![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
Abstract
Regional flood frequency analysis (RFFA) techniques are commonly used to estimate design floods for ungauged catchments. In Australian Rainfall and Runoff (ARR), the probabilistic rational method (PRM) was recommended for eastern New South Wales (NSW). Recent studies in Australia have shown that regression-based RFFA methods can provide more accurate design flood estimates than the PRM. This paper compares ordinary least squares (OLS) and generalised least squares (GLS) based quantile regression techniques using data from 96 small-to medium-sized catchments across NSW for average recurrence intervals of 2 to 100 years. The advantages of the GLS regression are that this accounts for the inter-station correlation and varying record lengths from site to site. An independent test based on both the split-sample and one-at-a-time validation approaches employing a wide range of statistical diagnostics indicates that the GLS regression provides more accurate flood quantile estimates than the OLS one. The developed regression equations are relatively easy to apply, which require data for only two to three predictors, catchment area, design rainfall intensity and stream density. The findings from this study together with those from other RFFA studies being examined as a part of ARR upgrade projects will inform the development of RFFA techniques for inclusion in the revised edition of ARR.
Additional information
Notes on contributors
K Haddad
Khaled Haddad is undertaking his PhD research at the University of Western Sydney. He obtained his BEng (Honours) and MEng (Honours) in Hydrology from University of Western Sydney. His research is focused on regional flood frequency analysis, with a particular emphasis on uncertainty in regional flood models and the regional modelling of large to rare floods. Prior to starting his PhD, Khaled was a floodplain management engineer with Liverpool City Council, working on many different flood mitigation and water resources projects, which included revisions to Council’s stormwater and wetlands asset management plans. Khaled is also involved in the current revision of Book 4 in Australian Rainfall and Runoff.
A Rahman
Dr Ataur Rahman is a Senior Lecturer in Water and Environmental Engineering in the School of Engineering, University of Western Sydney, Australia. He has over 18 years experiences in water industries, research and universities in Australia and southeast Asia. He obtained his BScEng degree from Khulna University of Engineering and Technology in Bangladesh, MSc (Hydrology) degree from National University of Ireland Galway, and PhD degree in Hydrology from Monash University in Australia. His research interest includes flood hydrology, urban hydrology and environmental risk assessment. He received the GN Alexander Medal from the Institution of Engineers Australia in 2002. He has published over 110 research papers in water and environmental engineering field. He is acting as Project 5 Leader (Regional flood methods in Australia) in the forthcoming revised version of Australian Rainfall and Runoff.
G Kuczera
George Kuczera is Professor of Water Engineering in the School of Engineering at the University of Newcastle. He obtained his PhD from Harvard University in 1980 and spent 5 years in the water industry before joining the University of Newcastle in 1986. His research interests cover a range of areas, including Bayesian calibration and testing of hydrologic models, stochastic hydrology and risk assessment, water resource systems analysis, and multi-criteria optimisation. He has published extensively on these topics and has developed a range of software for use in research, education and industry. George has been recipient of the GN Alexander and Warren Medals from Engineers Australia and has served as Chairman of the National Committee on Water Engineering.