TY - JOUR
T1 - Regional flood frequency analysis based on peaks-over-threshold approach : a case study for South-Eastern Australia
AU - Pan, Xiao
AU - Rahman, Ataur
AU - Haddad, Khaled
AU - Ouarda, Taha B. M. J.
AU - Sharma, Ashish
N1 - Publisher Copyright:
© 2023
PY - 2023/6
Y1 - 2023/6
N2 - Study region: Southeast Australia Study focus: Regional flood frequency analysis (RFFA) is a widely adopted statistical method to estimate design floods in ungauged catchments. Annual maximum flood (AMF) model is the most popular method in developing RFFA techniques. However, the AMF-based approaches are criticised for its limitations in the range of very frequent to frequent flood estimation. As an alternative, the peaks-over-threshold (POT) based approach has shown theoretical advantages in this flood range. POT based RFFA is currently underemployed internationally due to its complexity in modelling. This study develops POT-based RFFA techniques for south-eastern Australia using data from 151 catchments. A comparison is made between ordinary least squares (OLS) and weighted least squares (WLS) methods in developing POT-based RFFA techniques. New hydrological insights for the region: The OLS based method is found to perform better than the WLS. The median relative error values of the developed prediction equations range 31-38%. The new POT-based RFFA technique overcomes the limitations of the current Australian Rainfall and Runoff, which does not have any RFFA technique for very frequent floods. It is expected that these new POT-based RFFA technique will be used in practice in south-east Australia.
AB - Study region: Southeast Australia Study focus: Regional flood frequency analysis (RFFA) is a widely adopted statistical method to estimate design floods in ungauged catchments. Annual maximum flood (AMF) model is the most popular method in developing RFFA techniques. However, the AMF-based approaches are criticised for its limitations in the range of very frequent to frequent flood estimation. As an alternative, the peaks-over-threshold (POT) based approach has shown theoretical advantages in this flood range. POT based RFFA is currently underemployed internationally due to its complexity in modelling. This study develops POT-based RFFA techniques for south-eastern Australia using data from 151 catchments. A comparison is made between ordinary least squares (OLS) and weighted least squares (WLS) methods in developing POT-based RFFA techniques. New hydrological insights for the region: The OLS based method is found to perform better than the WLS. The median relative error values of the developed prediction equations range 31-38%. The new POT-based RFFA technique overcomes the limitations of the current Australian Rainfall and Runoff, which does not have any RFFA technique for very frequent floods. It is expected that these new POT-based RFFA technique will be used in practice in south-east Australia.
UR - https://hdl.handle.net/1959.7/uws:70335
U2 - 10.1016/j.ejrh.2023.101407
DO - 10.1016/j.ejrh.2023.101407
M3 - Article
SN - 2214-5818
VL - 47
JO - Journal of Hydrology: Regional Studies
JF - Journal of Hydrology: Regional Studies
M1 - 101407
ER -
