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Tracer and hydrometric study of preferential flow in large undisturbed soil cores from the Georgia Piedmont, USA

Hydrological Processes

By:
, ,
DOI: 10.1002/(SICI)1099-1085(19990215)13:2<139::AID-HYP703>3.0.CO;2-E

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Abstract

We studied the temporal patterns of tracer throughput in the outflow of large (30 cm diameter by 38 cm long) undisturbed cores from the Panola Mountain Research Watershed, Georgia. Tracer breakthrough was affected by soil structure and rainfall intensity. Two rainfall intensities (20 and 40 mm hr-1) for separate Cl- and Br- amended solutions were applied to two cores (one extracted from a hillslope soil and one extracted from a residual clay soil on the ridge). For both low and high rainfall intensity experiments, preferential flow occurred in the clay core, but not in the hillslope core. The preferential flow is attributed to well-developed interpedal macrochannels that are commonly found in structured clay soils, characteristic of the ridge site. However, each rainfall intensity exceeded the matrix infiltration capacity at the top of the hillslope core, but did not exceed the matrix infiltration capacity at the middle and bottom of the hillslope core and at all levels in the clay core. Localized zones of saturation created when rainfall intensity exceeds the matrix infiltration capacity may cause water and tracer to overflow from the matrix into macrochannels, where preferential flow occurs to depth in otherwise unsaturated soil. Copyright © 1999 John Wiley & Sons, Ltd.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Tracer and hydrometric study of preferential flow in large undisturbed soil cores from the Georgia Piedmont, USA
Series title:
Hydrological Processes
DOI:
10.1002/(SICI)1099-1085(19990215)13:2<139::AID-HYP703>3.0.CO;2-E
Volume
13
Issue:
2
Year Published:
1999
Language:
English
Publisher:
John Wiley & Sons, Ltd.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Hydrological Processes
First page:
139
Last page:
155
Number of Pages:
17