We also discuss the effects of the grain size on the dynamic capillary pressure and the fitting of the equilibrium suction head.
MGAM Fitting Parameters for Dynamic Capillary Pressure. Hsu and Hilpert  pointed out that the parameters [??] and [beta] in the MGAM are related to the dynamic effect on the capillary pressure, and their values might not be the same for different initial water contents, porosities, and grain sizes.
Hilpert, "Water infiltration into prewetted porous media: dynamic capillary pressure and Green-Ampt modeling," Advances in Water Resources, vol.
Hilpert, "Dynamic capillary pressure during water infiltration: experiments and Green-Ampt modeling," Water Resources Research, vol.