Inverting surface GPR data to estimate wetting and drainage water retention curves in laboratory

In this study we present a laboratory experiment where we monitor volumetric water content in a 80-cm sand column using a Ground Penetrating Radar (GPR). Antennae were placed at the top of the sand column. The water table was set at different levels during drainage and wetting processes in order to exhibit hysteresis on the sand water retention function. We used the Mualem-van Genuchten model to fit retention curve data and model the hysteresis using different α parameters for drying and wetting processes.