Point Sources Not Affecting Channel Flow in Mid-Watershed Setup

[Luqman Hakim]

I am modeling a mid-watershed reach using QSWAT+ and SWAT+ Editor. My study area has:

• 2 upstream inflows (as point sources)
• 1 outlet for calibration
• Water abstractions for irrigation and municipal supply (as negative point sources)

I have added the inflows as point sources with daily data (time period matches simulation period). SWAT+ Check confirms that point sources are present in the model. However, when I run the simulation:

1. Simulated flow at outlet does not reflect the additional point source inputs
2. Calibration results: NSE = -0.21 (very poor), simulated flow is much lower than observed
3. Key finding: When I compare the SQLite database outputs:
   • Model WITH point sources: flo_out values at outlet channel
   • Model WITHOUT point sources: flo_out values at outlet channel
   • Result: Both show identical values!

This confirms that point sources are not being routed to the channel system.

What should I do then? Please, anyone give me an advice.