1. Researcher, Dept. of Hydraulics and Sanitation, Graduate Program in Water Resources and Environmental Engineering, Federal Univ. of Paraná, Centro Politécnico, Curitiba 81531-990, Brazil (corresponding author).
2. Researcher, German Federal Waterways Engineering and Research Institute, Kußmaulstraße 17, Karlsruhe 76187, Germany.
3. Professor, Dept. of Environmental Engineering, Federal Univ. of Paraná, Centro Politécnico, Curitiba 81531-990, Brazil.