TY - JOUR
T1 - Considerations for measuring pressure head and water content in inclined boreholes
AU - Hinnell, A. C.
AU - Ferré, T. P.A.
PY - 2008/12
Y1 - 2008/12
N2 - Angled boreholes have been proposed to improve water content and pressure head monitoring in deep vadose zones by reducing the impact of the borehole on measurements by placing sensors below undisturbed soil. However, the borehole casing distorts the flow field, which may impact measurements made with sensors placed on or in the boreholes. We examined a wide range of soil types, background fluxes, and casing radii and angles of inclination to predict the error in water content and pressure head measurements that arise due to this flow disruption under unit gradient flow. We found that placing pressure head and water content sensors 110° and 120° from the top of the borehole, respectively, minimizes the effects of flow perturbation. Under some conditions, it may be possible to use the perturbation of the flow field caused by the casing to estimate hydraulic parameter values.
AB - Angled boreholes have been proposed to improve water content and pressure head monitoring in deep vadose zones by reducing the impact of the borehole on measurements by placing sensors below undisturbed soil. However, the borehole casing distorts the flow field, which may impact measurements made with sensors placed on or in the boreholes. We examined a wide range of soil types, background fluxes, and casing radii and angles of inclination to predict the error in water content and pressure head measurements that arise due to this flow disruption under unit gradient flow. We found that placing pressure head and water content sensors 110° and 120° from the top of the borehole, respectively, minimizes the effects of flow perturbation. Under some conditions, it may be possible to use the perturbation of the flow field caused by the casing to estimate hydraulic parameter values.
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U2 - 10.1029/2008WR007122
DO - 10.1029/2008WR007122
M3 - Article
AN - SCOPUS:59649093850
SN - 0043-1397
VL - 44
JO - Water Resources Research
JF - Water Resources Research
IS - 12
M1 - W12444
ER -