HYPROP-FIT to Model Rock Water Retention Curves Estimated by Different Methods

The water retention curve, which relates the matric potential, y, to the water content, q, isessential to describe the flow processes in the unsaturated zone and provides useful information forenvironmental and engineering applications. There are few studies devoted to measuring the rockwater retention curves due to the rock's tightness, which makes it more technically difficult to usespecific methods. In this study, we tested four different methods to measure water retention curves oftwo lithotypes of carbonate porous rocks with the aim to find the most effective to be applied to rocksamples. Suction table, evaporation, Quasi-Steady Centrifuge, and WP4-T dewpoint potentiametermethods have been applied. The Quasi-Steady Centrifuge method proved to be the only one capableof determining water retention curves in the entire water content range and capturing the bimodalityof the tested media with respect to the other methods. The measured water retention data werefitted with HYPROP-FIT software that allows us to accurately describe the WRCs and obtain criticalparameters for the numerical simulation of flow and transport through the vadose zone, which playsa key role in various environmental issues.