1. Ph.D. Candidate and Researcher, Water Resources and Environmental Engineering Research Group, Faculty of Technology, Univ. of Oulu, P.O. Box 4300, 90014 Oulu, Finland (corresponding author).
2. Professor, Water Resources and Environmental Engineering Research Group, Faculty of Technology, Univ. of Oulu, P.O. Box 4300, 90014 Oulu, Finland.