Inquiry regarding recharge results and associated modeling considerations

[Sophia Wang (SophiaMnn)]

Dear developers and friends,  

I hope this message finds you well. I would like to seek your insights regarding the SWAT-MODFLOW simulation. Thank you in advance for your timely responses despite your busy schedules.

Question 1:
Is the "recharge in" value in the MODFLOW output file derived from the percolation process simulated in SWAT? If so, why does this value remain constant across all stress periods? Upon examining the "swatmf_out_MF_recharge_monthly" file, I observed that the recharge amounts vary across different grid cells in this file. Therefore, I would like to confirm whether the IN&OUT data from the MODFLOW output file can be used as the final recharge results.

Question 2:
I would also like to ask about the MODFLOW modeling process for the entire watershed. It appears that the thickness of the aquifer and the initial groundwater levels significantly influence the simulation results. If we simplify the aquifer structure in the upstream areas of the watershed by unifying the bottom elevation of these areas with that of the downstream regions and then assign different parameter values based on sub-regions, would this approach be feasible?

Thank you once again for your valuable input.

Best regards,  
Jiamei Wang (Sophia)

[Seonggyu Park]

Hi Jiamei,

Q1: Yes, the "recharge in" value in the MODFLOW output is derived from the percolation simulated in SWAT. You can consider the MODFLOW output as the final recharge results.
Q2: Yes, your approach sounds reasonable. However, you should evaluate your model results, including the water balance, to ensure they are realistic.

Best,
Seonggyu