Hi Peter!
I have a problem defining the van Genuchten function. I only have values for the saturated and the residual volumetric water contents, and of course the van Genuchten parameters A and n. FEFLOW ask me the saturated and residual saturations and the porosity. Knowing the porosity it is easy to calculate the saturation from the water content. But I don't know the porosity.
Studying relevant equation I tried to assume a random porosity greater than the saturated water content and smaller than 1. Then I calculated the congruent saturations with S=theta/n and entered the random porosity as the porosity.
Varying the porosity (and of course the congruent saturations) the results were always the same. My conclusion is that the program uses the saturations and the porosity to calculate the volumetric water contents.
Is that right?
