1. Hydraulic Engineer, Connel Wagner, Spring Hill QLD 4000, Australia; formerly, Dept. of Civil Engineering, The Univ. of Queensland, Brisbane QLD 4072, Australia.
2. Reader, Fluid Mechanics, Hydraulics and Environmental Engineering, Dept. of Civil Engineering, The Univ. of Queensland, Brisbane QLD 4072, Australia (corresponding author). E-mail: h.chanson@uq.edu.au