a concave hillslope. We found that (i) SLF frequency derived by the proposed method matched well with preferential flow frequency obtained by the established method (r > 0.9), (ii) precipitation and initial soil wetness together controlled the generation of SLF, precipitation intensity determined whether or not the hillslope produced SLF and the quantity of precipitation governed the spatial extent of SLF, and (iii) topographic and small-scale soil features led to spatially different frequencies of SLF during small storms. Identifying SLF from a soil moisture time series over an entire rain event complements the established method based on soil moisture dynamics at the beginning of an event. Applying both methods creates the potential to measure SLF frequency and vertical preferential flow frequency, respectively. Soil moisture sensor networks have improved the large-scale investigation of such preferential flows. Highlights: How can the occurrence of subsurface lateral flow (SLF) be detected by soil moisture time series? A simple approach is proposed to detect SLF in a forested hillslope using soil water mass balance. Three-year SLF frequency obtained by the new method agreed with that from an established method. Rain, topography and soil attributes control the generation and spatial distribution of SLF.
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U2 - 10.1111/ejss.12701
DO - 10.1111/ejss.12701
M3 - Article
AN - SCOPUS:85051077317
SN - 1351-0754
VL - 69
SP - 771
EP - 786
JO - European Journal of Soil Science
JF - European Journal of Soil Science
IS - 5
ER -