1. Full Professor, Faculty of Engineering, Univ. of Porto, Institute of Hydraulics and Water Resources, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal.
2. Assistant Professor, Faculty of Engineering, Univ. of Porto, Institute of Hydraulics and Water Resources, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal.
3. Administrator, Douro and Leixões Port Authority S.A., Av. da Liberdade, Apartado 3004, Leça da Palmeira, Portugal.
4. Ph.D. Researcher, Faculty of Engineering, Univ. of Porto, Institute of Hydraulics and Water Resources, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal (corresponding author).