1. Department of Water Engineering, Faculty of Agriculture; Shahrekord University, Rahbar Blvd., P.O. Box 8818634141; Shahrekord Chaharmahal and Bakhtiari Iran
2. Department of Water Engineering; Islamic Azad University, Ahar Branch; Ahar Iran
3. School of Engineering, University of St. Thomas, 2115 Summit Ave.; St. Paul MN 55105-1079.