• How to deal with the evaporation?

    Dear all,
        I am trying to set up a 3-D model for a transient flow. But I have trouble with dealing with the evaporation. Because the evaporation varies with the groundwater table.How I import the evaporation in the "Flow Materials"?
       Someone had told me the interface manager IFM can help solve this problem. Can anyone tell me how to use the IFM programming?
       Thanks a lot for your help !