Sed Yield irregularity in the SWAT model

[Olaoluwa Anigboro-Napoleon]

Hello,

I implemented residue management function into the SWAT model by making some changes to the source code. I ran simulations with different scenarios of residue left on the field. The different scenarios are 0%, 25%, 40%, 55%, 75%, 90% and 99% of residue left on the field and in the results from output.std, surface runoff reduced as I increased the residue left on the field, which makes sense. However, for sediment yield, by the time I reached 75%, the results began to appear strange, and in some years, instead of sediment yield decreasing, it actually increased. For 99%, the sediment yield was greater than for some of the previous scenarios, which is not expected to be the case.

I think there might be an error in the equation I wrote in the code, or something else is wrong. Can anyone please guide me on what to do, or direct me to the codebase that handles the sediment yield calculation, so I can debug it? I would appreciate any information that can help me resolve this issue. Thank you!

Regards,

Ola.