- Title
- Non-stationarity in annual Maxima rainfall timeseries - Implications for IFD development
- Creator
- Verdon-Kidd D. C.; Kiem, Anthony S.
- Relation
- 34th Hydrology and Water Resources Symposium. Hydrology and Water Resources Symposium 2012 (Sydney 19-22 November, 2012) p. 1248-1255
- Publisher
- Engineers Australia
- Resource Type
- conference paper
- Date
- 2012
- Description
- Currently in Australia, rainfall-Intensity-Frequency-Duration (IFD) information is based on the ‘stationary climate assumption’, that weather at any point in time will vary randomly and the underlying climate statistics (including both averages and extremes) will remain constant irrespective of the period of record. The validity of this assumption for Australia has been questioned over the last 10 years following an improved understanding of the significant impact of climate variability and change occurring on interannual to multidecadal timescales. These insights did not exist when currently available IFD information was developed (25 years ago), meaning that existing IFD relationships may under- or over-estimate the design rainfall depending on the length and time period over which the rainfall data used to develop the IFD information spans. This paper provides evidence of nonstationarity in annual maxima rainfall timeseries using 92 daily rainfall stations and 66 sub-daily rainfall stations across Australia. Further, the effect of non-stationarity on the resulting IFD estimates are explored for three long-term sub-daily rainfall records (Brisbane, Sydney and Melbourne) utilising insights into multidecadal climate variability. It is recommended that non-stationarity in annual maxima rainfall be explicitly considered and appropriately treated in the ongoing revisions of Engineers Australian ‘Australian Rainfall and Runoff’ (AR&R) and that clear guidance needs to be provided on how to deal with the issue of non-stationarity of extreme events. This paper briefly outlines some improvements to the existing methodology that are worth considering.
- Subject
- rainfall intensity duration frequencies; global temperature changes; rainfall; forecasting
- Identifier
- http://hdl.handle.net/1959.13/1319615
- Identifier
- uon:23917
- Identifier
- ISBN:9781922107626
- Language
- eng
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