LIMB 2020 IFDs Released on Data Hub
5th October 2022
The release of significantly improved Intensity-Frequency-Duration (IFD) design rainfall data in 2016 brought opportunity to renew understanding of Australian floodplains, and consequently create safer and stronger communities. However, several councils in SEQLD noted localised nuances in rainfall distribution and severity not reflected by the 2016 IFD data. A suite of new localised IFD data was hence commissioned for four local government areas (LGA), being the Lockyer Valley, Ipswich, Moreton Bay LGAs, and one other area, herein termed the LIMB 2020 IFDs.
The LIMB 2020 IFDs were informed by additional council sub-daily rainfall gauge data, and were developed using methods that placed higher weighting on this data. The method additionally placed enhanced focus on elevation. The developed localised IFDs resulted in a reduction in local biases across all AEPs, durations and areas, compared to the 2016 IFDs.
Moreton Bay Regional Council formally adopted the LIMB 2020 IFDs in June 2022 (https://www.moretonbay.qld.gov.au/files/assets/public/council/meetings/2022/gm20220629-minutes.pdf ). Ipswich City Council and Lockyer Valley Regional Council have been progressively incorporating the use of the LIMB 2020 IFDs since the conclusion of the project in June 2021.
The LIMB 2020 IFDs are now freely available for download on the ARR Data Hub website, Home | ARR Data Hub (arr-software.org) , with background information provided under the “Jurisdiction Specifics” tab. To gain the data, users enter their location of interest (e.g. 152.948 , -27.082 ), select at least one checkbox (e.g. River Region) and hit “submit”, as for usual enquiries. The LIMB IFD tables will be at the bottom of the generated results webpage. The spatial extent of the data is visible by clicking the “show” link located adjacent to the “LIMB 2020 IFD” row to the left of the map at the top of the results page.
A paper on the development of the IFDs was presented to the industry at the FMA 2022 Conference in Toowoomba; the conference paper is available via the members section of the FMA website https://www.floods.asn.au/