1. Research Assistant, Dept. of Hydraulic Engineering, Technical Univ. of Catalunya (UPC), Barcelona, Spain. E-mail: marta.roca-collel@upc.edu
2. Associate Professor, Dept. of Hydraulic Engineering, Technical Univ. of Catalunya (UPC), Barcelona, Spain. E-mail: vide@grahi.upc.edu
3. Research Associate, ICARE-ENAC, École Polytechnique Fédérale, CH-1015 Lausanne, Switzerland. E-mail: koen.blanckaert@epfl.ch