Time span settings for multiple 25yr storm durations???

[jpetermann1900]

I am running multiple duration storms to determine the critical 25 yr event for pre/post analysis. I can set the time span in "calc settings" and run the model for each storm and all is well, but after I run through all storm events (1hr, 2hr, 4hr, 8hr, 24hr...setting applicable time spans for each independently), the printed the report for all selected storm scenarios reflects only the last time span value entered (24hrs). Obviously, this is now incorrect for all other durations (from 1-8hrs).

How do I "lock" in a specific time span value each storm scenario and be sure it "remembers" this value for each separate storm event? (i.e., set time span = 8hrs for the FDOT 25yr, 8hr event...and then set time span = 4 hrs for the FDOT 25yr, 4 hr event, etc.) As of now, I have execute/print each event separately...which eliminates use of the multiple event print option.

I hope this makes sense. Thanks in advance for any suggestions on how to remedy this issue.

 

[Twinkie]

I thought time span governed the entire file, and all hydrographs within. I don't think you can set individual time spans for different storm events within the same file??

So if I put in a time span of 0.01 - 96 hours, that is going to be the time span for all storm events within the file.

If I wanted to run your scenario, I would create individual files for each scenario you want to run.

 

[psmart]

HydroCAD uses the same calculation time span for all events. When using different storm durations, you should set the time span for the longest duration.

Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[jpetermann1900]

Thanks for the recent posts. However, it just seems like there should be a way to identify a specific time span for each event within one HydroCad file; otherwise, what good is the batch print function for reports all or specifically selected storms? As it stands now, I have to set the time span and then print a storm...then, re-set the span and print again. I understand the logic you mentioned for setting the span to the greatest event duration (to encompass all)...but doing so makes the hydrographs look odd (i.e., a 24hr time span for the 25yr/1hr event shows peak flows to the far left of graph and then 23 +/- hours remaining of flat line zero). Why would there be an option to print ALL storms as a batch plot (which makes perfect sense to save time), if the time span function automatically defaults to the latest value overall, thus screwing up all but one event within the model? There HAS to be a way to set the span value for each independently within a file, or simply turn it off and allow the rainfall event parameters to govern. This program seems sophisticated, so I'd expect there to be an easy fix for batching reports. If not, then this software is sorely flawed from a convenience perspective.

Thanks again, Twinkie and psmart for the replies.

 

[psmart]

The event definitions contain only the parameters on the "Rainfall" tab. Data on the other tabs, such as the time span, are not part of the event definitions. Trust me, I know - I wrote the software.

Although it might seem like a good idea to include the time span in the event definitions, this would raise other issues, such as the inability to change the time span for multiple events with a single setting. Using different time spans (and time steps) could also make the event comparison invalid. It's better to use common calculation settings for all events - even if the shorter events "look odd".

Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[beej67]

Just be glad you're not using XP-SWMM and have to port all the points of your hydrograph out to a text file, trim it by hand, and import to Excel to make a graph that's legible.

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