1. Assistant Professor, Dept. of Civil Engineering, Federal Univ. of Sergipe (UFS), São Cristóvão, SE 49100-000, Brazil.
2. Professor, Dept. of Hydraulic and Environmental Engineering, Polytechnic School, Univ. of São Paulo (USP), São Paulo, SP 05508-900, Brazil.
3. Assistant Professor, Dept. of Hydraulic and Environmental Engineering, Polytechnic School, Univ. of São Paulo (USP), São Paulo, SP 05508-900, Brazil.
4. Distinguished Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Los Angeles, CA 90095 (corresponding author).