1. Professor, Dept. of Hydraulic Structures, Shahid Chamran Univ., Ahwaz, Iran (corresponding author).
2. Professor, Dept. of Hydraulic Structures, Shahid Chamran Univ., Ahwaz, Iran.
3. Assistant Professor, Research Dept., Ministry of Agriculture, Tehran, Iran.
4. Assistant Professor, Dept. of Soil and Water Engineering, Shahrud Univ. of Technology, Shahrud, Iran.