The 2016 Intensity–Frequency–Duration (IFD) design rainfalls are provided for use in conjuction with the 2016 edition of Australian Rainfall and Runoff (ARR2016) http://arr.ga.gov.au/arr-guideline
The 2016 IFDs are:
- based on a more extensive data base, with more than 30 years of additional rainfall data and data from extra rainfall stations;
- more accurate estimates, combining contemporary statistical analysis and techniques with an expanded rainfall database; and
- better estimates of the 2% and 1% annual exceedance probability IFDs than the interim 2013 IFDs.
While access to the ARR87 IFDs and 2013 IFDs will be maintained for a short period, use of these previous estimates should be limited to the guidance provided below.
Should be used:
- for old flood studies
- to compare changes between 2016 IFDs and ARR87 IFDs
- if adopting the ARR87 Probabilistic Rational Method