Help Needed with SWAT Check Warnings and RSWAT Calibration Results

[bharadwaj mandala]

Dear QSWAT Community,

I am currently working on developing and calibrating a SWAT model and would appreciate some guidance regarding issues I am encountering with both SWAT Check and RSWAT calibration.

I have attached four screenshots for reference. The first three screenshots are from SWAT Check, where I am seeing several warnings, including:

• Water yield may be excessive.
• Excessive surface runoff and low baseflow for some land-use types.
• High sediment yield for some crops/land uses and very low biomass for one land use.
• More than 95% of sediment is being deposited in-stream (approximately 98% channel deposition).

The hydrology summary shows relatively high surface runoff, and the in-stream sediment results particularly concern me because almost all of the upland sediment appears to be deposited within the channel system.

The fourth screenshot is from my RSWAT calibration. Although the simulated hydrograph follows some of the observed peaks, the model generally appears to overpredict streamflow, particularly during low- and moderate-flow periods. My current uncertainty statistics are:

p-factor calibration (validation): 0.64 (0.73)
r-factor calibration (validation): 6.47 (7.06)

The p-factor has improved during calibration, but the r-factor remains very high, and the best simulation still does not match the observed streamflow satisfactorily.

Could someone please help me understand where I may be going wrong in the model setup or calibration? In particular, I would appreciate suggestions on:

1. Which SWAT parameters or model inputs I should investigate to reduce the apparent streamflow overprediction and improve the water balance.
2. How I should address the excessive surface runoff/low baseflow warnings in SWAT Check.
3. What could cause approximately 98% in-stream sediment deposition, and which channel/sediment parameters or inputs should be checked.
4. Whether the SWAT Check warnings could be contributing to the poor RSWAT calibration results.
5. How I can improve the p-factor while substantially reducing the r-factor and obtain a more realistic calibration.
6. Whether I should correct the SWAT Check warnings before continuing calibration, or whether some of these warnings can reasonably remain depending on watershed characteristics.

I am relatively new to the SWAT calibration process, so any recommendations regarding parameters, parameter ranges, model setup, or a suggested troubleshooting sequence would be greatly appreciated.

I have attached the SWAT Check and RSWAT screenshots to provide more detail.

Thank you very much for your time and help.

Best regards,
Bharadwaj Mandala