1. Research Fellow, School of Environmental and Life Sciences, Univ. of Newcastle, University Drive, Callaghan, 2308 New South Wales, Australia. E-mail: Andrew.Barton@newcastle.edu.au
2. Senior Hydraulic Engineer, Hydro Tasmania Consulting, P.O. Box 355, Hobart, 7001 Tasmania, Australia. E-mail: Michael.Wallis@hydro.com.au
3. Senior Lecturer, School of Engineering, Univ. of Tasmania, Private Bag 65, Hobart, 7001 Tasmania, Australia. E-mail: Jane.Sargison@utas.edu.au
4. Ph.D. Scholar, School of Agricultural Science, Univ. of Tasmania, Private Bag 54, Hobart, 7001 Tasmania, Australia. E-mail: Alexandru.Buia@utas.edu.au
5. Visiting Research Professor, School of Engineering, Univ. of Tasmania, Private Bag 65, Hobart, 7001 Tasmania, Australia. E-mail: Greg.Walker@utas.edu.au