Open AccessCalibrating Vadose Zone Models with Time‐Lapse Gravity Data
Author(s) -
Christiansen Lars,
Haarder Eline B.,
Hansen Allan B.,
Looms Majken C.,
Binning Philip J.,
Rosbjerg Dan,
Andersen Ole B.,
Bauer-Gottwein Peter
Publication year - 2011
Publication title -
vadose zone journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.036
H-Index - 81
ISSN - 1539-1663
DOI - 10.2136/vzj2010.0127
Subject(s) - vadose zone , infiltration (hvac) , water content , soil science , hydraulic conductivity , geology , soil water , ground penetrating radar , hydrology (agriculture) , borehole , groundwater , environmental science , geotechnical engineering , radar , meteorology , physics , computer science , telecommunications
The vadose zone plays an important role in the hydrologic cycle. Various geophysical methods can determine soil water content variations in time and space in volumes ranging from a few cubic centimeters to several cubic meters. In contrast to the established methods, time‐lapse gravity measurements of changes in soil water content do not rely on a petrophysical relationship between the measured quantity and the water content but give a direct measure of the mass change in the soil. Only recently has the vadose zone been systematically incorporated when ground‐based gravity data are used to infer hydrologic information. In this study, changes in the soil water content gave rise to a measurable signal in a forced infiltration experiment on a 107‐m 2 grassland area. Time‐lapse gravity data were able to constrain the van Genuchten soil hydraulic parameters in both a synthetic example and a field experiment with forced infiltration. The most significant reduction in parameter uncertainty was achieved for the saturated water content, while gravity data had some ability to constrain the saturated hydraulic conductivity and the van Genuchten n Cross‐borehole ground penetrating radar data were used to support the interpretation and control of the gravity data.