1. Assistant Professor, Dept. of Water Resources Engineering, Faculty of Civil Engineering, Tabriz Univ., Tabriz, Iran (corresponding author). E-mail: vnourani@yahoo.com; nourani@tabrizu.ac.ir
2. Assistant Professor, Dept. of Civil Engineering, Faculty of Engineering, Shiraz Univ., Shiraz, Iran. E-mail: monadjemi@shirazu.ac.ir
3. Caroline and William Distinguished Chair in Water Engineering and Professor, Dept. of Biological and Agricultural Engineering, Texas A&M Univ., TX 77843-2117. E-mail: vsingh@tamu.edu