Hello,
I am trying to simulate the rotational plan of irrigation canals. This means that i have a main channel which has inline structures and from this main channel, numerous distributries are offtaking. I have inserted lateral weirs (gated structures) for the offtaking channels. You may call them head regulators.
Now, i am maintaining FULL SUPPLY LEVEL at the inline structures so that off taking canals can be fed. In case an offtaking canal is not properly feeded (LOWERING OF WATER HEAD), i need to control the gates of that particular disty.
For this i have used UNSTEADY RULES. Now the problem i am currently facing is that I am telling the model that when the discharge at a lateral weir “X” is 6 cusecs, then adjust the gates of lateral weir “Y” to ensure 10 cusecs and in case “X” is not getting its desired flows, close the gates of “Y”.
So for off taking canal Y, the code will be something:
*BS = Lateral Weir Gate Flow for Channel X (defining the variable)
If BS >=6 cusecs then
Ensure design flows for Y
Else close the gates of Y
End if
The problem is in the first line (the one with *). I was expecting that it will pick up the discharge value at the weir X for the current time step but it is picking a very weird value which is actually not the discharge passing through it. (checked in the log file)
My computational timestep is one minute, so as per my understanding, it should pick up discharges at every timestep which are actually passing through weir X. However, it should be noticed that weir X has the condition DESIRED FLOWS = 6 cusecs. This means that model is adjusting its gates conutinously to ensure 6 cusecs.
Any idea where i am not getting it? Help or guidance will be very much appreciated. Thank you.
Regards
Nayyar ASIF