1. Professor, Dean, II Engineering Faculty, Dept. of Civil and Environmental Engineering, Technical Univ. of Bari, via Turismo, 8, 74100 Taranto, Italy (corresponding author). E-mail: o.giustolisi@poliba.it
2. Professor, Centre for Water Systems, Univ. of Exeter, Harrison Building, North Park Rd., EX4 4QF Exeter, U.K. E-mail: d.savic@ex,ac,uk
3. Senior Lecturer, Centre for Water Systems, Univ. of Exeter, Harrison Building, North Park Rd., EX4 4QF Exeter, U.K. E-mail: z.kapelan@ex,ac,uk