This pane is on the MODFLOW Features tab of the Object Properties dialog box.
EVAPORATION_IRRIGATION_FRACTION (FEI) is the fraction of a cropped area that is irrigated but is not covered by a crop. It should be less than or equal to 1 - FTR (That is FEI + FTR <= 1), but this is not required. It can be viewed as the area in which irrigated water is exposed to the sun and evaporates (for example on top of bare soil space between row crops).
If FEI + FTR > 1, then the final consumptive use can be larger than the input specified due to evaporation. It can viewed as the water that evaporates before it reaches the crop or evaporates while sitting atop of the leaves.
Including the keyword EVAPORATION_IRRIGATION_FRACTION_SUM_ONE_CORRECTION forces FMP to correct FEI + FTR > 1 by setting FEI = 1 - FTR (Not Recommended)
