𝔖 Bobbio Scriptorium
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Lateral moisture flow beneath a sandy hillslope without an apparent impeding layer

✍ Scribed by James T. McCord; Daniel B. Stephens


Book ID
102860840
Publisher
John Wiley and Sons
Year
1987
Tongue
English
Weight
843 KB
Volume
1
Category
Article
ISSN
0885-6087

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✦ Synopsis


Part of a small drainage basin on the Sevilleta National Wildlife Refuge (about 25 km north of Socorro, NM) was intensively instrumented with soil monitoring equipment to estimate natural ground-water recharge. Soil-moisture data were analysed with special attention to characterizing the influence of topography on the direction of vadose water flow paths in fine to medium aeolian sand. Moisture content data were obtained by the neutron scattering technique, and hydraulic head data were obtained using tensiometers. In addition, tracer experiments were conducted on a sandy hillslope to delineate the flow paths of vadose water. The results indicate that there is a strong lateral component to unsaturated flow on a hillslope, even in the absence of apparent sublayers of much lower permeability. Darcian calculations estimate the long-term, steady, deep flux beneath a concave location to be about 4 per cent of an assumed mean annual precipitation of 20cm. The deep soil water flux downward varied by several orders of magnitude during the 17 month period of record.