Monte Carlo simulation summary results

[JM]

Hi

I am running a Monte Carlo simulation and in the output text file under ‘Summary of Runs for Critical Duration Analysis’ I am only getting results for AEP events 2 to 50.
Is there a way to get the summary to show results for 1 in 100 events as well?
I am using RORB V6.32 and ARR2016.

Thanks

[Matt Scorah]

Hi,

In order to generate results for a given AEP of interest you require runs that have been generated using rainfalls either side of that AEP – therefore, to estimate 1 in 100 floods you need rainfalls rarer than 1 in 100. For this reason RORB will not report Monte Carlo results for the first and last AEPs specified in your IFD input.

When downloading IFDs from the BoM website design rainfalls are split into three different tables – Very Frequent, IFD (up to an AEP of 1 in 100) and Rare (AEP of 1 in 100 to 1 in 2000). You will need to download both the IFD and Rare tables and combine them (either in the RORB interface or Excel) and rerun the model to get results for an AEP of 1 in 100.

I hope this helps!

[JM]

Thank-you for the quick reply.

[_nikkatorres]

Hi, I’m running Monte Carlo for extreme events and sometimes there are unreliable values. What does “ie bound by interval contributions to AEP > 20% total” mean?

ex: I ran 200yr, 500yr, 1000yr, 2000yr, 5000yr, 10 000yr, and 20 000yr. Only 2000yr was reliable

Peak flows for selected AEPs (* indicates value unreliable, ie bounded by interval contributions to AEP > 20% total)

No. AEP(1inY) Peak 01
1 500 475.43*
2 1000 484.84*
3 2000 551.69
4 5000 701.04*
5 10000 841.63*

Any general advice as to how I can always ensure that my values are reliable?

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[Matt Scorah]

Hi,

I’ll give a brief overview of what this message means, but you can find more info in the manual about some of these concepts. If you don’t want the explanation and just want the answer, it is “extend the depth frequency curve”.

EDIT: I hit the character limit, will follow up with another post

• This reply was modified 10 months ago by Matt Scorah.

[Matt Scorah]

I’m having issues with the forum right now, if you send an email to enquiries@dev7.preflight.com.au I’ll explain the theory behind that message

[Author]

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