Rational Method - how is initial tc calculated?

[katiedoyle]

I'm running a Rational Method model. I go into the Run Simulation dialog and click on 'Compute. . .' to compute I using the IDF curves. There is already a Time of Concentration in the Specified tc box. Where does this come from? When I go back to the Run Simulation dialog and click on 'Compute. . . ' to Compute Tc using Basin Data, none of the default methods and variables give me the time of concentration that was shown in the Specified Tc box. I do not have a Time Computation Coverage set up.

[Chris Smemoe]

Hi Katie,

I don't know where the Tc number came from when you first went to the IDF dialog. WMS should be getting this number from the Tc value displayed in the Rational Method analysis dialog. If you compute this value from the basin data or from a Tc coverage, this computed value should show up in the IDF dialog. Hope this helps,

Chris