FePEST and Porosity

Hello,

I am attempting to setup a transient FePEST calibration of a 3D, 4 Layer model, under phreatic unconfined aquifer conditions. I am (reasonably) confident in my hydraulic conditions, however my understanding is that porosity will hae a greater effect then the compressibility under unconfied conditions. I am trying to run a simple calibration which only allows porosity to be varied. However I get an error in FePEST that states that a parameter needs to be log transformed (why?). Does anyone know how I can setup this simulation with porosity which does not really behave like hydraulic conductivity and is not log distributed?

Thanks
Jeff

From my little experience with PEST, the transform shouldn't matter much for a parameter. The only effect would be PEST's sensitivity to that parameter (I presume) and as long as your bounds are (0,1], PEST will just be super sensitive to porosity. Still not sure why it wants porosity to be log transformed though.. you should be able to set it to "none"?!

Hi Jeff,
It should be possible to set the transformation to "none" instead of "log". When is the error message prompted exactly (e.g., after changing the setting, pressing OK in the dialog) and what is the exact text of the error message? Have any of the involved parameters been tied to other parameters?

IM DOING THE SAME AS HE SAID. BUT IT IS TAKING SO MUCH TIME TO RUN THE MODEL FOR THE FIRST TIME. I WAITED SO LONG, THEN CANCELED. IS THAT DUE TO ANY MISTAKE I HAV DONE?

It's difficult to give recommendations without knowing the details of the model. I suggest to contact the FEFLOW Support: https://www.mikepoweredbydhi.com/support