Quantifying shallow subsurface water and heat dynamics using coupled hydrological-thermal-geophysical inversion

Journal Article · Wed Aug 31 04:00:00 UTC 2016 · Hydrology and Earth System Sciences (Online)

DOI: https://doi.org/10.5194/hess-20-3477-2016 · OSTI ID:1313253

Tran, Anh Phuong; Dafflon, Baptiste; Hubbard, Susan S.; Kowalsky, Michael B.; Long, Philip; Tokunaga, Tetsu K.; Williams, Kenneth H.

Improving our ability to estimate the parameters that control water and heat fluxes in the shallow subsurface is particularly important due to their strong control on recharge, evaporation and biogeochemical processes. The objectives of this study are to develop and test a new inversion scheme to simultaneously estimate subsurface hydrological, thermal and petrophysical parameters using hydrological, thermal and electrical resistivity tomography (ERT) data. The inversion scheme – which is based on a nonisothermal, multiphase hydrological model – provides the desired subsurface property estimates in high spatiotemporal resolution. A particularly novel aspect of the inversion scheme is the explicit incorporation of the dependence of the subsurface electrical resistivity on both moisture and temperature. The scheme was applied to synthetic case studies, as well as to real datasets that were autonomously collected at a biogeochemical field study site in Rifle, Colorado. At the Rifle site, the coupled hydrological-thermal-geophysical inversion approach well predicted the matric potential, temperature and apparent resistivity with the Nash–Sutcliffe efficiency criterion greater than 0.92. Synthetic studies found that neglecting the subsurface temperature variability, and its effect on the electrical resistivity in the hydrogeophysical inversion, may lead to an incorrect estimation of the hydrological parameters. The approach is expected to be especially useful for the increasing number of studies that are taking advantage of autonomously collected ERT and soil measurements to explore complex terrestrial system dynamics.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1313253
• Journal Information: Hydrology and Earth System Sciences (Online), Journal Name: Hydrology and Earth System Sciences (Online) Journal Issue: 9 Vol. 20; ISSN 1607-7938
• Publisher: European Geosciences Union (EGU)Copyright Statement
• Country of Publication: Germany
• Language: English