1. Senior Research Associate, Institute of Environmental Engineering, ETH Zurich, 8093 Zurich, Switzerland.
2. Director, Swiss Re, Mythenquai 50/60, P.O. Box, 8022 Zurich, Switzerland; formerly, Research Assistant, Ecole Polytechnique Fédérale de Lausanne, Laboratory of Hydraulic Constructions, 1015 Lausanne, Switzerland.
3. Professor of Hydraulic Structures, Ecole Polytechnique Fédérale de Lausanne, Laboratory of Hydraulic Constructions, Station 18, 1015 Lausanne, Switzerland (corresponding author).