Storativity and pseudo-unsaturated modelling

Does using a free&moveable surface or a phreatic surface change the storage properties (Storativity/specific yield) of my model as cells change from saturated to unsaturated? Which material properties are varied in response to degrees of saturation for these two methods, do they both simply scale volume and conductivity directly by the saturation? What equations are used to calculate these relationships if not?

Thanks
Martin

Dear Martin,
I'd like to ask you to have a look at the User Manual, page 38: http://www.feflow.info/uploads/media/feflow_user_manual_01.pdf. There you can find a basic description of the different methods.