Controlling mizuRoute Output Related to Water Balance Print, and Possibility of Keeping Them in Output Files

[ShervanGharari]

Hi @nmizukami,

It appears we're encountering an issue where the processor hangs after a successful mizuRoute simulation. From what I can tell, this is likely caused by excessive output being written to the log file (inside Python) — particularly due to a large number of warning messages printed at each time step for segments and lakes exceeding the water balance tolerance.

I also came across the checkMassBalance flag in the control file. However, it’s unclear whether this flag is intended to control verbosity, or if it only activates the mass balance check logic internally without affecting print behavior (for example, this line can still print even if verbose is false).

Do we currently have such an output feature in mizuRoute? I couldn’t find anything related in the control file, but I apologize if I’ve overlooked something. It would be very useful to have the water balance, per seg and time, and also per segment for the entire simulation time, in the output file.

Thank you in advance!

[nmizukami]

Hi Shervan, checkMassBalance is indeed new, but this is to check domain wide water balance (integral of storage change over domain = integral of input over the domain - integral of outflow from the most downstream reaches over the domain), not per reach/lake. per-reach water balance is printed out in log whenever it exceeds the tolerance. is it way off (so something missing) or how much is the balance error roughly?

lake water balance tolerance is lakeWBtol=1.e-3_dp [mm] now (in public_var.f90). if you make this huge (this is not solution though, just test), the model properly finish?

[ShervanGharari]

Hi @nmizukami,

The lake water balance currently triggers warnings because runoff is no longer being added to lakes, even though it’s still included in the water balance calculations. As a result, every lake generates a warning message, leading to a very large number of print statements during the simulation. While the simulation does complete successfully (which is good), the volume of these messages becomes problematic — they're captured in the log files or returned by Python’s multiprocessing interface, and I suspect this might be causing the workflow to hang.

In my next pull request, I plan to explore a more robust fix for managing lake water balance under different input conditions for lakes and reservoirs. In the meantime, I have a simpler question: Is there a way to suppress all print statements in mizuRoute using a control file flag, rather than modifying the executable or adding a flag when simulating mizuRoute?

For now, I’ve temporarily commented out the specific water balance print statements to test whether that resolves the issue.

Any thoughts or suggestions would be greatly appreciated, and thank you again!

[nmizukami]

Hi Shervan, right now, we don't have any in control file. It may be reasonable to add water balance tolerance in control file. it is now hard-coded in pulic_var.f90 and can be exposed in a control file (so should be one line addition). Now, this is only for lake, but maybe river reach could use the same tolerance (may need testing)