Help with SWAT+ Calibration: Simulated Flow Much Higher Than Observed

[bharadwaj mandala]

Hello All,

I am doing calibration step in SWAT+ (RSWAT) using the weather data; however, the simulated streamflow is significantly higher than the observed flow. I have been trying to identify the cause of this discrepancy but have not been able to determine the issue.

Could you please provide your guidance on the possible reasons for this overestimation of flow? I would greatly appreciate any suggestions regarding model setup, calibration parameters, watershed delineation, or input datasets that may be contributing to the problem.

I am also sharing the watershed elevation data for your review in case it helps identify any issues related to delineation or slope representation.

also shared QGIS project file.

Thank you for your time and assistance. I look forward to your suggestions.

Best regards,

Bharadwaj Mandala

PhD Student

Department of Civil and Environmental Engineering

Rowan University

214-(516)-9958

linkedin.com/in/bharadwajmandala

[Natalja C.]

Hello,

Here are a few things:

1. Is it SWAT+ or SWAT? You state that the model is in swat+, but the calibration parameters are for swat2012, so which is it?

2. Your precip is 1.2k mm, btu your ET is like in the arctic. No wonder you have such  a big runoff. I think there is an issue with your solar radiation or/and temperature data or/and weather generator, or/and all of the climate data.

Evaluate your model from a process standpoint, and not from purely runoff. Get your ET within reasonable range for your area, and you should see the water balance adjusting to correct values.

HTH,

Natalja