1. Laboratory of Hydraulic Constructions (LCH), Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIC, CH-1015 Lausanne, Switzerland; formerly, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich (corresponding author).
2. M.Sc., Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, CH-8092, Zürich, Switzerland.
3. Professor, Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, CH-8092 Zürich, Switzerland.