[1] Hydrotec GmbH, D-52066 Aachen, Germany
[2] Danish Tech Univ, Dept Environm Sci & Engn, DK-2800 Lyngby, Denmark
[3] EAWAG, CH-8600 Dubendorf, Switzerland
[4] Norwegian Inst Technol, Dept Hydraul & Environm Engn, N-7034 Trondheim, Norway
[5] McGill Univ, Brace Res Inst, Montreal, PQ H3A 2K6, Canada
[6] Univ Belgrade, Fac Civil Engn, YU-11000 Belgrade, Yugoslavia