SWAT-MODFLOW with smaller MODFLOW domain & QSWATMOD problem

[iste G]

Hi everyone,

 

I've meet some problems while setting my model and using the QSWATMOD2.

 

1.     MODFLOW domain is smaller than the SWAT catchment

My study area requires a detailed groundwater MODFLOW model only for a critical sub-region. This means my MODFLOW grid is inside the overall SWAT catchment area.

What will happen? Will the model produce an incorrect water balance because the regions outside the MODFLOW domain are not properly receiving or exchanging groundwater data calculated by SWAT?

If some data error will happen?Are there any solutions without expanding the MODFLOW domain or reducing the SWAT area?

 

QSWATMOD2 problem

 

When I select 'No', the simulation fails. When I select 'Yes', the simulation runs successfully. Why does this situation happen?

 

Any advice would be  helpful. I can provide more details if needed.

 

Thanks in advance!

Best regards,

James

[Seonggyu Park]

Hi James,

There will be no groundwater–surface water interaction in areas where they do not overlap. However, in SWAT areas that do not have a MODFLOW grid, the groundwater module in SWAT will still be simulated.
Regarding the activation option, does the model crash without running any simulation? If you would like to run only the SWAT simulation for now, please use the SWAT binary file while I check the code on my end.

Best,
Seonggyu

[iste G]

Hi Seonggyu,

There will be no groundwater–surface water interaction in areas where they do not overlap. However, in SWAT areas that do not have a MODFLOW grid, the groundwater module in SWAT will still be simulated.

Thank you for your reply. Does this mean I don’t need to worry about issues arising from the MODFLOW grid not covering the entire SWAT simulation area, since the SWAT groundwater module will still be active in uncovered area?

Regarding the activation option, does the model crash without running any simulation? If you would like to run only the SWAT simulation for now, please use the SWAT binary file while I check the code on my end.

When I selected "Run SWAT only", the model would start and run, but it would shut down after only a few seconds. The output files (output.std/output.hru/output.rch)are generated, but they contain no data.

Best regards,

James

env...@gmail.com 在 2025年12月17日 星期三上午11:55:55 [UTC+8] 的信中寫道：