How are eff_frac and sumq_frac interpreted and applied in SWAT+ irrigation?

[Anita Nurhami]

Hi! I'm trying to better understand how eff_frac and sumq_frac interact in the irrigation module.

1. Does eff_frac refer to the fraction of irrigation water that infiltrates (i.e., effective for crops), or the fraction that is lost?
2. Is sumq_frac applied to the total irrigation amount, or only to the ineffective part (i.e., 1 - eff_frac)?
3. Do eff_frac and sumq_frac need to sum to 1, or are they independent?

Example:
If I apply 100 mm irrigation with eff_frac = 0.2 and sumq_frac = 0.8, what exactly happens to the 100 mm?

Thanks in advance!