Estimation of Spatial Distribution of Water Content by Using Hydraulic Tomography and Gravity Measurements

Abstract:

Saturated water content (θ_s) is not only an important parameter for unsaturated groundwater flow modeling, but also a key parameter for multiphase flow transport in porous media. θ_s is typically obtained through filed sampling and laboratory experiment. However, obtaining the detailed spatial distribution of θ_s through a large amount of field point samples for a field area is an arduous task. To efficiently derive the distribution of θ_s for a field area, this study proposed a method that integrates hydraulic head and gravity measurements by using hydraulic tomography (HT) method. A synthetic case is used to demonstrate the capability of the developed method. Our preliminary results show that gravity measurements are helpful to constrain the estimated distribution of θ_s. By comparing the results estimated by the proposed method with that of original HT, the uncertainty of the distribution of θ_s estimated by the proposed method is improved. Our studies show that the proposed method is practicable and could be useful to reduce the uncertainty of field-scale characterization.