Master Recession Analysis of Transmission Loss in Some Australian Streams

Abstract

A new method of constructing a master recession curve from a daily streamflow record is based on averaging recession values in 15 segments of flow range. The results from 100 records on the east coast of Australia show substantial variations in baseflow recessions from the simple exponential decay model Q _t = Q ₀ k ^t usually assumed. The difference between the theoretical exponential decay model and the actual baseflow recession is assumed to be due to transmission loss which varied from zero in two streams to a maximum of 0.186 mm/day in the other 98 catchments. The averaging of recession values in segments of flow ranges gives a master recession over the whole range of daily flows unlike just baseflow recessions as in previous methods. The new method is coded into a computer program MASTER, which automatically calculates the master recession and the transmission loss. This is much simpler than earlier methods of constructing master recessions. The method of estimating transmission loss relies on identifying a baseflow recession in the master recession and so is not suitable for use on ephemeral streams in arid and semi-arid areas but provides a means of assessing transmission loss in humid zone streams.

Key Words:

• Baseflow recession
• master recession
• recession analysis
• streamflow
• transmission loss
• hydrograph
• low flows

Additional information

Notes on contributors

W Boughton

Dr Walter Boughton is a civil engineer with an ME from the University of New South Wales and a PhD from the University of Queensland. In 19771978 he was Chairman of the College of Civil Engineers and a member of the National Council of the Institution of Engineers Australia. From 1976 to 1990, he was on the academic staff of Griffith University in the School of Australian Environmental Studies, and he was Chairman of that School in 1982–1984. Now retired, he is a hydrological consultant living in Brisbane. Walter is known for his research work in modelling the rainfall-runoff processes in catchment areas. He produced the original Boughton model in 1964, the SFB model in 1984, and the AWBM model in 1993, which is now widely used in Australia. In 1988 he was awarded the inaugural G. N. Alexander Medal by the Engineers Australia for his catchment research. In 2004, he was received the Arid Lands Hydraulic Engineering Award from the American Society of Civil Engineers. In 2014, he was inducted into the Water Engineering Hall of Fame of Engineers Australia.