TY - JOUR

T1 - Using time-lapse gravity for groundwater model calibration: An application to alluvial aquifer storage

A1 - Christiansen,Lars

A1 - Binning,Philip John

A1 - Rosbjerg,Dan

A1 - Bauer-Gottwein,Peter

A1 - Andersen,Ole Baltazar

AU - Christiansen,Lars

AU - Binning,Philip John

AU - Rosbjerg,Dan

AU - Bauer-Gottwein,Peter

AU - Andersen,Ole Baltazar

PB - American Geophysical Union

PY - 2011

Y1 - 2011

N2 - The estimation of hydrological model parameters by calibration to field data is a critical step in the modeling process. However, calibration often fails because of parameter correlation. Here it is shown that time-lapse gravity data can be combined with hydraulic head data in a coupled hydrogeophysical inversion to decrease parameter correlation in groundwater models. This is demonstrated for a model of riverbank infiltration where combined inversion successfully constrains hydraulic conductivity and specific yield in both an analytical and a numerical groundwater model. A sensitivity study shows that time-lapse gravity data are especially useful to constrain specific yield. Furthermore, we demonstrate that evapotranspiration, and riverbed conductance are better constrained by coupled inversion to gravity and head data than to head data alone. When estimating the four parameters simultaneously, the six correlation coefficients were reduced from unity when only head data were employed to significantly lower values when gravity and head data were combined. Our analysis reveals that the estimated parameter values are not very sensitive to the choice of weighting between head and gravity data over a large interval of relative weights. Copyright 2011 by the American Geophysical Union.

AB - The estimation of hydrological model parameters by calibration to field data is a critical step in the modeling process. However, calibration often fails because of parameter correlation. Here it is shown that time-lapse gravity data can be combined with hydraulic head data in a coupled hydrogeophysical inversion to decrease parameter correlation in groundwater models. This is demonstrated for a model of riverbank infiltration where combined inversion successfully constrains hydraulic conductivity and specific yield in both an analytical and a numerical groundwater model. A sensitivity study shows that time-lapse gravity data are especially useful to constrain specific yield. Furthermore, we demonstrate that evapotranspiration, and riverbed conductance are better constrained by coupled inversion to gravity and head data than to head data alone. When estimating the four parameters simultaneously, the six correlation coefficients were reduced from unity when only head data were employed to significantly lower values when gravity and head data were combined. Our analysis reveals that the estimated parameter values are not very sensitive to the choice of weighting between head and gravity data over a large interval of relative weights. Copyright 2011 by the American Geophysical Union.

U2 - 10.1029/2010WR009859

DO - 10.1029/2010WR009859

JO - Water Resources Research

JF - Water Resources Research

SN - 0043-1397

IS - 6

VL - 47

SP - W06503

ER -