1. Postdoctoral Hydraulic Engineer and Researcher, Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Gloriastrasse 37-39, CH-8092 Zurich, Switzerland; formerly, Institute for Hydromechanics, Univ. of Karlsruhe, D-76128 Karlsruhe, Germany (corresponding author).
2. Research Engineer, Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Gloriastrasse 37-39, CH-8092 Zurich, Switzerland; formerly, Institute for Hydromechanics, Univ. of Karlsruhe, D-76128 Karlsruhe, Germany.
3. Emeritus Professor, Institute for Hydromechanics, Univ. of Karlsruhe, D-76128 Karlsruhe, Germany.